Transcriber's Notes:
1. Page scan source: The Internet Web Archive
https://books.google.com/books?id=MUtBAQAAMAAJ
(the New York Public Library)

"Look out for a shot," warned
The Thinking Machine sharply. p. 332

Practically all those letters remaining in the alphabet after Augustus S. F. X. Van Dusen was named were afterward acquired by that gentleman in the course of a brilliant scientific career, and, being honorably acquired, were tacked on to the other end. His name, therefore, taken with all that belonged to it, was a wonderfully imposing structure. He was a Ph.D., an LL.D., an F.R.S., an M.D., and an M.D.S. He was also some other things--just what he himself couldn't say--through recognition of his ability by various foreign educational and scientific institutions.

In appearance he was no less striking than in nomenclature. He was slender with the droop of the student in his thin shoulders and the pallor of a close, sedentary life on his clean-shaven face. His eyes wore a perpetual, forbidding squint--the squint of a man who studies little things--and when they could be seen at all through his thick spectacles, were mere slits of watery blue. But above his eyes was his most striking feature. This was a tall, broad brow, almost abnormal in height and width, crowned by a heavy shock of bushy, yellow hair. All these things conspired to give him a peculiar, almost grotesque, personality.

Professor Van Dusen was remotely German. For generations his ancestors had been noted in the sciences; he was the logical result, the master mind. First and above all he was a logician. At least thirty-five years of the half-century or so of his existence had been devoted exclusively to proving that two and two always equal four, except in unusual cases, where they equal three or five, as the case may be. He stood broadly on the general proposition that all things that start must go somewhere, and was able to bring the concentrated mental force of his forefathers to bear on a given problem. Incidentally it may be remarked that Professor Van Dusen wore a No. 8 hat.

The world at large had heard vaguely of Professor Van Dusen as The Thinking Machine. It was a newspaper catch-phrase applied to him at the time of a remarkable exhibition at chess; he had demonstrated then that a stranger to the game might, by the force of inevitable logic, defeat a champion who had devoted a lifetime to its study. The Thinking Machine! Perhaps that more nearly described him than all his honorary initials, for he spent week after week, month after month, in the seclusion of his small laboratory from which had gone forth thoughts that staggered scientific associates and deeply stirred the world at large.

It was only occasionally that The Thinking Machine had visitors, and these were usually men who, themselves high in the sciences, dropped in to argue a point and perhaps convince themselves. Two of these men, Dr. Charles Ransome and Alfred Fielding, called one evening to discuss some theory which is not of consequence here.

"Such a thing is impossible," declared Dr. Ransome emphatically, in the course of the conversation.

"Nothing is impossible," declared The Thinking Machine with equal emphasis. He always spoke petulantly. "The mind is master of all things. When science fully recognizes that fact a great advance will have been made."

"How about the airship?" asked Dr. Ransome.

"That's not impossible at all," asserted The Thinking Machine. "It will be invented some time. I'd do it myself, but I'm busy."

Dr. Ransome laughed tolerantly.

"I've heard you say such things before," he said. "But they mean nothing. Mind may be master of matter, but it hasn't yet found a way to apply itself. There are some things that can't be thought out of existence, or rather which would not yield to any amount of thinking."

"What, for instance?" demanded The Thinking Machine.

Dr. Ransome was thoughtful for a moment as he smoked.

"Well, say prison walls," he replied. "No man can _think_ himself out of a cell. If he could, there would be no prisoners."

"A man can so apply his brain and ingenuity that he can leave a cell, which is the same thing," snapped The Thinking Machine.

Dr. Ransome was slightly amused.

"Let's suppose a case," he said, after a moment. "Take a cell where prisoners under sentence of death are confined--men who are desperate and, maddened by fear, would take any chance to escape--suppose you were locked in such a cell. Could you escape?"

"Certainly," declared The Thinking Machine.

"Of course," said Mr. Fielding, who entered the conversation for the first time, "you might wreck the cell with an explosive--but inside, a prisoner, you couldn't have that."

"There would be nothing of that kind," said The Thinking Machine. "You might treat me precisely as you treated prisoners under sentence of death, and I would leave the cell."

"Not unless you entered it with tools prepared to get out," said Dr. Ransome.

The Thinking Machine was visibly annoyed and his blue eyes snapped.

"Lock me in any cell in any prison anywhere at any time, wearing only what is necessary, and I'll escape in a week," he declared, sharply.

Dr. Ransome sat up straight in the chair, interested. Mr. Fielding lighted a new cigar.

"You mean you could actually _think_ yourself out?" asked Dr. Ransome.

"I would get out," was the response.

"Are you serious?"

"Certainly I am serious."

Dr. Ransome and Mr. Fielding were silent for a long time.

"Would you be willing to try it?" asked Mr. Fielding, finally.

"Certainly," said Professor Van Dusen, and there was a trace of irony in his voice. "I have done more asinine things than that to convince other men of less important truths."

The tone was offensive and there was an undercurrent strongly resembling anger on both sides. Of course it was an absurd thing, but Professor Van Dusen reiterated his willingness to undertake the escape and it was decided upon.

"To begin now," added Dr. Ransome.

"I'd prefer that it begin to-morrow," said The Thinking Machine, "because----"

"No, now," said Mr. Fielding, flatly. "You are arrested, figuratively, of course, without any warning locked in a cell with no chance to communicate with friends, and left there with identically the same care and attention that would be given to a man under sentence of death. Are you willing?"

"All right, now, then," said The Thinking Machine, and he arose.

"Say, the death-cell in Chisholm Prison."

"The death-cell in Chisholm Prison."

"And what will you wear?"

"As little as possible," said The Thinking Machine. "Shoes, stockings, trousers and a shirt."

"You will permit yourself to be searched, of course?"

"I am to be treated precisely as all prisoners are treated," said The Thinking Machine. "No more attention and no less."

There were some preliminaries to be arranged in the matter of obtaining permission for the test, but all three were influential men and everything was done satisfactorily by telephone, albeit the prison commissioners, to whom the experiment was explained on purely scientific grounds, were sadly bewildered. Professor Van Dusen would be the most distinguished prisoner they had ever entertained.

When The Thinking Machine had donned those things which he was to wear during his incarceration he called the little old woman who was his housekeeper, cook and maid servant all in one.

"Martha," he said, "it is now twenty-seven minutes past nine o'clock. I am going away. One week from to-night, at half-past nine, these gentlemen and one, possibly two, others will take supper with me here. Remember Dr. Ransome is very fond of artichokes."

The three men were driven to Chisholm Prison, where the Warden was awaiting them, having been informed of the matter by telephone. He understood merely that the eminent Professor Van Dusen was to be his prisoner, if he could keep him, for one week; that he had committed no crime, but that he was to be treated as all other prisoners were treated.

"Search him," instructed Dr. Ransome.

The Thinking Machine was searched. Nothing was found on him; the pockets of the trousers were empty; the white, stiff-bosomed shirt had no pocket. The shoes and stockings were removed, examined, then replaced. As he watched all these preliminaries--the rigid search and noted the pitiful, childlike physical weakness of the man, the colorless face, and the thin, white hands--Dr. Ransome almost regretted his part in the affair.

"Are you sure you want to do this?" he asked.

"Would you be convinced if I did not?" inquired The Thinking Machine in turn.

"No."

"All right. I'll do it."

What sympathy Dr. Ransome had was dissipated by the tone. It nettled him, and he resolved to see the experiment to the end; it would be a stinging reproof to egotism.

"It will be impossible for him to communicate with anyone outside?" he asked.

"Absolutely impossible," replied the warden. "He will not be permitted writing materials of any sort."

"And your jailers, would they deliver a message from him?"

"Not one word, directly or indirectly," said the warden. "You may rest assured of that. They will report anything he might say or turn over to me anything he might give them."

"That seems entirely satisfactory," said Mr. Fielding, who was frankly interested in the problem.

"Of course, in the event he fails," said Dr. Ransome, "and asks for his liberty, you understand you are to set him free?"

"I understand," replied the warden.

The Thinking Machine stood listening, but had nothing to say until this was all ended, then:

"I should like to make three small requests. You may grant them or not, as you wish."

"No special favors, now," warned Mr. Fielding.

"I am asking none," was the stiff response. "I would like to have some tooth powder--buy it yourself to see that it is tooth powder--and I should like to have one five-dollar and two ten-dollar bills."

Dr. Ransome, Mr. Fielding and the warden exchanged astonished glances. They were not surprised at the request for tooth powder, but were at the request for money.

"Is there any man with whom our friend would come in contact that he could bribe with twenty-five dollars?" asked Dr. Ransome of the warden.

"Not for twenty-five hundred dollars," was the positive reply.

"Well, let him have them," said Mr. Fielding. "I think they are harmless enough."

"And what is the third request?" asked Dr. Ransome.

"I should like to have my shoes polished."

Again the astonished glances were exchanged. This last request was the height of absurdity, so they agreed to it. These things all being attended to, The Thinking Machine was led back into the prison from which he had undertaken to escape.

"Here is Cell 13," said the warden, stopping three doors down the steel corridor. "This is where we keep condemned murderers. No one can leave it without my permission; and no one in it can communicate with the outside. I'll stake my reputation on that. It's only three doors back of my office and I can readily hear any unusual noise."

"Will this cell do, gentlemen?" asked The Thinking Machine. There was a touch of irony in his voice.

"Admirably," was the reply.

The heavy steel door was thrown open, there was a great scurrying and scampering of tiny feet, and The Thinking Machine passed into the gloom of the cell. Then the door was closed and double locked by the warden.

"What is that noise in there?" asked Dr. Ransome, through the bars.

"Rats--dozens of them," replied The Thinking Machine, tersely.

The three men, with final goodnights, were turning away when The Thinking Machine called:

"What time is it exactly, warden?"

"Eleven seventeen," replied the warden.

"Thanks. I will join you gentlemen in your office at half-past eight o'clock one week from to-night," said The Thinking Machine.

"And if you do not?"

"There is no 'if' about it."

Chisholm Prison was a great, spreading structure of granite, four stories in all, which stood in the center of acres of open space. It was surrounded by a wall of solid masonry eighteen feet high, and so smoothly finished inside and out as to offer no foothold to a climber, no matter how expert. Atop of this fence, as a further precaution, was a five-foot fence of steel rods, each terminating in a keen point. This fence in itself marked an absolute deadline between freedom and imprisonment, for, even if a man escaped from his cell, it would seem impossible for him to pass the wall.

The yard, which on all sides of the prison building was twenty-five feet wide, that being the distance from the building to the wall, was by day an exercise ground for those prisoners to whom was granted the boon of occasional semi-liberty. But that was not for those in Cell 13. At all times of the day there were armed guards in the yard, four of them, one patrolling each side of the prison building.

By night the yard was almost as brilliantly lighted as by day. On each of the four sides was a great arc light which rose above the prison wall and gave to the guards a clear sight. The lights, too, brightly illuminated the spiked top of the wall. The wires which fed the arc lights ran up the side of the prison building on insulators and from the top story led out to the poles supporting the arc lights.

All these things were seen and comprehended by The Thinking Machine, who was only enabled to see out his closely barred cell window by standing on his bed. This was on the morning following his incarceration. He gathered, too, that the river lay over there beyond the wall somewhere, because he heard faintly the pulsation of a motor boat and high up in the air saw a river bird. From that same direction came the shouts of boys at play and the occasional crack of a batted ball. He knew then that between the prison wall and the river was an open space, a playground.

Chisholm Prison was regarded as absolutely safe. No man had ever escaped from it. The Thinking Machine, from his perch on the bed, seeing what he saw, could readily understand why. The walls of the cell, though built he judged twenty years before, were perfectly solid, and the window bars of new iron had not a shadow of rust on them. The window itself, even with the bars out, would be a difficult mode of egress because it was small.

Yet, seeing these things, The Thinking Machine was not discouraged. Instead, he thoughtfully squinted at the great arc light--there was bright sunlight now--and traced with his eyes the wire which led from it to the building. That electric wire, he reasoned, must come down the side of the building not a great distance from his cell. That might be worth knowing.

Cell 13 was on the same floor with the offices of the prison--that is, not in the basement, nor yet upstairs. There were only four steps up to the office floor, therefore the level of the floor must be only three or four feet above the ground. He couldn't see the ground directly beneath his window, but he could see it further out toward the wall. It would be an easy drop from the window. Well and good.

Then The Thinking Machine fell to remembering how he had come to the cell. First, there was the outside guard's booth, a part of the wall. There were two heavily barred gates there, both of steel. At this gate was one man always on guard. He admitted persons to the prison after much clanking of keys and locks, and let them out when ordered to do so. The warden's office was in the prison building, and in order to reach that official from the prison yard one had to pass a gate of solid steel with only a peep-hole in it. Then coming from that inner office to Cell 13, where he was now, one must pass a heavy wooden door and two steel doors into the corridors of the prison; and always there was the double-locked door of Cell 13 to reckon with.

There were then, The Thinking Machine recalled, seven doors to be overcome before one could pass from Cell 13 into the outer world, a free man. But against this was the fact that he was rarely interrupted. A jailer appeared at his cell door at six in the morning with a breakfast of prison fare; he would come again at noon, and again at six in the afternoon. At nine o'clock at night would come the inspection tour. That would be all.

"It's admirably arranged, this prison system," was the mental tribute paid by The Thinking Machine. "I'll have to study it a little when I get out. I had no idea there was such great care exercised in the prisons."

There was nothing, positively nothing, in his cell, except his iron bed, so firmly put together that no man could tear it to pieces save with sledges or a file. He had neither of these. There was not even a chair, or a small table, or a bit of tin or crockery. Nothing! The jailer stood by when he ate, then took away the wooden spoon and bowl which he had used.

One by one these things sank into the brain of The Thinking Machine. When the last possibility had been considered he began an examination of his cell. From the roof, down the walls on all sides, he examined the stones and the cement between them. He stamped over the floor carefully time after time, but it was cement, perfectly solid. After the examination he sat on the edge of the iron bed and was lost in thought for a long time. For Professor Augustus S. F. X. Van Dusen, The Thinking Machine, had something to think about.

He was disturbed by a rat, which ran across his foot, then scampered away into a dark corner of the cell, frightened at its own daring. After awhile The Thinking Machine, squinting steadily into the darkness of the corner where the rat had gone, was able to make out in the gloom many little beady eyes 'staring at him. He counted six pair, and there were perhaps others; he didn't see very well.

Then The Thinking Machine, from his seat on the bed, noticed for the first time the bottom of his cell door. There was an opening there of two inches between the steel bar and the floor. Still looking steadily at this opening, The Thinking Machine backed suddenly into the corner where he had seen the beady eyes. There was a great scampering of tiny feet, several squeaks of frightened rodents, and then silence.

None of the rats had gone out the door, yet there were none in the cell. Therefore there must be another way out of the cell, however small. The Thinking Machine, on hands and knees, started a search for this spot, feeling in the darkness with his long, slender fingers.

At last his search was rewarded. He came upon a small opening in the floor, level with the cement. It was perfectly round and somewhat larger than a silver dollar. This was the way the rats had gone. He put his fingers deep into the opening; it seemed to be a disused drainage pipe and was dry and dusty.

Having satisfied himself on this point, he sat on the bed again for an hour, then made another inspection of his surroundings through the small cell window. One of the outside guards stood directly opposite, beside the wall, and happened to be looking at the window of Cell 13 when the head of The Thinking Machine appeared. But the scientist didn't notice the guard.

Noon came and the jailer appeared with the prison dinner of repulsively plain food. At home The Thinking Machine merely ate to live; here he took what was offered without comment. Occasionally he spoke to the jailer who stood outside the door watching him.

"Any improvements made here in the last few years?" he asked.

"Nothing particularly," replied the jailer. "New wall was built four years ago."

"Anything done to the prison proper?"

"Painted the woodwork outside, and I believe about seven years ago a new system of plumbing was put in."

"Ah!" said the prisoner. "How far is the river over there?"

"About three hundred feet. The boys have a baseball ground between the wall and the river." The Thinking Machine had nothing further to say just then, but when the jailer was ready to go he asked for some water.

"I get very thirsty here," he explained. "Would it be possible for you to leave a little water in a bowl for me?"

"I'll ask the warden," replied the jailer, and he went away.

Half an hour later he returned with water in a small earthen bowl.

"The warden says you may keep this bowl," he informed the prisoner. "But you must show it to me when I ask for it. If it is broken, it will be the last."

"Thank you," said The Thinking Machine. "I shan't break it."

The jailer went on about his duties. For just the fraction of a second it seemed that The Thinking Machine wanted to ask a question, but he didn't.

Two hours later this same jailer, in passing the door of Cell No. 13, heard a noise inside and stopped. The Thinking Machine was down on his hands and knees in a corner of the cell, and from that same corner came several frightened squeaks. The jailer looked on interestedly.

"Ah, I've got you," he heard the prisoner say. "Got what?" he asked, sharply.

"One of these rats," was the reply. "See?" And between the scientist's long fingers the jailer saw a small gray rat struggling. The prisoner brought it over to the light and looked at it closely. "It's a water rat," he said.

"Ain't you got anything better to do than to catch rats?" asked the jailer.

"It's disgraceful that they should be here at all," was the irritated reply. "Take this one away and kill it. There are dozens more where it came from."

The jailer took the wriggling, squirmy rodent and flung it down on the floor violently. It gave one squeak and lay still. Later he reported the incident to the warden, who only smiled.

Still later that afternoon the outside armed guard on Cell 13 side of the prison looked up again at the window and saw the prisoner looking out. He saw a hand raised to the barred window and then something white fluttered to the ground, directly under the window of Cell 13. It was a little roll of linen, evidently of white shirting material, and tied around it was a five-dollar bill. The guard looked up at the window again, but the face had disappeared.

With a grim smile he took the little linen roll and the five-dollar bill to the warden's office. There together they deciphered something which was written on it with a queer sort of ink, frequently blurred. On the outside was this:

"Finder of this please deliver to Dr. Charles Ransome."

"Ah," said the warden, with a chuckle. "Plan of escape number one has gone wrong." Then, as an afterthought: "But why did he address it to Dr. Ransome?"

"And where did he get the pen and ink to write with?" asked the guard.

The warden looked at the guard and the guard looked at the warden. There was no apparent solution of that mystery. The warden studied the writing carefully, then shook his head.

"Well, let's see what he was going to say to Dr. Ransome," he said at length, still puzzled, and he unrolled the inner piece of linen.

"Well, if that--what--what do you think of that?" he asked, dazed.

The guard took the bit of linen and read this:

"_Epa cseot d'net niiy awe htto n'si sih. 'T'"_.

The warden spent an hour wondering what sort of a cipher it was, and half an hour wondering why his prisoner should attempt to communicate with Dr. Ransome, who was the cause of him being there. After this the warden devoted some thought to the question of where the prisoner got writing materials, and what sort of writing materials he had. With the idea of illuminating this point, he examined the linen again. It was a torn part of a white shirt and had ragged edges.

Now it was possible to account for the linen, but what the prisoner had used to write with was another matter. The warden knew it would have been impossible for him to have either pen or pencil, and, besides, neither pen nor pencil had been used in this writing. What, then? The warden decided to personally investigate. The Thinking Machine was his prisoner; he had orders to hold his prisoners; if this one sought to escape by sending cipher messages to persons outside, he would stop it, as he would have stopped it in the case of any other prisoner.

The warden went back to Cell 13 and found The Thinking Machine on his hands and knees on the floor, engaged in nothing more alarming than catching rats. The prisoner heard the warden's step and turned to him quickly.

"It's disgraceful," he snapped, "these rats. There are scores of them."

"Other men have been able to stand them," said the warden. "Here is another shirt for you--let me have the one you have on."

"Why?" demanded The Thinking Machine, quickly. His tone was hardly natural, his manner suggested actual perturbation.

"You have attempted to communicate with Dr. Ransome," said the warden severely. "As my prisoner, it is my duty to put a stop to it."

The Thinking Machine was silent for a moment.

"All right," he said, finally. "Do your duty."

The warden smiled grimly. The prisoner arose from the floor and removed the white shirt, putting on instead a striped convict shirt the warden had brought. The warden took the white shirt eagerly, and then and there compared the pieces of linen on which was written the cipher with certain torn places in the shirt. The Thinking Machine looked on curiously.

"The guard brought _you_ those, then?" he asked.

"He certainly did," replied the warden triumphantly. "And that ends your first attempt to escape."

The Thinking Machine watched the warden as he, by comparison, established to his own satisfaction that only two pieces of linen had been torn from the white shirt.

"What did you write this with?" demanded the warden.

"I should think it a part of your duty to find out," said The Thinking Machine, irritably.

The warden started to say some harsh things, then restrained himself and made a minute search of the cell and of the prisoner instead. He found absolutely nothing; not even a match or toothpick which might have been used for a pen. The same mystery surrounded the fluid with which the cipher had been written. Although the warden left Cell 13 visibly annoyed, he took the torn shirt in triumph.

"Well, writing notes on a shirt won't get him out, that's certain," he told himself with some complacency. He put the linen scraps into his desk to await developments. "If that man escapes from that cell I'll--hang it-I'll resign."

On the third day of his incarceration The Thinking Machine openly attempted to bribe his way out. The jailer had brought his dinner and was leaning against the barred door, waiting, when The Thinking Machine began the conversation.

"The drainage pipes of the prison lead to the river, don't they?" he asked.

"Yes," said the jailer.

"I suppose they are very small?"

"Too small to crawl through, if that's what you're thinking about," was the grinning response.

There was silence until The Thinking Machine finished his meal. Then:

"You know I'm not a criminal, don't you?"

"Yes."

"And that I've a perfect right to be freed if I demand it?"

"Yes."

"Well, I came here believing that I could make my escape," said the prisoner, and his squint eyes studied the face of the jailer. "Would you consider a financial reward for aiding me to escape?"

The jailer, who happened to be an honest man, looked at the slender, weak figure of the prisoner, at the large head with its mass of yellow hair, and was almost sorry.

"I guess prisons like these were not built for the likes of you to get out of," he said, at last.

"But would you consider a proposition to help me get out?" the prisoner insisted, almost beseechingly.

"No," said the jailer, shortly.

"Five hundred dollars," urged The Thinking Machine. "I am not a criminal."

"No," said the jailer.

"A thousand?"

"No," again said the jailer, and he started away hurriedly to escape further temptation. Then he turned back. "If you should give me ten thousand dollars I couldn't get you out. You'd have to pass through seven doors, and I only have the keys to two."

Then he told the warden all about it.

"Plan number two fails," said the warden, smiling grimly. "First a cipher, then bribery."

When the jailer was on his way to Cell 13 at six o'clock, again bearing food to The Thinking Machine, he paused, startled by the unmistakable scrape, scrape of steel against steel. It stopped at the sound of his steps, then craftily the jailer, who was beyond the prisoner's range of vision, resumed his tramping, the sound being apparently that of a man going away from Cell 13. As a matter of fact he was in the same spot.

After a moment there came again the steady scrape, scrape, and the jailer crept cautiously on tiptoes to the door and peered between the bars. The Thinking Machine was standing on the iron bed working at the bars of the little window. He was using a file, judging from the backward and forward swing of his arms.

Cautiously the jailer crept back to the office, summoned the warden in person, and they returned to Cell 13 on tiptoes. The steady scrape was still audible. The warden listened to satisfy himself and then suddenly appeared at the door.

"Well?" he demanded, and there was a smile on his face.

The Thinking Machine glanced back from his perch on the bed and leaped suddenly to the floor, making frantic efforts to hide something. The warden went in, with hand extended.

"Give it up," he said.

"No," said the prisoner, sharply.

"Come, give it up," urged the warden. "I don't want to have to search you again."

"No," repeated the prisoner.

"What was it, a file?" asked the warden.

The Thinking Machine was silent and stood squinting at the warden with something very nearly approaching disappointment on his face--nearly, but not quite. The warden was almost sympathetic.

"Plan number three fails, eh?" he asked, good-naturedly. "Too bad, isn't it?"

The prisoner didn't say.

"Search him," instructed the warden.

The jailer searched the prisoner carefully. At last, artfully concealed in the waist band of the trousers, he found a piece of steel about two inches long, with one side curved like a half moon.

"Ah," said the warden, as he received it from the jailer. "From your shoe heel," and he smiled pleasantly.

The jailer continued his search and on the other side of the trousers waist band found another piece of steel identical with the first. The edges showed where they had been worn against the bars of the window.

"You couldn't saw a way through those bars with these," said the warden.

"I could have," said The Thinking Machine firmly.

"In six months, perhaps," said the warden, good-naturedly.

The warden shook his head slowly as he gazed into the slightly flushed face of his prisoner.

"Ready to give it up?" he asked.

"I haven't started yet," was the prompt reply.

Then came another exhaustive search of the cell. Carefully the two men went over it, finally turning out the bed and searching that. Nothing. The warden in person climbed upon the bed and examined the bars of the window where the prisoner had been sawing. When he looked he was amused.

"Just made it a little bright by hard rubbing," he said to the prisoner, who stood looking on with a somewhat crestfallen air. The warden grasped the iron bars in his strong hands and tried to shake them. They were immovable, set firmly in the solid granite. He examined each in turn and found them all satisfactory. Finally he climbed down from the bed.

"Give it up, professor," he advised.

The Thinking Machine shook his head and the warden and jailer passed on again. As they disappeared down the corridor The Thinking Machine sat on the edge of the bed with his head in his hands.

"He's crazy to try to get out of that cell," commented the jailer.

"Of course he can't get out," said the warden. "But he's clever. I would like to know what he wrote that cipher with."

* * * * *

It was four o'clock next morning when an awful, heart-racking shriek of terror resounded through the great prison. It came from a cell, somewhere about the center, and its tone told a tale of horror, agony, terrible fear. The warden heard and with three of his men rushed into the long corridor leading to Cell 13.

As they ran there came again that awful cry. It died away in a sort of wail. The white faces of prisoners appeared at cell doors upstairs and down, staring out wonderingly, frightened.

"It's that fool in Cell 13," grumbled the warden.

He stopped and stared in as one of the jailers flashed a lantern. "That fool in Cell 13" lay comfortably on his cot, flat on his back with his mouth open, snoring. Even as they looked there came again the piercing cry, from somewhere above. The warden's face blanched a little as he started up the stairs. There on the top floor he found a man in Cell 43, directly above Cell 13, but two floors higher, cowering in a corner of his cell.

"What's the matter?" demanded the warden.

"Thank God you've come," exclaimed the prisoner, and he cast himself against the bars of his cell.

"What is it?" demanded the warden again.

He threw open the door and went in. The prisoner dropped on his knees and clasped the warden about the body. His face was white with terror, his eyes were widely distended, and he was shuddering. His hands, icy cold, clutched at the warden's.

"Take me out of this cell, please take me out," he pleaded.

"What's the matter with you, anyhow?" insisted the warden, impatiently.

"I heard something--something," said the prisoner, and his eyes roved nervously around the cell.

"What did you hear?"

"I--I can't tell you," stammered the prisoner. Then, in a sudden burst of terror: "Take me out of this cell--put me anywhere--but take me out of here."

The warden and the three jailers exchanged glances.

"Who is this fellow? What's he accused of?" asked the warden.

"Joseph Ballard," said one of the jailers. "He's accused of throwing acid in a woman's face. She died from it."

"But they can't prove it," gasped the prisoner. "They can't prove it. Please put me in some other cell."

He was still clinging to the warden, and that official threw his arms off roughly. Then for a time he stood looking at the cowering wretch, who seemed possessed of all the wild, unreasoning terror of a child.

"Look here, Ballard," said the warden, finally, "if you heard anything, I want to know what it was. Now tell me."

"I can't, I can't," was the reply. He was sobbing. "Where did it come from?"

"I don't know. Everywhere--nowhere. I just heard it."

"What was it--a voice?"

"Please don't make me answer," pleaded the prisoner.

"You must answer," said the warden, sharply.

"It was a voice--but--but it wasn't human," was the sobbing reply.

"Voice, but not human?" repeated the warden, puzzled.

"It sounded muffled and--and far away--and ghostly," explained the man.

"Did it come from inside or outside the prison?"

"It didn't seem to come from anywhere--it was just here, here, everywhere. I heard it. I heard it."

For an hour the warden tried to get the story, but Ballard had become suddenly obstinate and would say nothing--only pleaded to be placed in another cell, or to have one of the jailers remain near him until daylight. These requests were gruffly refused.

"And see here," said the warden, in conclusion, "if there's any more of this screaming I'll put you in the padded cell."

Then the warden went his way, a sadly puzzled man. Ballard sat at his cell door until daylight, his face, drawn and white with terror, pressed against the bars, and looked out into the prison with wide. staring eyes.

That day, the fourth since the incarceration of The Thinking Machine, was enlivened considerably by the volunteer prisoner, who spent most of his time at the little window of his cell. He began proceedings by throwing another piece of linen down to the guard, who picked it up dutifully and took it to the warden. On it was written:

"Only three days more."

The warden was in no way surprised at what he read; he understood that The Thinking Machine meant only three days more of his imprisonment, and he regarded the note as a boast. But how was the thing written? Where had The Thinking Machine found this new piece of linen? Where? How? He carefully examined the linen. It was white, of fine texture, shirting material. He took the shirt which he had taken and carefully fitted the two original pieces of the linen to the torn places. This third piece was entirely superfluous; it didn't fit anywhere, and yet it was unmistakably the same goods.

"And where--where does he get anything to write with?" demanded the warden of the world at large.

Still later on the fourth day The Thinking Machine, through the window of his cell, spoke to the armed guard outside.

"What day of the month is it?" he asked.

"The fifteenth," was the answer.

The Thinking Machine made a mental Astronomical calculation and satisfied himself that the moon would not rise until after nine o'clock that night. Then he asked another question:

"Who attends to those arc lights?"

"Man from the company."

"You have no electricians in the building?"

"I should think you could save money if you had your own man."

"None of my business," replied the guard.

The guard noticed The Thinking Machine at the cell window frequently during that day, but always the face seemed listless and there was a certain wistfulness in the squint eyes behind the glasses. After a while he accepted the presence of the leonine head as a matter of course. He had seen other prisoners do the same thing; it was the longing for the outside world.

That afternoon, just before the day guard was relieved, the head appeared at the window again, and The Thinking Machine's hand held something out between the bars. It fluttered to the ground and the guard picked it up. It was a five-dollar bill.

"That's for you," called the prisoner.

As usual, the guard took it to the warden. That gentleman looked at it suspiciously; he looked at everything that came from Cell 13 with suspicion.

"He said it was for me," explained the guard.

"It's a sort of a tip, I suppose," said the warden. "I see no particular reason why you shouldn't accept----"

Suddenly he stopped. He had remembered that The Thinking Machine had gone into Cell 13 with one five-dollar bill and two ten-dollar bills; twenty-five dollars in all. Now a five-dollar bill had been tied around the first pieces of linen that came from the cell. The warden still had it, and to convince himself he took it out and looked at it. It was five dollars; yet here was another five dollars, and The Thinking Machine had only had ten-dollar bills.

"Perhaps somebody changed one of the bills for him," he thought at last, with a sigh of relief.

But then and there he made up his mind. He would search Cell 13 as a cell was never before searched in this world. When a man could write at will, and change money, and do other wholly inexplicable things, there was something radically wrong with his prison. He planned to enter the cell at night--three o'clock would be an excellent time. The Thinking Machine must do all the weird things he did sometime. Night seemed the most reasonable.

Thus it happened that the warden stealthily descended upon Cell 13 that night at three o'clock. He paused at the door and listened. There was no sound save the steady, regular breathing of the prisoner. The keys unfastened the double locks with scarcely a clank, and the warden entered, locking the door behind him. Suddenly he flashed his dark-lantern in the face of the recumbent figure.

If the warden had planned to startle The Thinking Machine he was mistaken, for that individual merely opened his eyes quietly, reached for his glasses and inquired, in a most matter-of-fact tone:

"Who is it?"

It would be useless to describe the search that the warden made. It was minute. Not one inch of the cell or the bed was overlooked. He found the round hole in the floor, and with a flash of inspiration thrust his thick fingers into it. After a moment of fumbling there he drew up something and looked at it in the light of his lantern.

"Ugh!" he exclaimed.

The thing he had taken out was a rat--a dead rat. His inspiration fled as a mist before the sun. But he continued the search. The Thinking Machine, without a word, arose and kicked the rat out of the cell into the corridor.

The warden climbed on the bed and tried the steel bars in the tiny window. They were perfectly rigid; every bar of the door was the same.

Then the warden searched the prisoner's clothing, beginning at the shoes. Nothing hidden in them! Then the trousers waist band. Still nothing! Then the pockets of the trousers. From one side he drew out some paper money and examined it.

"Five one-dollar bills," he gasped.

"That's right," said the prisoner.

"But the--you had two tens and a five--what the--how do you do it?"

"That's my business," said The Thinking Machine.

"Did any of my men change this money for you--on your word of honor?"

The Thinking Machine paused just a fraction of a second.

"No," he said.

"Well, do you make it?" asked the warden. He was prepared to believe anything.

"That's my business," again said the prisoner.

The warden glared at the eminent scientist fiercely. He felt--he knew--that this man was making a fool of him, yet he didn't know how. If he were a real prisoner he would get the truth--but, then, perhaps, those inexplicable things which had happened would not have been brought before him so sharply. Neither of the men spoke for a long time, then suddenly the warden turned fiercely and left the cell, slamming the door behind him. He didn't dare to speak, then.

He glanced at the clock. It was ten minutes to four. He had hardly settled himself in bed when again came that heart-breaking shriek through the prison. With a few muttered words, which, while not elegant, were highly expressive, he relighted his lantern and rushed through the prison again to the cell on the upper floor.

Again Ballard was crushing himself against the steel door, shrieking, shrieking at the top of his voice. He stopped only when the warden flashed his lamp in the cell.

"Take me out, take me out," he screamed. "I did it, I did it, I killed her. Take it away."

"Take what away?" asked the warden.

"I threw the acid in her face--I did it--I confess. Take me out of here."

Ballard's condition was pitiable; it was only an act of mercy to let him out into the corridor. There he crouched in a corner, like an animal at bay, and clasped his hands to his ears. It took half an hour to calm him sufficiently for him to speak. Then he told incoherently what had happened. On the night before at four o'clock he had heard a voice--a sepulchral voice, muffled and wailing in tone.

"What did it say?" asked the warden, curiously.

"Acid--acid--acid!" gasped the prisoner. "It accused me. Acid! I threw the acid, and the woman died. Oh!" It was a long, shuddering wail of terror.

"Acid?" echoed the warden, puzzled. The case was beyond him.

"Acid. That's all I heard--that one word, repeated several times. There were other things, too, but I didn't hear them."

"That was last night, eh?" asked the warden. "What happened to-night--what frightened you just now?"

"It was the same thing," gasped the prisoner. "Acid--acid--acid!" He covered his face with his hands and sat shivering. "It was acid I used on her, but I didn't mean to kill her. I just heard the words. It was something accusing me--accusing me." He mumbled, and was silent.

"Did you hear anything else?"

"Yes--but I couldn't understand--only a little bit--just a word or two."

"Well, what was it?"

"I heard 'acid' three times, then I heard a long, moaning sound, then--then--I heard 'No. 8 hat.' I heard that twice."

"No. 8 hat," repeated the warden. "What the devil--No. 8 hat? Accusing voices of conscience have never talked about No. 8 hats, so far as I ever heard."

"He's insane," said one of the jailers, with an air of finality.

"I believe you," said the warden. "He must be. He probably heard something and got frightened. He's trembling now. No. 8 hat! What the----"

When the fifth day of The Thinking Machine's imprisonment rolled around the warden was wearing a hunted look. He was anxious for the end of the thing. He could not help but feel that his distinguished prisoner had been amusing himself. And if this were so, The Thinking Machine had lost none of his sense of humor. For on this fifth day he flung down another linen note to the outside guard, bearing the words: "Only two days more." Also he flung down half a dollar.

Now the warden knew--he _knew_--that the man in Cell 13 didn't have any half dollars--he _couldn't_ have any half dollars, no more than he could have pen and ink and linen, and yet he did have them. It was a condition, not a theory; that is one reason why the warden was wearing a hunted look.

That ghastly, uncanny thing, too, about "Acid" and "No. 8 hat" clung to him tenaciously. They didn't mean anything, of course, merely the ravings of an insane murderer who had been driven by fear to confess his crime, still there were so many things that "didn't mean anything" happening in the prison now since The Thinking Machine was there.

On the sixth day the warden received a postal stating that Dr. Ransome and Mr. Fielding would be at Chisholm Prison on the following evening, Thursday, and in the event Professor Van Dusen had not yet escaped--and they presumed he had not because they had not heard from him--they would meet him there.

"In the event he had not yet escaped!" The warden smiled grimly. Escaped!

The Thinking Machine enlivened this day for the warden with three notes. They were on the usual linen and bore generally on the appointment at half-past eight o'clock Thursday night, which appointment the scientist had made at the time of his imprisonment.

On the afternoon of the seventh day the warden passed Cell 13 and glanced in. The Thinking Machine was lying on the iron bed, apparently sleeping lightly. The cell appeared precisely as it always did from a casual glance. The warden would swear that no man was going to leave it between that hour--it was then four o'clock--and half-past eight o'clock that evening.

On his way back past the cell the warden heard the steady breathing again, and coming close to the door looked in. He wouldn't have done so if The Thinking Machine had been looking, but now--well, it was different.

A ray of light came through the high window and fell on the face of the sleeping man. It occurred to the warden for the first time that his prisoner appeared haggard and weary. Just then The Thinking Machine stirred slightly and the warden hurried on up the corridor guiltily. That evening after six o'clock he saw the jailer.

"Everything all right in Cell 13?" he asked. "Yes, sir," replied the jailer. "He didn't eat much, though."

It was with a feeling of having done his duty that the warden received Dr. Ransome and Mr. Fielding shortly after seven o'clock. He intended to show them the linen notes and lay before them the full story of his woes, which was a long one. But before this came to pass the guard from the river side of the prison yard entered the office.

"The arc light in my side of the yard won't light," he informed the warden.

"Confound it, that man's a hoodoo," thundered the official. "Everything has happened since he's been here."

The guard went back to his post in the darkness, and the warden 'phoned to the electric light company.

"This is Chisholm Prison," he said through the 'phone. "Send three or four men down here quick, to fix an arc light."

The reply was evidently satisfactory, for the warden hung up the receiver and passed out into the yard. While Dr. Ransome and Mr. Fielding sat waiting the guard at the outer gate came in with a special delivery letter. Dr. Ransome happened to notice the address, and, when the guard went out, looked at the letter more closely.

"By George!" he exclaimed.

"What is it?" asked Mr. Fielding.

Silently the doctor offered the letter. Mr. Fielding examined it closely.

"Coincidence," he said. "It must be."

It was nearly eight o'clock when the warden returned to his office. The electricians had arrived in a wagon, and were now at work. The warden pressed the buzz-button communicating with the man at the outer gate in the wall.

"How many electricians came in?" he asked, over the short 'phone. "Four? Three workmen in jumpers and overalls and the manager? Frock coat and silk hat? All right. Be certain that only four go out. That's all."

He turned to Dr. Ransome and Mr. Fielding. "We have to be careful here--particularly," and there was broad sarcasm in his tone, "since we have scientists locked up."

The warden picked up the special delivery letter carelessly, and then began to open it.

"When I read this I want to tell you gentlemen something about how---- Great Cæsar!" he ended, suddenly, as he glanced at the letter. He sat with mouth open, motionless, from astonishment.

"What is it?" asked Mr. Fielding.

"A special delivery letter from Cell 13," gasped the warden. "An invitation to supper."

"What?" and the two others arose, unanimously. The warden sat dazed, staring at the letter for a moment, then called sharply to a guard outside in the corridor.

"Run down to Cell 13 and see if that man's in there."

The guard went as directed, while Dr. Ransome and Mr. Fielding examined the letter.

"It's Van Dusen's handwriting; there's no question of that," said Dr. Ransome. "I've seen too much of it."

Just then the buzz of the telephone from the outer gate sounded, and the warden, in a semi-trance, picked up the receiver.

"Hello! Two reporters, eh? Let 'em come in." He turned suddenly to the doctor and Mr. Fielding. "Why, the man _can't_ be out. He must be in his cell."

Just at that moment the guard returned.

"He's still in his cell, sir," he reported. "I saw him. He's lying down."

"There, I told you so," said the warden, and he breathed freely again. "But how did he mail that letter?"

There was a rap on the steel door which led from the jail yard into the warden's office.

"It's the reporters," said the warden. "Let them in," he instructed the guard; then to the two other gentlemen: "Don't say anything about this before them, because I'd never hear the last of it."

The door opened, and the two men from the front gate entered.

"Good-evening, gentlemen," said one. That was Hutchinson Hatch; the warden knew him well.

"Well?" demanded the other, irritably. "I'm here."

That was The Thinking Machine.

He squinted belligerently at the warden, who sat with mouth agape. For the moment that official had nothing to say. Dr. Ransome and Mr. Fielding were amazed, but they didn't know what the warden knew. They were only amazed; he was paralyzed. Hutchinson Hatch, the reporter, took in the scene with greedy eyes.

"How--how--how did you do it?" gasped the warden, finally.

"Come back to the cell," said The Thinking Machine, in the irritated voice which his scientific associates knew so well.

The warden, still in a condition bordering on trance, led the way.

"Flash your light in there," directed The Thinking Machine.

The warden did so. There was nothing unusual in the appearance of the cell, and there--there on the bed lay the figure of The Thinking Machine. Certainly! There was the yellow hair! Again the warden looked at the man beside him and wondered at the strangeness of his own dreams.

With trembling hands he unlocked the cell door and The Thinking Machine passed inside.

"See here," he said.

He kicked at the steel bars in the bottom of the cell door and three of them were pushed out of place. A fourth broke off and rolled away in the corridor.

"And here, too," directed the erstwhile prisoner as he stood on the bed to reach the small window. He swept his hand across the opening and every bar came out.

"What's this in the bed?" demanded the warden, who was slowly recovering.

"A wig," was the reply. "Turn down the cover."

The warden did so. Beneath it lay a large coil of strong rope, thirty feet or more, a dagger, three files, ten feet of electric wire, a thin, powerful pair of steel pliers, a small tack hammer with its handle, and--and a Derringer pistol.

"How did you do it?" demanded the warden.

"You gentlemen have an engagement to supper with me at half-past nine o'clock," said The Thinking Machine. "Come on, or we shall be late."

"But how did you do it?" insisted the warden.

"Don't ever think you can hold any man who can use his brain," said The Thinking Machine. "Come on; we shall be late."

It was an impatient supper party in the rooms of Professor Van Dusen and a somewhat silent one. The guests were Dr. Ransome, Albert Fielding, the warden, and Hutchinson Hatch, reporter. The meal was served to the minute, in accordance with Professor Van Dusen's instructions of one week before; Dr. Ransome found the artichokes delicious. At last the supper was finished and The Thinking Machine turned full on Dr. Ransome and squinted at him fiercely.

"Do you believe it now?" he demanded.

"I do," replied Dr. Ransome.

"Do you admit that it was a fair test?"

"I do."

With the others, particularly the warden, he was waiting anxiously for the explanation.

"Suppose you tell us how----" began Mr. Fielding.

"Yes, tell us how," said the warden.

The Thinking Machine readjusted his glasses, took a couple of preparatory squints at his audience, and began the story. He told it from the beginning logically; and no man ever talked to more interested listeners.

"My agreement was," he began, "to go into a cell, carrying nothing except what was necessary to wear, and to leave that cell within a week. I had never seen Chisholm Prison. When I went into the cell I asked for tooth powder, two ten and one five-dollar bills, and also to have my shoes blacked. Even if these requests had been refused it would not have mattered seriously. But you agreed to them.

"I knew there would be nothing in the cell which you thought I might use to advantage. So when the warden locked the door on me I was apparently helpless, unless I could turn three seemingly innocent things to use. They were things which would have been permitted any prisoner under sentence of death, were they not, warden?"

"Tooth powder and polished shoes, yes, but not money," replied the warden.

"Anything is dangerous in the hands of a man who knows how to use it," went on The Thinking Machine. "I did nothing that first night but sleep and chase rats." He glared at the warden. "When the matter was broached I knew I could do nothing that night, so suggested next day. You gentlemen thought I wanted time to arrange an escape with outside assistance, but this was not true. I knew I could communicate with whom I pleased, when I pleased."

The warden stared at him a moment, then went on smoking solemnly.

"I was aroused next morning at six o'clock by the jailer with my breakfast," continued the scientist. "He told me dinner was at twelve and supper at six. Between these times, I gathered, I would be pretty much to myself. So immediately after breakfast I examined my outside surroundings from my cell window. One look told me it would be useless to try to scale the wall, even should I decide to leave my cell by the window, for my purpose was to leave not only the cell, but the prison. Of course, I could have gone over the wall, but it would have taken me longer to lay my plans that way. Therefore, for the moment, I dismissed all idea of that.

"From this first observation I knew the river was on that side of the prison, and that there was also a playground there. Subsequently these surmises were verified by a keeper. I knew then one important thing--that anyone might approach the prison wall from that side if necessary without attracting any particular attention. That was well to remember. I remembered it.

"But the outside thing which most attracted my attention was the feed wire to the arc light which ran within a few feet--probably three or four--of my cell window. I knew that would be valuable in the event I found it necessary to cut off that arc light."

"Oh, you shut it off to-night, then?" asked the warden.

"Having learned all I could from that window," resumed The Thinking Machine, without heeding the interruption, "I considered the idea of escaping through the prison proper. I recalled just how I had come into the cell, which I knew would be the only way. Seven doors lay between me and the outside. So, also for the time being, I gave up the idea of escaping that way. And I couldn't go through the solid granite walls of the cell."

The Thinking Machine paused for a moment and Dr. Ransome lighted a new cigar. For several minutes there was silence, then the scientific jail-breaker went on:

"While I was thinking about these things a rat ran across my foot. It suggested a new line, of thought. There were at least half a dozen rats in the cell--I could see their beady eyes. Yet I had noticed none come under the cell door. I frightened them purposely and watched the cell door to see if they went out that way. They did not, but they were gone. Obviously they went another way. Another way meant another opening.

"I searched for this opening and found it. It was an old drain pipe, long unused and partly choked with dirt and dust. But this was the way the rats had come. They came from somewhere. Where? Drain pipes usually lead outside prison grounds. This one probably led to the river, or near it. The rats must therefore come from that direction. If they came a part of the way, I reasoned that they came all the way, because it was extremely unlikely that a solid iron or lead pipe would have any hole in it except at the exit.

"When the jailer came with my luncheon he told me two important things, although he didn't know it. One was that a new system of plumbing had been put in the prison seven years before; another that the river was only three hundred feet away. Then I knew positively that the pipe was a part of an old system; I knew, too, that it slanted generally toward the river. But did the pipe end in the water or on land?

"This was the next question to be decided. I decided it by catching several of the rats in the cell. My jailer was surprised to see me engaged in this work. I examined at least a dozen of them. They were perfectly dry; they had come through the pipe, and, most important of all, they were _not house rats, but field rats_. The other end of the pipe was on land, then, outside the prison walls. So far, so good.

"Then, I knew that if I worked freely from this point I must attract the warden's attention in another direction. You see, by telling the warden that I had come there to escape you made the test more severe, because I had to trick him by false scents."

The warden looked up with a sad expression in his eyes.

"The first thing was to make him think I was trying to communicate with you, Dr. Ransome. So I wrote a note on a piece of linen I tore from my shirt, addressed it to Dr. Ransome, tied a five-dollar bill around it and threw it out the window. I knew the guard would take it to the warden, but I rather hoped the warden would send it as addressed. Have you that first linen note, warden?"

The warden produced the cipher.

"What the deuce does it mean, anyhow?" he asked.

"Read it backward, beginning with the 'T' signature and disregard the division into words," instructed The Thinking Machine.

The warden did so.

"T-h-i-s, this," he spelled, studied it a moment, then read it off, grinning:

"This is not the way I intend to escape."

"Well, now what do you think o' that?" he demanded, still grinning.

"I knew that would attract your attention, just as it did," said The Thinking Machine, "and if you really found out what it was it would be a sort of gentle rebuke."

"What did you write it with?" asked Dr. Ransome, after he had examined the linen and passed it to Mr. Fielding.

"This," said the erstwhile prisoner, and he extended his foot. On it was the shoe he had worn in prison, though the polish was gone--scraped off clean. "The shoe blacking, moistened with water, was my ink; the metal tip of the shoe lace made a fairly good pen."

The warden looked up and suddenly burst into a laugh, half of relief, half of amusement.

"You're a wonder," he said, admiringly. "Go on."

"That precipitated a search of my cell by the warden, as I had intended," continued The Thinking Machine. "I was anxious to get the warden into the habit of searching my cell, so that finally, constantly finding nothing, he would get disgusted and quit. This at last happened, practically."

The warden blushed.

"He then took my white shirt away and gave me a prison shirt. He was satisfied that those two pieces of the shirt were all that was missing. But while he was searching my cell I had another piece of that same shirt, about nine inches square, rolled into a small ball in my mouth."

"Nine inches of that shirt?" demanded the warden. "Where did it come from?"

"The bosoms of all stiff white shirts are of triple thickness," was the explanation. "I tore out the inside thickness, leaving the bosom only two thicknesses. I knew you wouldn't see it. So much for that."

There was a little pause, and the warden looked from one to another of the men with a sheepish grin.

"Having disposed of the warden for the time being by giving him something else to think about, I took my first serious step toward freedom," said Professor Van Dusen. "I knew, within reason, that the pipe led somewhere to the playground outside; I knew a great many boys played there; I knew that rats came into my cell from out there. Could I communicate with some one outside with these things at hand?

"First was necessary, I saw, a long and fairly reliable thread, so--but here," he pulled up his trousers legs and showed that the tops of both stockings, of fine, strong lisle, were gone. "I unraveled those--after I got them started it wasn't difficult--and I had easily a quarter of a mile of thread that I could depend on.

"Then on half of my remaining linen I wrote, laboriously enough I assure you, a letter explaining my situation to this gentleman here," and he indicated Hutchinson Hatch. "I knew he would assist me--for the value of the newspaper story. I tied firmly to this linen letter a ten-dollar bill--there is no surer way of attracting the eye of anyone--and wrote on the linen: 'Finder of this deliver to Hutchinson Hatch, _Daily American_, who will give another ten dollars for the information.'

"The next thing was to get this note outside on that playground where a boy might find it. There were two ways, but I chose the best. I took one of the rats--I became adept in catching them--tied the linen and money firmly to one leg, fastened my lisle thread to another, and turned him loose in the drain pipe. I reasoned that the natural fright of the rodent would make him run until he was outside the pipe and then out on earth he would probably stop to gnaw off the linen and money.

"From the moment the rat disappeared into that dusty pipe I became anxious. I was taking so many chances. The rat might gnaw the string, of which I held one end; other rats might gnaw it; the rat might run out of the pipe and leave the linen and money where they would never be found; a thousand other things might have happened. So began some nervous hours, but the fact that the rat ran on until only a few feet of the string remained in my cell made me think he was outside the pipe. I had carefully instructed Mr. Hatch what to do in case the note reached him. The question was: Would it reach him?

"This done, I could only wait and make other plans in case this one failed. I openly attempted to bribe my jailer, and learned from him that he held the keys to only two of seven doors between me and freedom. Then I did something else to make the warden nervous. I took the steel supports out of the heels of my shoes and made a pretense of sawing the bars of my cell window. The warden raised a pretty row about that. He developed, too, the habit of shaking the bars of my cell window to see if they were solid. They were--then."

Again the warden grinned. He had ceased being astonished.

"With this one plan I had done all I could and could only wait to see what happened," the scientist went on. "I couldn't know whether my note had been delivered or even found, or whether the mouse had gnawed it up. And I didn't dare to draw back through the pipe that one slender thread which connected me with the outside.

"When I went to bed that night I didn't sleep, for fear there would come the slight signal twitch at the thread which was to tell me that Mr. Hatch had received the note. At half-past three o'clock, I judge, I felt this twitch, and no prisoner actually under sentence of death ever welcomed a thing more heartily."

The Thinking Machine stopped and turned to the reporter.

"You'd better explain just what you did," he said.

"The linen note was brought to me by a small boy who had been playing baseball," said Mr. Hatch. "I immediately saw a big story in it, so I gave the boy another ten dollars, and got several spools of silk, some twine, and a roll of light, pliable wire. The professor's note suggested that I have the finder of the note show me just where it was picked up, and told me to make my search from there, beginning at two o'clock in the morning. If I found the other end of the thread I was to twitch it gently three times, then a fourth.

"I began the search with a small bulb electric light. It was an hour and twenty minutes before I found the end of the drain pipe, half hidden in weeds. The pipe was very large there, say twelve inches across. Then I found the end of the lisle thread, twitched it as directed and immediately I got an answering twitch.

"Then I fastened the silk to this and Professor Van Dusen began to pull it into his cell. I nearly had heart disease for fear the string would break. To the end of the silk I fastened the twine, and when that had been pulled in I tied on the wire. Then that was drawn into the pipe and we had a substantial line, which rats couldn't gnaw, from the mouth of the drain into the cell."

The Thinking Machine raised his hand and Hatch stopped.

"All this was done in absolute silence," said the scientist. "But when the wire reached my hand I could have shouted. Then we tried another experiment, which Mr. Hatch was prepared for. I tested the pipe as a speaking tube. Neither of us could hear very clearly, but I dared not speak loud for fear of attracting attention in the prison. At last I made him understand what I wanted immediately. He seemed to have great difficulty in understanding when I asked for nitric acid, and I repeated the word 'acid' several times.

"Then I heard a shriek from a cell above me. I knew instantly that some one had overheard, and when I heard you coming, Mr. Warden, I feigned sleep. If you had entered my cell at that moment that whole plan of escape would have ended there. But you passed on. That was the nearest I ever came to being caught.

"Having established this improvised trolley it is easy to see how I got things in the cell and made them disappear at will. I merely dropped them back into the pipe. You, Mr. Warden, could not have reached the connecting wire with your fingers; they are too large. My fingers, you see, are longer and more slender. In addition I guarded the top of that pipe with a rat--you remember how."

"I remember," said the warden, with a grimace. "I thought that if any one were tempted to investigate that hole the rat would dampen his ardor. Mr. Hatch could not send me anything useful through the pipe until next night, although he did send me change for ten dollars as a test, so I proceeded with other parts of my plan. Then I evolved the method of escape, which I finally employed.

"In order to carry this out successfully it was necessary for the guard in the yard to get accustomed to seeing me at the cell window. I arranged this by dropping linen notes to him, boastful in tone, to make the warden believe, if possible, one of his assistants was communicating with the outside for me. I would stand at my window for hours gazing out, so the guard could see, and occasionally I spoke to him. In that way I learned that the prison had no electricians of its own, but was dependent upon the lighting company if anything should go wrong.

"That cleared the way to freedom perfectly: Early in the evening of the last day of my imprisonment, when it was dark, I planned to cut the feed wire which was only a few feet from my window, reaching it with an acid-tipped wire I had. That would make that side of the prison perfectly dark while the electricians were searching for the break. That would also bring Mr. Hatch into the prison yard.

"There was only one more thing to do before I actually began the work of setting myself free. This was to arrange final details with Mr. Hatch through our speaking tube. I did this within half an hour after the warden left my cell on the fourth night of my imprisonment. Mr. Hatch again had serious difficulty in understanding me, and I repeated the word 'acid' to him several times, and later the words: 'Number eight hat'--that's my size--and these were the things which made a prisoner upstairs confess to murder, so one of the jailers told me next day. This prisoner heard our voices, confused of course, through the pipe, which also went to his cell. The cell directly over me was not occupied, hence no one else heard.

"Of course the actual work of cutting the steel bars out of the window and door was comparatively easy with nitric acid, which I got through the pipe in thin bottles, but it took time. Hour after hour on the fifth and sixth and seventh days the guard below was looking at me as I worked on the bars of the window with the acid on a piece of wire. I used the tooth powder to prevent the acid spreading. I looked away abstractedly as I worked and each minute the acid cut deeper into the metal. I noticed that the jailers always tried the door by shaking the upper part, never the lower bars, therefore I cut the lower bars, leaving them hanging in place by thin strips of metal. But that was a bit of dare-deviltry. I could not have gone that way so easily."

The Thinking Machine sat silent for several minutes.

"I think that makes everything clear," he went on. "Whatever points I have not explained were merely to confuse the warden and jailers. These things in my bed I brought in to please Mr. Hatch, who wanted to improve the story. Of course, the wig was necessary in my plan. The special delivery letter I wrote and directed in my cell with Mr. Hatch's fountain pen, then sent it out to him and he mailed it. That's all, I think."

"But your actually leaving the prison grounds and then coming in through the outer gate to my office?" asked the warden.

"Perfectly simple," said the scientist. "I cut the electric light wire with acid, as I said, when the current was off. Therefore when the current was turned on the arc didn't light. I knew it would take some time to find out what was the matter and make repairs. When the guard went to report to you the yard was dark. I crept out the window--it was a tight fit, too--replaced the bars by standing on a narrow ledge and remained in a shadow until the force of electricians arrived. Mr. Hatch was one of them.

"When I saw him I spoke and he handed me a cap, a jumper and overalls, which I put on within ten feet of you, Mr. Warden, while you were in the yard. Later Mr. Hatch called me, presumably as a workman, and together we went out the gate to get something out of the wagon. The gate guard let us pass out readily as two workmen who had just passed in. We changed our clothing and reappeared, asking to see you. We saw you. That's all."

There was silence for several minutes. Dr. Ransome was first to speak.

"Wonderful!" he exclaimed. "Perfectly amazing."

"How did Mr. Hatch happen to come with the electricians?" asked Mr. Fielding.

"His father is manager of the company," replied The Thinking Machine.

"But what if there had been no Mr. Hatch outside to help?"

"Every prisoner has one friend outside who would help him escape if he could."

"Suppose--just suppose--there had been no old plumbing system there?" asked the warden, curiously.

"There were two other ways out," said The Thinking Machine, enigmatically.

Ten minutes later the telephone bell rang. It was a request for the warden.

"Light all right, eh?" the warden asked, through the 'phone. "Good. Wire cut beside Cell 13? Yes, I know. One electrician too many? What's that? Two came out?"

The warden turned to the others with a puzzled expression.

"He only let in four electricians, he has let out two and says there are three left."

"I was the odd one," said The Thinking Machine. "Oh," said the warden. "I see." Then through the 'phone "Let the fifth man go. He's all right."

The Thinking Machine--Professor Augustus S. F. X. Van Dusen, Ph.D., LL.D., F.R.S., M.D., etc., scientist and logician--listened intently and without comment to a weird, seemingly inexplicable story. Hutchinson Hatch, reporter, was telling it. The bowed figure of the savant lay at ease in a large chair. The enormous head with its bushy yellow hair was thrown back, the thin, white fingers were pressed tip to tip and the blue eyes, narrowed to mere slits, squinted aggressively upward. The scientist was in a receptive mood.

"From the beginning, every fact you know," he had requested.

"It's all out in the Back Bay," the reporter explained. "There is a big apartment house there, a fashionable establishment, in a side street, just off Commonwealth Avenue. It is five stories in all, and is cut up into small suites, of two and three rooms with bath. These suites are handsomely, even luxuriously furnished, and are occupied by people who can afford to pay big rents. Generally these are young unmarried men, although in several cases they are husband and wife. It is a house of every modern improvement, elevator service, hall boys, liveried door men, spacious corridors and all that. It has both the gas and electric systems of lighting. Tenants are at liberty to use either or both.

"A young broker, Weldon Henley, occupies one of the handsomest of these suites, being on the second floor, in front. He has met with considerable success in the Street. He is a bachelor and lives there alone. There is no personal servant. He dabbles in photography as a hobby, and is said to be remarkably expert.

"Recently there was a report that he was to be married this Winter to a beautiful Virginia girl who has been visiting Boston from time to time, a Miss Lipscomb--Charlotte Lipscomb, of Richmond. Henley has never denied or affirmed this rumor, although he has been asked about it often. Miss Lipscomb is impossible of access even when she visits Boston. Now she is in Virginia, I understand, but will return to Boston later in the season."

The reporter paused, lighted a cigarette and leaned forward in his chair, gazing steadily into the inscrutable eyes of the scientist.

"When Henley took the suite he requested that all the electric lighting apparatus be removed from his apartments," he went on. "He had taken a long lease of the place, and this was done. Therefore he uses only gas for lighting purposes, and he usually keeps one of his gas jets burning low all night."

"Bad, bad for his health," commented the scientist.

"Now comes the mystery of the affair," the reporter went on. "It was five weeks or so ago Henley retired as usual--about midnight. He locked his door on the inside--he is positive of that--and awoke about four o'clock in the morning nearly asphyxiated by gas. He was barely able to get up and open the window to let in the fresh air. The gas jet he had left burning was out, and the suite was full of gas."

"Accident, possibly," said The Thinking Machine. "A draught through the apartments; a slight diminution of gas pressure; a hundred possibilities."

"So it was presumed," said the reporter. "Of course it would have been impossible for----"

"Nothing is impossible," said the other, tartly. "Don't say that. It annoys me exceedingly."

"Well, then, it seems highly improbable that the door had been opened or that anyone came into the room and did this deliberately," the newspaper man went on, with a slight smile. "So Henley said nothing about this; attributed it to accident. The next night he lighted his gas as usual, but he left it burning a little brighter. The same thing happened again."

"Ah," and The Thinking Machine changed his position a little. "The second time."

"And again he awoke just in time to save himself," said Hatch. "Still he attributed the affair to accident, and determined to avoid a recurrence of the affair by doing away with the gas at night. Then he got a small night lamp and used this for a week or more."

"Why does he have a light at all?" asked the scientist, testily.

"I can hardly answer that," replied Hatch. "I may say, however, that he is of a very nervous temperament, and gets up frequently during the night. He reads occasionally when he can't sleep. In addition to that he has slept with a light going all his life; it's a habit."

"Go on."

"One night he looked for the night lamp, but it had disappeared--at least he couldn't find it--so he lighted the gas again. The fact of the gas having twice before gone out had been dismissed as a serious possibility. Next morning at five o'clock a bell boy, passing through the hall, smelled gas and made a quick investigation. He decided it came from Henley's place, and rapped on the door. There was no answer. It ultimately developed that it was necessary to smash in the door. There on the bed they found Henley unconscious with the gas pouring into the room from the jet which he had left lighted. He was revived in the air, but for several hours was deathly sick."

"Why was the door smashed in?" asked The Thinking Machine. "Why not unlocked?"

"It was done because Henley had firmly barred it," Hatch explained. "He had become suspicious, I suppose, and after the second time he always barred his door and fastened every window before he went to sleep. There may have been a fear that some one used a key to enter."

"Well?" asked the scientist. "After that?"

"Three weeks or so elapsed, bringing the affair down to this morning," Hatch went on. "Then the same thing happened a little differently. For instance, after the third time the gas went out Henley decided to find out for himself what caused it, and so expressed himself to a few friends who knew of the mystery. Then, night after night, he lighted the gas as usual and kept watch. It was never disturbed during all that time, burning steadily all night. What sleep he got was in daytime.

"Last night Henley lay awake for a time; then, exhausted and tired, fell asleep. This morning early he awoke; the room was filled with gas again. In some way my city editor heard of it and asked me to look into the mystery."

That was all. The two men were silent for a long time, and finally The Thinking Machine turned to the reporter.

"Does anyone else in the house keep gas going all night?" he asked.

"I don't know," was the reply. "Most of them, I know, use electricity."

"Nobody else has been overcome as he has been?"

"No. Plumbers have minutely examined the lighting system all over the house and found nothing wrong."

"Does the gas in the house all come through the same meter?"

"Yes, so the manager told me. This meter, a big one, is just off the engine room. I supposed it possible that some one shut it off there on these nights long enough to extinguish the lights all over the house, then turned it on again. That is, presuming that it was done purposely. Do you think it was an attempt to kill Henley?"

"It might be," was the reply. "Find out for me just who in the house uses gas; also if anyone else leaves a light burning all night; also what opportunity anyone would have to get at the meter, and then something about Henley's love affair with Miss Lipscomb. Is there anyone else? If so, who? Where does he live? When you find out these things come back here."

* * * * *

That afternoon at one o'clock Hatch returned to the apartments of The Thinking Machine, with excitement plainly apparent on his face.

"Well?" asked the scientist.

"A French girl, Louise Regnier, employed as a maid by Mrs. Standing in the house, was found dead in her room on the third floor to-day at noon," Hatch explained quickly. "It looks like suicide."

"How?" asked The Thinking Machine.

"The people who employed her--husband and wife--have been away for a couple of days," Hatch rushed on. "She was in the suite alone. This noon she had not appeared, there was an odor of gas and the door was broken in. Then she was found dead."

"With the gas turned on?"

"With the gas turned on. She was asphyxiated."

"Dear me, dear me," exclaimed the scientist. He arose and took up his hat. "Let's go see what this is all about."

When Professor Van Dusen and Hatch arrived at the apartment house they had been preceded by the Medical Examiner and the police. Detective Mallory, whom both knew, was moving about in the apartment where the girl had been found dead. The body had been removed and a telegram sent to her employers in New York.

"Too late," said Mallory, as they entered.

"What was it, Mr. Mallory?" asked the scientist.

"Suicide," was the reply. "No question of it. It happened in this room," and he led the way into the third room of the suite. "The maid, Miss Regnier, occupied this, and was here alone last night. Mr. and Mrs. Standing, her employers, have gone to New York for a few days. She was left alone, and killed herself."

Without further questioning The Thinking Machine went over to the bed, from which the girl's body had been taken, and, stooping beside it, picked up a book. It was a novel by "The Duchess." He examined this critically, then, standing on a chair, he examined the gas jet. This done, he stepped down and went to the window of the little room. Finally The Thinking Machine turned to the detective.

"Just how much was the gas turned on?" he asked.

"Turned on full," was the reply.

"Were both the doors of the room closed?"

"Both, yes."

"Any cotton, or cloth, or anything of the sort stuffed in the cracks of the window?"

"No. It's a tight-fitting window, anyway. Are you trying to make a mystery out of this?"

"Cracks in the doors stuffed?" The Thinking Machine went on.

"No." There was a smile about the detective's lips.

The Thinking Machine, on his knees, examined the bottom of one of the doors, that which led into the hall. The lock of this door had been broken when employees burst into the room. Having satisfied himself here and at the bottom of the other door, which connected with the bedroom adjoining, The Thinking Machine again climbed on a chair and examined the doors at the top.

"Both transoms closed, I suppose?" he asked. "Yes," was the reply. "You can't make anything but suicide out of it," explained the detective. "The Medical Examiner has given that as his opinion--and everything I find indicates it."

"All right," broke in The Thinking Machine abruptly. "Don't let us keep you."

After awhile Detective Mallory went away. Hatch and the scientist went down to the office floor, where they saw the manager. He seemed to be greatly distressed, but was willing to do anything he could in the matter.

"Is your night engineer perfectly trustworthy?" asked The Thinking Machine.

"Perfectly," was the reply. "One of the best and most reliable men I ever met. Alert and wide-awake."

"Can I see him a moment? The night man, I mean?"

"Certainly," was the reply. "He's downstairs. He sleeps there. He's probably up by this time. He sleeps usually till one o'clock in the daytime, being up all night."

"Do you supply gas for your tenants?"

"Both gas and electricity are included in the rent of the suites. Tenants may use one or both."

"And the gas all comes through one meter?"

"Yes, one meter. It's just off the engine room."

"I suppose there's no way of telling just who in the house uses gas?"

"No. Some do and some don't. I don't know."

This was what Hatch had told the scientist. Now together they went to the basement, and there met the night engineer, Charles Burlingame, a tall, powerful, clean-cut man, of alert manner and positive speech. He gazed with a little amusement at the slender, almost childish figure of The Thinking Machine and the grotesquely large head.

"You are in the engine room or near it all night every night?" began The Thinking Machine.

"I haven't missed a night in four years," was the reply.

"Anybody ever come here to see you at night?"

"Never. It's against the rules."

"The manager or a hall boy?"

"Never."

"In the last two months?" The Thinking Machine persisted.

"Not in the last two years," was the positive reply. "I go on duty every night at seven o'clock, and I am on duty until seven in the morning. I don't believe I've seen anybody in the basement here with me between those hours for a year at least."

The Thinking Machine was squinting steadily into the eyes of the engineer, and for a time both were silent. Hatch moved about the scrupulously clean engine room and nodded to the day engineer, who sat leaning back against the wall. Directly in front of him was the steam gauge.

"Have you a fireman?" was The Thinking Machine's next question.

"No. I fire myself," said the night man. "Here's the coal," and he indicated a bin within half a dozen feet of the mouth of the boiler.

"I don't suppose you ever had occasion to handle the gas meter?" insisted The Thinking Machine.

"Never touched it in my life," said the other. "I don't know anything about meters, anyway."

"And you never drop off to sleep at night for a few minutes when you get lonely? Doze, I mean?"

The engineer grinned good-naturedly.

"Never had any desire to, and besides I wouldn't have the chance," he explained. "There's a time check here,"--and he indicated it. "I have to punch that every half hour all night to prove that I have been awake."

"Dear me, dear me," exclaimed The Thinking Machine, irritably. He went over and examined the time check--a revolving paper disk with hours marked on it, made to move by the action of a clock, the face of which showed in the middle.

"Besides there's the steam gauge to watch," went on the engineer. "No engineer would dare go to sleep. There might be an explosion."

"Do you know Mr. Weldon Henley?" suddenly asked The Thinking Machine.

"Who?" asked Burlingame.

"Weldon Henley?"

"No-o," was the slow response. "Never heard of him. Who is he?"

"One of the tenants, on the second floor, I think."

"Lord, I don't know any of the tenants. What about him?"

"When does the inspector come here to read the meter?"

"I never saw him. I presume in daytime, eh Bill?" and he turned to the day engineer.

"Always in daytime--usually about noon," said Bill from his corner.

"Any other entrance to the basement except this way--and you could see anyone coming here this way I suppose?"

"Sure I could see 'em. There's no other entrance to the cellar except the coal hole in the sidewalk in front."

"Two big electric lights in front of the building, aren't there?"

"Yes. They go all night."

A slightly puzzled expression crept into the eyes of The Thinking Machine. Hatch knew from the persistency of the questions that he was not satisfied; yet he was not able to fathom or to understand all the queries. In some way they had to do with the possibility of some one having access to the meter.

"Where do you usually sit at night here?" was the next question.

"Over there where Bill's sitting. I always sit there."

The Thinking Machine crossed the room to Bill, a typical, grimy-handed man of his class.

"May I sit there a moment?" he asked.

Bill arose lazily, and The Thinking Machine sank down into the chair. From this point he could see plainly through the opening into the basement proper--there was no door--the gas meter of enormous proportions through which all the gas in the house passed. An electric light in the door made it bright as daylight. The Thinking Machine noted these things, arose, nodded his thanks to the two men and, still with the puzzled expression on his face, led the way upstairs. There the manager was still in his office.

"I presume you examine and know that the time check in the engineer's room is properly punched every half-hour during the night?" he asked.

"Yes. I examine the dial every day--have them here, in fact, each with the date on it."

"May I see them?"

Now the manager was puzzled. He produced the cards, one for each day, and for half an hour The Thinking Machine studied them minutely. At the end of that time, when he arose and Hatch looked at him inquiringly, he saw still the perplexed expression.

After urgent solicitation, the manager admitted them to the apartments of Weldon Henley. Mr. Henley himself had gone to his office in State Street. Here The Thinking Machine did several things which aroused the curiosity of the manager, one of which was to minutely study the gas jets. Then The Thinking Machine opened one of the front windows and glanced out into the street. Below fifteen feet was the sidewalk; above was the solid front of the building, broken only by a flagpole which, properly roped, extended from the hall window of the next floor above out over the sidewalk a distance of twelve feet or so.

"Ever use that flagpole?" he asked the manager.

"Rarely," said the manager. "On holidays sometimes--Fourth of July and such times. We have a big flag for it."

From the apartments The Thinking Machine led the way to the hall, up the stairs and to the flagpole. Leaning out of this window, he looked down toward the window of the apartments he had just left. Then he inspected the rope of the flagpole, drawing it through his slender hands slowly and carefully. At last he picked off a slender thread of scarlet and examined it.

"Ah," he exclaimed. Then to Hatch: "Let's go, Mr. Hatch. Thank you," this last to the manager, who had been a puzzled witness.

Once on the street, side by side with The Thinking Machine, Hatch was bursting with questions, but he didn't ask them. He knew it would be useless. At last The Thinking Machine broke the silence.

"That girl, Miss Regnier, _was murdered_," he said suddenly, positively. "There have been four attempts to murder Henley."

"How?" asked Hatch, startled.

"By a scheme so simple that neither you nor I nor the police have ever heard of it being employed," was the astonishing reply. "_It is perfectly horrible in its simplicity_."

"What was it?" Hatch insisted, eagerly.

"It would be futile to discuss that now," was the rejoinder. "There has been murder. We know how. Now the question is--who? What person would have a motive to kill Henley?"

There was a pause as they walked on.

"Where are we going?" asked Hatch finally.

"Come up to my place and let's consider this matter a bit further," replied The Thinking Machine.

Not another word was spoken by either until half an hour later, in the small laboratory. For a long time the scientist was thoughtful--deeply thoughtful. Once he took down a volume from a shelf and Hatch glanced at the title. It was "Gases: Their Properties." After awhile he returned this to the shelf and took down another, on which the reporter caught the title, "Anatomy."

"Now, Mr. Hatch," said The Thinking Machine in his perpetually crabbed voice, "we have a most remarkable riddle. It gains this remarkable aspect from its very simplicity. It is not, however, necessary to go into that now. I will make it clear to you when we know the motives.

"As a general rule, the greatest crimes never come to light because the greatest criminals, their perpetrators, are too clever to be caught. Here we have what I might call a great crime committed with a subtle simplicity that is wholly disarming, and a greater crime even than this was planned. This was to murder Weldon Henley. The first thing for you to do is to see Mr. Henley and warn him of his danger. Asphyxiation will not be attempted again, but there is a possibility of poison, a pistol shot, a knife, anything almost. As a matter of fact, he is in great peril.

"Superficially, the death of Miss Regnier, the maid, looks to be suicide. Instead it is the fruition of a plan which has been tried time and again against Henley. There is a possibility that Miss Regnier was not an intentional victim of the plot, but the fact remains that she was murdered. Why? Find the motive for the plot to murder Mr. Henley and you will know why."

The Thinking Machine reached over to the shelf, took a book, looked at it a moment, then went on:

"The first question to determine positively is: Who hated Weldon Henley sufficiently to desire his death? You say he is a successful man in the Street. Therefore there is a possibility that some enemy there is at the bottom of the affair, yet it seems hardly probable. If by his operations Mr. Henley ever happened to wreck another man's fortune find this man and find out all about him. He may be the man. There will be innumerable questions arising from this line of inquiry to a man of your resources. Leave none of them unanswered.

"On the other hand there is Henley's love affair. Had he a rival who might desire his death? Had he any rival? If so, find out all about him. He may be the man who planned all this. Here, too, there will be questions arising which demand answers. Answer them--all of them--fully and clearly before you see me again.

"Was Henley ever a party to a liaison of any kind? Find that out, too. A vengeful woman or a discarded sweetheart of a vengeful woman, you know, will go to any extreme. The rumor of his engagement to Miss--Miss----"

"Miss Lipscomb," Hatch supplied.

"The rumor of his engagement to Miss Lipscomb might have caused a woman whom he had once been interested in or who was once interested in him to attempt his life. The subtler murders--that is, the ones which are most attractive as problems--are nearly always the work of a cunning woman. I know nothing about women myself," he hastened to explain; "but Lombroso has taken that attitude. Therefore, see if there is a woman."

Most of these points Hatch had previously seen--seen with the unerring eye of a clever newspaper reporter--yet there were several which had not occurred to him. He nodded his understanding.

"Now the center of the affair, of course," The Thinking Machine continued, "is the apartment house where Henley lives. The person who attempted his life either lives there or has ready access to the place, and frequently spends the night there. This is a vital question for you to answer. I am leaving all this to you because you know better how to do these things than I do. That's all, I think. When these things are all learned come back to me."

The Thinking Machine arose as if the interview were at an end, and Hatch also arose, reluctantly. An idea was beginning to dawn in his mind.

"Does it occur to you that there is any connection whatever between Henley and Miss Regnier?" he asked.

"It is possible," was the reply. "I had thought of that. If there is a connection it is not apparent yet."

"Then how--how was it she--she was killed, or killed herself, whichever may be true, and----"

"The attempt to kill Henley killed her. That's all I can say now."

"That all?" asked Hatch, after a pause.

"No. Warn Mr. Henley immediately that he is in grave danger. Remember the person who has planned this will probably go to any extreme. I don't know Mr. Henley, of course, but from the fact that he always had a light at night I gather that he is a timid sort of man--not necessarily a coward, but a man lacking in stamina--therefore, one who might better disappear for a week or so until the mystery is cleared up. Above all, impress upon him the importance of the warning."

The Thinking Machine opened his pocketbook and took from it the scarlet thread which he had picked from the rope of the flagpole.

"Here, I believe, is the real clew to the problem," he explained to Hatch. "What does it seem to be?"

Hatch examined it closely.

"I should say a strand from a Turkish bath robe," was his final judgment.

"Possibly. Ask some cloth expert what he makes of it, then if it sounds promising look into it. Find out if by any possibility it can be any part of any garment worn by any person in the apartment house."

"But it's so slight----" Hatch began.

"I know," the other interrupted, tartly. "It's slight, but I believe it is a part of the wearing apparel of the person, man or woman, who has four times attempted to kill Mr. Henley and who did kill the girl. Therefore, it is important."

Hatch looked at him quickly.

"Well, how--in what manner--did it come where you found it?"

"Simple enough," said the scientist. "It is a wonder that there were not more pieces of it--that's all."

Perplexed by his instructions, but confident of results, Hatch left The Thinking Machine. What possible connection could this tiny bit of scarlet thread, found on a flagpole, have with some one shutting off the gas in Henley's rooms? How did any one go into Henley's rooms to shut off the gas? How was it Miss Regnier was dead? What was the manner of her death?

A cloth expert in a great department store turned his knowledge on the tiny bit of scarlet for the illumination of Hatch, but he could go no further than to say that it seemed to be part of a Turkish bath robe.

"Man or woman's?" asked Hatch.

"The material from which bath robes are made is the same for both men and women," was the reply. "I can say nothing else. Of course there's not enough of it to even guess at the pattern of the robe."

Then Hatch went to the financial district and was ushered into the office of Weldon Henley, a slender, handsome man of thirty-two or three years, pallid of face and nervous in manner. He still showed the effect of the gas poisoning, and there was even a trace of a furtive fear--fear of something, he himself didn't know what--in his actions.

Henley talked freely to the newspaper man of certain things, but of other things was resentfully reticent. He admitted his engagement to Miss Lipscomb, and finally even admitted that Miss Lipscomb's hand had been sought by another man, Regnault Cabell, formerly of Virginia.

"Could you give me his address?" asked Hatch.

"He lives in the same apartment house with me--two floors above," was the reply.

Hatch was startled; startled more than he would have cared to admit.

"Are you on friendly terms with him?" he asked.

"Certainly," said Henley. "I won't say anything further about this matter. It would be unwise for obvious reasons."

"I suppose you consider that this turning on of the gas was an attempt on your life?"

"I can't suppose anything else."

Hatch studied the pallid face closely as he asked the next question.

"Do you know Miss Regnier was found dead to-day?"

"Dead?" exclaimed the other, and he arose. "Who--what--who is she?"

It seemed a distinct effort for him to regain control of himself.

The reporter detailed then the circumstances of the finding of the girl's body, and the broker listened without comment. From that time forward all the reporter's questions were either parried or else met with a flat refusal to answer. Finally Hatch repeated to him the warning which he had from The Thinking Machine, and feeling that he had accomplished little, went away.

At eight o'clock that night--a night of complete darkness--Henley was found unconscious, lying in a little used walk in the Common. There was a bullet hole through his left shoulder, and he was bleeding profusely. He was removed to the hospital, where he regained consciousness for just a moment.

"Who shot you?" he was asked.

"None of your business," he replied, and lapsed into unconsciousness.

Entirely unaware of this latest attempt on the life of the broker, Hutchinson Hatch steadily pursued his investigations. They finally led him to an intimate friend of Regnault Cabell. The young Southerner had apartments on the fourth floor of the big house off Commonwealth Avenue, directly over those Henley occupied, but two flights higher up. This friend was a figure in the social set of the Back Bay. He talked to Hatch freely of Cabell.

"He's a good fellow," he explained, "one of the best I ever met, and comes of one of the best families Virginia ever had--a true F. F. V. He's pretty quick tempered and all that, but an excellent chap, and everywhere he has gone here he has made friends."

"He used to be in love with Miss Lipscomb of Virginia, didn't he?" asked Hatch, casually.

"Used to be?" the other repeated with a laugh. "He is in love with her. But recently he understood that she was engaged to Weldon Henley, a broker--you may have heard of him?--and that, I suppose, has dampened his ardor considerably. As a matter of fact, Cabell took the thing to heart. He used to know Miss Lipscomb in Virginia--she comes from another famous family there--and he seemed to think he had a prior claim on her."

Hatch heard all these things as any man might listen to gossip, but each additional fact was sinking into his mind, and each additional fact led his suspicions on deeper into the channel they had chosen.

"Cabell is pretty well to do," his informant went on, "not rich as we count riches in the North, but pretty well to do, and I believe he came to Boston because Miss Lipscomb spent so much of her time here. She is a beautiful young woman of twenty-two and extremely popular in the social world everywhere, particularly in Boston. Then there was the additional fact that Henley was here."

"No chance at all for Cabell?" Hatch suggested.

"Not the slightest," was the reply. "Yet despite the heartbreak he had, he was the first to congratulate Henley on winning her love. And he meant it, too."

"What's his attitude toward Henley now?" asked Hatch. His voice was calm, but there was an underlying tense note imperceptible to the other.

"They meet and speak and move in the same set. There's no love lost on either side, I don't suppose, but there is no trace of any ill feeling."

"Cabell doesn't happen to be a vindictive sort of man?"

"Vindictive?" and the other laughed. "No. He's like a big boy, forgiving, and all that; hot-tempered, though. I could imagine him in a fit of anger making a personal matter of it with Henley, but I don't think he ever did."

The mind of the newspaper man was rapidly focusing on one point; the rush of thoughts, questions and doubts silenced him for a moment. Then:

"How long has Cabell been in Boston?"

"Seven or eight months--that is, he has had apartments here for that long--but he has made several visits South. I suppose it's South. He has a trick of dropping out of sight occasionally. I understand that he intends to go South for good very soon. If I'm not mistaken, he is trying now to rent his suite."

Hatch looked suddenly at his informant; an idea of seeing Cabell and having a legitimate excuse for talking to him had occurred to him.

"I'm looking for a suite," he volunteered at last. "I wonder if you would give me a card of introduction to him? We might get together on it."

Thus it happened that half an hour later, about ten minutes past nine o'clock, Hatch was on his way to the big apartment house. In the office he saw the manager.

"Heard the news?" asked the manager.

"No," Hatch replied. "What is it?"

"Somebody's shot Mr. Henley as he was passing through the Common early to-night."

Hatch whistled his amazement.

"Is he dead?"

"No, but he is unconscious. The hospital doctors say it is a nasty wound, but not necessarily dangerous."

"Who shot him? Do they know?"

"He knows, but he won't say."

Amazed and alarmed by this latest development, an accurate fulfillment of The Thinking Machine's prophecy, Hatch stood thoughtful for a moment, then recovering his composure a little asked for Cabell.

"I don't think there's much chance of seeing him," said the manager. "He's going away on the midnight train--going South, to Virginia."

"Going away to-night?" Hatch gasped.

"Yes; it seems to have been rather a sudden determination. He was talking to me here half an hour or so ago, and said something about going away. While he was here the telephone boy told me that Henley had been shot; they had 'phoned from the hospital to inform us. Then Cabell seemed greatly agitated. He said he was going away to-night, if he could catch the midnight train, and now he's packing."

"I suppose the shooting of Henley upset him considerably?" the reporter suggested.

"Yes, I guess it did," was the reply. "They moved in the same set and belonged to the same clubs."

The manager sent Hatch's card of introduction to Cabell's apartments. Hatch went up and was ushered into a suite identical with that of Henley's in every respect save in minor details of furnishings. Cabell stood in the middle of the floor, with his personal belongings scattered about the room; his valet, evidently a Frenchman, was busily engaged in packing.

Cabell's greeting was perfunctorily cordial; he seemed agitated. His face was flushed and from time to time he ran his fingers through his long, brown hair. He stared at Hatch in a preoccupied fashion, then they fell into conversation about the rent of the apartments.

"I'll take almost anything reasonable," Cabell said hurriedly. "You see, I am going away to-night, rather more suddenly than I had intended, and I am anxious to get the lease off my hands. I pay two hundred dollars a month for these just as they are."

"May I look them over?" asked Hatch.

He passed from the front room into the next. Here, on a bed, was piled a huge lot of clothing, and the valet, with deft fingers, was brushing and folding, preparatory to packing. Cabell was directly behind him.

"Quite comfortable, you see," he explained. "There's room enough if you are alone. Are you?"

"Oh, yes," Hatch replied.

"This other room here," Cabell explained, "is not in very tidy shape now. I have been out of the city for several weeks, and---- What's the matter?" he demanded suddenly.

Hatch had turned quickly at the words and stared at him, then recovered himself with a start.

"I beg your pardon," he stammered. "I rather thought I saw you in town here a week or so ago--of course I didn't know you--and I was wondering if I could have been mistaken."

"Must have been," said the other easily. "During the time I was away a Miss----, a friend of my sister's, occupied the suite. I'm afraid some of her things are here. She hasn't sent for them as yet. She occupied this room, I think; when I came back a few days ago she took another place and all her things haven't been removed."

"I see," remarked Hatch, casually. "I don't suppose there's any chance of her returning here unexpectedly if I should happen to take her apartments?"

"Not the slightest. She knows I am back, and thinks I am to remain. She was to send for these things."

Hatch gazed about the room ostentatiously. Across a trunk lay a Turkish bath robe with a scarlet stripe in it. He was anxious to get hold of it, to examine it closely. But he didn't dare to, then. Together they returned to the front room.

"I rather like the place," he said, after a pause, "but the price is----"

"Just a moment," Cabell interrupted. "Jean, before you finish packing that suit case be sure to put my bath robe in it. It's in the far room."

Then one question was settled for Hatch. After a moment the valet returned with the bath robe, which had been in the far room. It was Cabell's bath robe. As Jean passed the reporter an end of the robe caught on a corner of the trunk, and, stopping, the reporter unfastened it. A tiny strand of thread clung to the metal; Hatch detached it and stood idly twirling it in his fingers.

"As I was saying," he resumed, "I rather like the place, but the price is too much. Suppose you leave it in the hands of the manager of the house----"

"I had intended doing that," the Southerner interrupted.

"Well, I'll see him about it later," Hatch added.

With a cordial, albeit preoccupied, handshake, Cabell ushered him out. Hatch went down in the elevator with a feeling of elation; a feeling that he had accomplished something. The manager was waiting to get into the lift.

"Do you happen to remember the name of the young lady who occupied Mr. Cabell's suite while he was away?" he asked.

"Miss Austin," said the manager, "but she's not young. She was about forty-five years old, I should judge."

"Did Mr. Cabell have his servant Jean with him?"

"Oh, no," said the manager. "The valet gave up the suite to Miss Austin entirely, and until Mr. Cabell returned occupied a room in the quarters we have for our own employees."

"Was Miss Austin ailing any way?" asked Hatch. "I saw a large number of medicine bottles upstairs."

"I don't know what was the matter with her," replied the manager, with a little puzzled frown. "She certainly was not a woman of sound mental balance--that is, she was eccentric, and all that. I think rather it was an act of charity for Mr. Cabell to let her have the suite in his absence. Certainly we didn't want her."

Hatch passed out and burst in eagerly upon The Thinking Machine in his laboratory.

"Here," he said, and triumphantly he extended the tiny scarlet strand which he had received from The Thinking Machine, and the other of the identical color which came from Cabell's bath robe. "Is that the same?"

The Thinking Machine placed them under the microscope and examined them immediately. Later he submitted them to a chemical test.

"_It is the same_," he said, finally.

"Then the mystery is solved," said Hatch, conclusively.

The Thinking Machine stared steadily into the eager, exultant eyes of the newspaper man until Hatch at last began to fear that he had been precipitate. After awhile, under close scrutiny, the reporter began to feel convinced that he had made a mistake--he didn't quite see where, but it must be there, and the exultant manner passed. The voice of The Thinking Machine was like a cold shower.

"Remember, Mr. Hatch," he said, critically, "that unless every possible question has been considered one cannot boast of a solution. Is there any possible question lingering yet in your mind?"

The reporter silently considered that for a moment, then:

"Well, I have the main facts, anyway. There may be one or two minor questions left, but the principal ones are answered."

"Then tell me, to the minutest detail, what you have learned, what has happened."

Professor Van Dusen sank back in his old, familiar pose in the large arm chair and Hatch related what he had learned and what he surmised. He related, too, the peculiar circumstances surrounding the wounding of Henley, and right on down to the beginning and end of the interview with Cabell in the latter's apartments. The Thinking Machine was silent for a time, then there came a host of questions.

"Do you know where the woman--Miss Austin--is now?" was the first.

"No," Hatch had to admit.

"Or her precise mental condition?"

"No."

"Or her exact relationship to Cabell?"

"No."

"Do you know, then, what the valet, Jean, knows of the affair?"

"No, not that," said the reporter, and his face flushed under the close questioning. "He was out of the suite every night."

"Therefore might have been the very one who turned on the gas," the other put in testily.

"So far as I can learn, nobody could have gone into that room and turned on the gas," said the reporter, somewhat aggressively. "Henley barred the doors and windows and kept watch, night after night."

"Yet the moment he was exhausted and fell asleep the gas was turned on to kill him," said The Thinking Machine; "thus we see that _he was watched more closely than he watched_."

"I see what you mean now," said Hatch, after a long pause.

"I should like to know what Henley and Cabell and the valet knew of the girl who was found dead," The Thinking Machine suggested. "Further, I should like to know if there was a good-sized mirror--not one set in a bureau or dresser--either in Henley's room or the apartments where the girl was found. Find out this for me and--never mind. I'll go with you."

The scientist left the room. When he returned he wore his coat and hat. Hatch arose mechanically to follow. For a block or more they walked along, neither speaking. The Thinking Machine was the first to break the silence:

"You believe Cabell is the man who attempted to kill Henley?"

"Frankly, yes," replied the newspaper man.

"Why?"

"Because he had the motive--disappointed love."

"How?"

"I don't know," Hatch confessed. "The doors of the Henley suite were closed. I don't see how anybody passed them."

"And the girl? Who killed her? How? Why?"

Disconsolately Hatch shook his head as he walked on. The Thinking Machine interpreted his silence aright.

"Don't jump at conclusions," he advised sharply. "You are confident Cabell was to blame for this--and he might have been, I don't know yet--but you can suggest nothing to show how he did it. I have told you before that imagination is half of logic."

At last the lights of the big apartment house where Henley lived came in sight. Hatch shrugged his shoulders. He had grave doubts--based on what he knew--whether The Thinking Machine would be able to see Cabell. It was nearly eleven o'clock and Cabell was to leave for the South at midnight.

"Is Mr. Cabell here?" asked the scientist of the elevator boy.

"Yes, just about to go, though. He won't see anyone."

"Hand him this note," instructed The Thinking Machine, and he scribbled something on a piece of paper. "He'll see us."

The boy took the paper and the elevator shot up to the fourth floor. After awhile he returned.

"He'll see you," he said.

"Is he unpacking?"

"After he read your note twice he told his valet to unpack," the boy replied.

"Ah, I thought so," said The Thinking Machine.

With Hatch, mystified and puzzled, following, The Thinking Machine entered the elevator to step out a second or so later on the fourth floor. As they left the car they saw the door of Cabell's apartment standing open; Cabell was in the door. Hatch traced a glimmer of anxiety in the eyes of the young man.

"Professor Van Dusen?" Cabell inquired.

"Yes," said the scientist. "It was of the utmost importance that I should see you, otherwise I should not have come at this time of night."

With a wave of his hand Cabell passed that detail. "I was anxious to get away at midnight," he explained, "but, of course, now I shan't go, in view of your note. I have ordered my valet to unpack my things, at least until to-morrow."

The reporter and the scientist passed into the luxuriously furnished apartments. Jean, the valet, was bending over a suit case as they entered, removing some things he had been carefully placing there. He didn't look back or pay the least attention to the visitors.

"This is your valet?" asked The Thinking Machine.

"Yes," said the young man.

"French, isn't he?"

"Yes."

"Speak English at all?"

"Very badly," said Cabell. "I use French when I talk to him."

"Does he know that you are accused of murder?" asked The Thinking Machine, in a quiet, conversational tone.

The effect of the remark on Cabell was startling. He staggered back a step or so as if he had been struck in the face, and a crimson flush overspread his brow. Jean, the valet, straightened up suddenly and looked around. There was a queer expression, too, in his eyes; an expression which Hatch could not fathom.

"Murder?" gasped Cabell, at last.

"Yes, he speaks English all right," remarked The Thinking Machine. "Now, Mr. Cabell, will you please tell me just who Miss Austin is, and where she is, and her mental condition? Believe me, it may save you a great deal of trouble. What I said in the note is not exaggerated."

The young man turned suddenly and began to pace back and forth across the room. After a few minutes he paused before The Thinking Machine, who stood impatiently waiting for an answer.

"I'll tell you, yes," said Cabell, firmly. "Miss Austin is a middle-aged woman whom my sister befriended several times--was, in fact, my sister's governess when she was a child. Of late years she has not been wholly right mentally, and has suffered a great deal of privation. I had about concluded arrangements to put her in a private sanitarium. I permitted her to remain in these rooms in my absence, South. I did not take Jean--he lived in the quarters of the other employees of the place, and gave the apartment entirely to Miss Austin. It was simply an act of charity."

"What was the cause of your sudden determination to go South to-night?" asked the scientist.

"I won't answer that question," was the sullen reply.

There was a long, tense silence. Jean, the valet, came and went several times.

"How long has Miss Austin known Mr. Henley?"

"Presumably since she has been in these apartments," was the reply.

"Are you sure _you_ are not Miss Austin?" demanded the scientist.

The question was almost staggering, not only to Cabell, but to Hatch. Suddenly, with flaming face, the young Southerner leaped forward as if to strike down The Thinking Machine.

"That won't do any good," said the scientist, coldly. "Are you sure you are not Miss Austin?" he repeated.

"Certainly I am not Miss Austin," responded Cabell, fiercely.

"Have you a mirror in these apartments about twelve inches by twelve inches?" asked The Thinking Machine, irrelevantly.

"I--I don't know," stammered the young man. "I--have we, Jean?"

"_Oui_," replied the valet.

"Yes," snapped The Thinking Machine. "Talk English, please. May I see it?"

The valet, without a word but with a sullen glance at the questioner, turned and left the room. He returned after a moment with the mirror. The Thinking Machine carefully examined the frame, top and bottom and on both sides. At last he looked up; again the valet was bending over a suit case.

"Do you use gas in these apartments?" the scientist asked suddenly.

"No," was the bewildered response. "What is all this, anyway?"

Without answering, The Thinking Machine drew a chair up under the chandelier where the gas and electric fixtures were and began to finger the gas tips. After awhile he climbed down and passed into the next room, with Hatch and Cabell, both hopelessly mystified, following. There the scientist went through the same process of fingering the gas jets. Finally, one of the gas tips came out in his hand.

"Ah," he exclaimed, suddenly, and Hatch knew the note of triumph in it. The jet from which the tip came was just on a level with his shoulder, set between a dressing table and a window. He leaned over and squinted at the gas pipe closely. Then he returned to the room where the valet was.

"Now, Jean," he began, in an even, calm voice, "please tell me _if you did or did not kill Miss Regnier purposely?_"

"I don't know what you mean," said the servant sullenly, angrily, as he turned on the scientist.

"You speak very good English now," was The Thinking Machine's terse comment. "Mr. Hatch, lock the door and use this 'phone to call the police."

Hatch turned to do as he was bid and saw a flash of steel in young Cabell's hand, which was drawn suddenly from a hip pocket. It was a revolver. The weapon glittered in the light, and Hatch flung himself forward. There was a sharp report, and a bullet was buried in the floor.

Then came a fierce, hard fight for possession of the revolver. It ended with the weapon in Hatch's hand, and both he and Cabell blowing from the effort they had expended. Jean, the valet, had turned at the sound of the shot and started toward the door leading into the hall. The Thinking Machine had stepped in front of him, and now stood there with his back to the door. Physically he would have been a child in the hands of the valet, yet there was a look in his eyes which stopped him.

"Now, Mr. Hatch," said the scientist quietly, a touch of irony in his voice, "hand me the revolver, then 'phone for Detective Mallory to come here immediately. Tell him we have a murderer--and if he can't come at once get some other detective whom you know."

"Murderer!" gasped Cabell.

Uncontrollable rage was blazing in the eyes of the valet, and he made as if to throw The Thinking Machine aside, despite the revolver, when Hatch was at the telephone. As Jean started forward, however, Cabell stopped him with a quick, stern gesture. Suddenly the young Southerner turned on The Thinking Machine; but it was with a question.

"What does it all mean?" he asked, bewildered.

"It means that that man there," and The Thinking Machine indicated the valet by a nod of his head, "is a murderer--that he killed Louise Regnier; that he shot Weldon Henley on Boston Common, and that, with the aid of Miss Regnier, he had four times previously attempted to kill Mr. Henley. Is he coming, Mr. Hatch?"

"Yes," was the reply. "He says he'll be here directly."

"Do you deny it?" demanded The Thinking Machine of the valet.

"I've done nothing," said the valet sullenly. "I'm going out of here."

Like an infuriated animal he rushed forward. Hatch and Cabell seized him and bore him to the floor. There, after a frantic struggle, he was bound and the other three men sat down to wait for Detective Mallory. Cabell sank back in his chair with a perplexed frown on his face. From time to time he glanced at Jean. The flush of anger which had been on the valet's face was gone now; instead there was the pallor of fear.

"Won't you tell us?" pleaded Cabell impatiently.

"When Detective Mallory comes and takes his prisoner," said The Thinking Machine.

Ten minutes later they heard a quick step in the hall outside and Hatch opened the door. Detective Mallory entered and looked from one to another inquiringly.

"That's your prisoner, Mr. Mallory," said the scientist, coldly. "I charge him with the murder of Miss Regnier, whom you were so confident committed suicide; I charge him with five attempts on the life of Weldon Henley, four times by gas poisoning, in which Miss Regnier was his accomplice, and once by shooting. He is the man who shot Mr. Henley."

The Thinking Machine arose and walked over to the prostrate man, handing the revolver to Hatch. He glared down at Jean fiercely.

"Will you tell how you did it or shall I?" he demanded.

His answer was a sullen, defiant glare. He turned and picked up the square mirror which the valet had produced previously.

"That's where the screw was, isn't it?" he asked, as he indicated a small hole in the frame of the mirror. Jean stared at it and his head sank forward hopelessly. "And this is the bath robe you wore, isn't it?" he demanded again, and from the suit case he pulled out the garment with the scarlet stripe.

"I guess you got me all right," was the sullen reply.

"It might be better for you if you told the story then?" suggested The Thinking Machine.

"You know so much about it, tell it yourself."

"Very well," was the calm rejoinder. "I will. If I make any mistake you will correct me."

For a long time no one spoke. The Thinking Machine had dropped back into a chair and was staring through his thick glasses at the ceiling; his finger tips were pressed tightly together. At last he began:

"There are certain trivial gaps which only the imagination can supply until the matter is gone into more fully. I should have supplied these myself, but the arrest of this man, Jean, was precipitated by the attempted hurried departure of Mr. Cabell for the South to-night, and I did not have time to go into the case to the fullest extent.

"Thus, we begin with the fact that there were several clever attempts made to murder Mr. Henley. This was by putting out the gas which he habitually left burning in his room. It happened four times in all; thus proving that it was an attempt to kill him. If it had been only once it might have been accident, even twice it might have been accident, but the same accident does not happen four times at the same time of night.

"Mr. Henley finally grew to regard the strange extinguishing of the gas as an effort to kill him, and carefully locked and barred his door and windows each night. He believed that some one came into his apartments and put out the light, leaving the gas flow. This, of course, was not true. Yet the gas was put out. How? My first idea, a natural one, was that it was turned off for an instant at the meter, when the light would go out, then turned on again. This, I convinced myself, was not true. Therefore still the question--how?

"It is a fact--I don't know how widely known it is--but it is a fact that every gas light in this house might be extinguished at the same time from this room without leaving it. How? Simply by removing the gas jet tip and blowing into the gas pipe. It would not leave a jet in the building burning. It is due to the fact that the lung power is greater than the pressure of the gas in the pipes, and forces it out.

"Thus we have the method employed to extinguish the light in Mr. Henley's rooms, and all the barred and locked doors and windows would not stop it. At the same time it threatened the life of every other person in the house--that is, every other person who used gas. It was probably for this reason that the attempt was always made late at night, I should say three or four o'clock. That's when it was done, isn't it?" he asked suddenly of the valet.

Staring at The Thinking Machine in open-mouthed astonishment the valet nodded his acquiescence before he was fully aware of it.

"Yes, that's right," The Thinking Machine resumed complacently. "This was easily found out--comparatively. The next question was how was a watch kept on Mr. Henley? It would have done no good to extinguish the gas before he was asleep, or, to have turned it on when he was not in his rooms. It might have led to a speedy discovery of just how the thing was done.

"There's a spring lock on the door of Mr. Henley's apartment. Therefore it would have been impossible for anyone to peep through the keyhole. There are no cracks through which one might see. How was this watch kept? How was the plotter to satisfy himself positively of the time when Mr. Henley was asleep? How was it the gas was put out at no time of the score or more nights Mr. Henley himself kept watch? Obviously he was watched through a window.

"No one could climb out on the window ledge and look into Mr. Henley's apartments. No one could see into that apartment from the street--that is, could see whether Mr. Henley was asleep or even in bed. They could see the light. Watch was kept with the aid offered by the flagpole, supplemented with a mirror--this mirror. A screw was driven into the frame--it has been removed now--it was swung on the flagpole rope and pulled out to the end of the pole, facing the building. To a man standing in the hall window of the third floor it offered precisely the angle necessary to reflect the interior of Mr. Henley's suite, possibly even showed him in bed through a narrow opening in the curtain. There is no shade on the windows of that suite; heavy curtains instead. Is that right?"

Again the prisoner was surprised into a mute acquiescence.

"I saw the possibility of these things, and I saw, too, that at three or four o'clock in the morning it would be perfectly possible for a person to move about the upper halls of this house without being seen. If he wore a heavy bath robe, with a hood, say, no one would recognize him even if he were seen, and besides the garb would not cause suspicion. This bath robe has a hood.

"Now, in working the mirror back and forth on the flagpole at night a tiny scarlet thread was pulled out of the robe and clung to the rope. I found this thread; later Mr. Hatch found an identical thread in these apartments. Both came from that bath robe. Plain logic shows that the person who blew down the gas pipes worked the mirror trick; the person who worked the mirror trick left the thread; the thread comes back to the bath robe--that bath robe there," he pointed dramatically. "Thus the person who desired Henley's death was in these apartments, or had easy access to them."

He paused a moment and there was a tense silence. A great light was coming to Hatch, slowly but surely. The brain that had followed all this was unlimited in possibilities.

"Even before we traced the origin of the crime to this room," went on the scientist, quietly now, "attention had been attracted here, particularly to you, Mr. Cabell. It was through the love affair, of which Miss Lipscomb was the center. Mr. Hatch learned that you and Henley had been rivals for her hand. It was that, even before this scarlet thread was found, which indicated that you might have some knowledge of the affair, directly or indirectly.

"You are not a malicious or revengeful man, Mr. Cabell. But you are hot-tempered--extremely so. You demonstrated that just now, when, angry and not understanding, but feeling that your honor was at stake, you shot a hole in the floor."

"What?" asked Detective Mallory.

"A little accident," explained The Thinking Machine quickly. "Not being a malicious or revengeful man, you are not the man to deliberately go ahead, and make elaborate plans for the murder of Henley. In a moment of passion you might have killed him--but never deliberately as the result of premeditation. Besides you were out of town. Who was then in these apartments? Who had access to these apartments? Who might have used your bath robe? Your valet, possibly Miss Austin. Which? Now, let's see how we reached this conclusion which led to the valet.

"Miss Regnier was found dead. It was not suicide. How did I know? Because she had been reading with the gas light at its full. If she had been reading by the gas light, how was it then that it went out and suffocated her before she could arise and shut it off? Obviously she must have fallen asleep over her book and left the light burning.

"If she was in this plot to kill Henley, why did she light the jet in her room? There might have been some slight defect in the electric bulb in her room which she had just discovered. Therefore she lighted the gas, intending to extinguish it--turn it off entirely--later. But she fell asleep. Therefore when the valet here blew into the pipe, intending to kill Mr. Henley, he unwittingly killed the woman he loved--Miss Regnier. It was perfectly possible, meanwhile, that she did not know of the attempt to be made that particular night, although she had participated in the others, knowing that Henley had night after night sat up to watch the light in his rooms.

"The facts, as I knew them, showed no connection between Miss Regnier and this man at that time--nor any connection between Miss Regnier and Henley. It might have been that the person who blew the gas out of the pipe from these rooms knew nothing whatever of Miss Regnier, just as he didn't know who else he might have killed in the building.

"But I had her death and the manner of it. I had eliminated you, Mr. Cabell. Therefore there remained Miss Austin and the valet. Miss Austin was eccentric--insane, if you will. Would she have any motive for killing Henley? I could imagine none. Love? Probably not. Money? They had nothing in common on that ground. What? Nothing that I could see. Therefore, for the moment, I passed Miss Austin by, after asking you, Mr. Cabell, if you were Miss Austin.

"What remained? The valet. Motive? Several possible ones, one or two probable. He is French, or says he is. Miss Regnier is French. Therefore I had arrived at the conclusion that they knew each other as people of the same nationality will in a house of this sort. And remember, I had passed by Mr. Cabell and Miss Austin, so the valet was the only one left; he could use the bath robe.

"Well, the motive. Frankly that was the only difficult point in the entire problem--difficult because there were so many possibilities. And each possibility that suggested itself suggested also a woman. Jealousy? There must be a woman. Hate? Probably a woman. Attempted extortion? With the aid of a woman. No other motive which would lead to so elaborate a plot of murder would come forward. Who was the woman? Miss Regnier.

"Did Miss Regnier know Henley? Mr. Hatch had reason to believe he knew her because of his actions when informed of her death. Knew her how? People of such relatively different planes of life can know each other--or do know each other--only on one plane. Henley is a typical young man, fast, I dare say, and liberal. Perhaps, then, there had been a liaison. When I saw this possibility I had my motives--all of them--jealousy, hate and possibly attempted extortion as well.

"What was more possible than Mr. Henley and Miss Regnier had been acquainted? All liaisons are secret ones. Suppose she had been cast off because of the engagement to a young woman of Henley's own level? Suppose she had confided in the valet here? Do you see? Motives enough for any crime, however diabolical. The attempts on Henley's life possibly followed an attempted extortion of money. The shot which wounded Henley was fired by this man, Jean. Why? Because the woman who had cause to hate Henley was dead. Then the man? He was alive and vindictive. Henley knew who shot him, and knew why, but he'll never say it publicly. He can't afford to. It would ruin him. I think probably that's all. Do you want to add anything?" he asked of the valet.

"No," was the fierce reply. "I'm sorry I didn't kill him, that's all. It was all about as you said, though God knows how you found it out," he added, desperately.

"Are you a Frenchman?"

"I was born in New York, but lived in France for eleven years. I first knew Louise there."

Silence fell upon the little group. Then Hatch asked a question:

"You told me, Professor, that there would be no other attempt to kill Henley by extinguishing the gas. How did you know that?"

"Because one person--the wrong person--had been killed that way," was the reply. "For this reason it was hardly likely that another attempt of that sort would be made. You had no intention of killing Louise Regnier, had you, Jean?"

"No, God help me, no."

"It was all done in these apartments," The Thinking Machine added, turning to Cabell, "at the gas jet from which I took the tip. It had been only loosely replaced and the metal was tarnished where the lips had dampened it."

"It must take great lung power to do a thing like that," remarked Detective Mallory.

"You would be amazed to know how easily it is done," said the scientist. "Try it some time."

The Thinking Machine arose and picked up his hat; Hatch did the same. Then the reporter turned to Cabell.

"Would you mind telling me why you were so anxious to get away to-night?" he asked.

"Well, no," Cabell explained, and there was a rush of red to his face. "It's because I received a telegram from Virginia--Miss Lipscomb, in fact. Some of Henley's past had come to her knowledge and the telegram told me that the engagement was broken. On top of this came the information that Henley had been shot and--I was considerably agitated."

The Thinking Machine and Hatch were walking along the street.

"What did you write in the note you sent to Cabell that made him start to unpack?" asked the reporter, curiously.

"There are some things that it wouldn't be well for everyone to know," was the enigmatic response. "Perhaps it would be just as well for you to overlook this little omission."

"Of course, of course," replied the reporter, wonderingly.

Here are the facts in the case as they were known in the beginning to Professor Augustus S. F. X. Van Dusen, scientist and logician. After hearing a statement of the problem from the lips of its principal he declared it to be one of the most engaging that had ever come to his attention, and----

But let me begin at the beginning:

* * * * *

The Thinking Machine was in the small laboratory of his modest apartments at two o'clock in the afternoon. Martha, the scientist's only servant, appeared at the door with a puzzled expression on her wrinkled face.

"A gentleman to see you, sir," she said.

"Name?" inquired The Thinking Machine, without turning.

"He--he didn't give it, sir," she stammered.

"I have told you always, Martha, to ask names of callers."

"I did ask his name, sir, and--and he said he didn't know it."

The Thinking Machine was never surprised, yet now he turned on Martha in perplexity and squinted at her fiercely through his thick glasses.

"Don't know his own name?" he repeated. "Dear me! How careless! Show the gentleman into the reception room immediately."

With no more introduction to the problem than this, therefore, The Thinking Machine passed into the other room. A stranger arose and came forward. He was tall, of apparently thirty-five years, clean-shaven and had the keen, alert face of a man of affairs. He would have been handsome had it not been for dark rings under the eyes and the unusual white of his face. He was immaculately dressed from top to toe; altogether a man who would attract attention.

For a moment he regarded the scientist curiously; perhaps there was a trace of well-bred astonishment in his manner. He gazed curiously at the enormous head, with its shock of yellow hair, and noted, too, the droop in the thin shoulders. Thus for a moment they stood, face to face, the tall stranger making The Thinking Machine dwarf-like by comparison.

"Well?" asked the scientist.

The stranger turned as if to pace back and forth across the room, then instead dropped into a chair which the scientist indicated.

"I have heard a great deal about you, Professor," he began, in a well-modulated voice, "and at last it occurred to me to come to you for advice. I am in a most remarkable position--and I'm not insane. Don't think that, please. But unless I see some way out of this amazing predicament I shall be. As it is now, my nerves have gone; I am not myself."

"Your story? What is it? How can I help you?"

"I am lost, hopelessly lost," the stranger resumed. "I know neither my home, my business, nor even my name. I know nothing whatever of myself or my life; what it was or what it might have been previous to four weeks ago. I am seeking light on my identity. Now, if there is any fee----"

"Never mind that," the scientist put in, and he squinted steadily into the eyes of the visitor. "What _do_ you know? From the time you remember things tell me all of it."

He sank back into his chair, squinting steadily upward. The stranger arose, paced back and forth across the room several times and then dropped into his chair again.

"It's perfectly incomprehensible," he said. "It's precisely as if I, full grown, had been born into a world of which I knew nothing except its language. The ordinary things, chairs, tables and such things, are perfectly familiar, but who I am, where I came from, why I came--of these I have no idea. I will tell you just as my impressions came to me when I awoke one morning, four weeks ago.

"It was eight or nine o'clock, I suppose. I was in a room. I knew instantly it was a hotel, but had not the faintest idea of how I got there, or of ever having seen the room before. I didn't even know my own clothing when I started to dress. I glanced out of my window; the scene was wholly strange to me.

"For half an hour or so I remained in my room, dressing and wondering what it meant. Then, suddenly, in the midst of my other worries, it came home to me that I didn't know my own name, the place where I lived nor anything about myself. I didn't know what hotel I was in. In terror I looked into a mirror. The face reflected at me was not one I knew. It didn't seem to be the face of a stranger; it was merely not a face that I knew.

"The thing was unbelievable. Then I began a search of my clothing for some trace of my identity. I found nothing whatever that would enlighten me--not a scrap of paper of any kind, no personal or business card."

"Have a watch?" asked The Thinking Machine.

"Any money?"

"Yes, money," said the stranger. "There was a bundle of more than ten thousand dollars in my pocket, in one-hundred-dollar bills. Whose it is or where it came from I don't know. I have been living on it since, and shall continue to do so, but I don't know if it is mine. I knew it was money when I saw it, but did not recollect ever having seen any previously."

"Any jewelry?"

"These cuff buttons," and the stranger exhibited a pair which he drew from his pocket.

"Go on."

"I finally finished dressing and went down to the office. It was my purpose to find out the name of the hotel and who I was. I knew I could learn some of this from the hotel register without attracting any attention or making anyone think I was insane. I had noted the number of my room. It was twenty-seven.

"I looked over the hotel register casually. I saw I was at the Hotel Yarmouth in Boston. I looked carefully down the pages until I came to the number of my room. Opposite this number was a name--John Doane, but where the name of the city should have been there was only a dash."

"You realize that it is perfectly possible that John Doane is your name?" asked The Thinking Machine.

"Certainly," was the reply. "But I have no recollection of ever having heard it before. This register showed that I had arrived at the hotel the night before--or rather that John Doane had arrived and been assigned to Room 27, and I was the John Doane, presumably. From that moment to this the hotel people have known me as John Doane, as have other people whom I have met during the four weeks since I awoke."

"Did the handwriting recall nothing?"

"Nothing whatever."

"Is it anything like the handwriting you write now?"

"Identical, so far as I can see."

"Did you have any baggage or checks for baggage?"

"No. All I had was the money and this clothing I stand in. Of course, since then I have bought necessities."

Both were silent for a long time and finally the stranger--Doane--arose and began pacing nervously again.

"That a tailor-made suit?" asked the scientist.

"Yes," said Doane, quickly. "I know what you mean. Tailor-made garments have linen strips sewed inside the pockets on which are the names of the manufacturers and the name of the man for whom the clothes were made, together with the date. I looked for those. They had been removed, cut out."

"Ah!" exclaimed The Thinking Machine suddenly. "No laundry marks on your linen either, I suppose?"

"No. It was all perfectly new."

"Name of the maker on it?"

"No. That had been cut out, too."

Doane was pacing back and forth across the reception room; the scientist lay back in his chair.

"Do you know the circumstances of your arrival at the hotel?" he asked at last.

"Yes. I asked, guardedly enough, you may be sure, hinting to the clerk that I had been drunk so as not to make him think I was insane. He said I came in about eleven o'clock at night, without any baggage, paid for my room with a one-hundred-dollar bill, which he changed, registered and went upstairs. I said nothing that he recalls beyond making a request for a room."

"The name Doane is not familiar to you?"

"No."

"You can't recall a wife or children?"

"Do you speak any foreign language?"

"Is your mind clear now? Do you remember things?"

"I remember perfectly every incident since I awoke in the hotel," said Doane. "I seem to remember with remarkable clearness, and somehow I attach the gravest importance to the most trivial incidents."

The Thinking Machine arose and motioned to Doane to sit down. He dropped back into a seat wearily. Then the scientist's long, slender fingers ran lightly, deftly through the abundant black hair of his visitor. Finally they passed down from the hair and along the firm jaws; thence they went to the arms, where they pressed upon good, substantial muscles. At last the hands, well shaped and white, were examined minutely. A magnifying glass was used to facilitate this examination. Finally The Thinking Machine stared into the quick-moving, nervous eyes of the stranger.

"Any marks at all on your body?" he asked at last.

"No," Doane responded. "I had thought of that and sought for an hour for some sort of mark. There's nothing--nothing." The eyes glittered a little and finally, in a burst of nervousness, he struggled to his feet. "My God!" he exclaimed. "Is there nothing you can do? What is it all, anyway?"

"Seems to be a remarkable form of aphasia," replied The Thinking Machine. "That's not an uncommon disease among people whose minds and nerves are overwrought. You've simply lost yourself--lost your identity. If it is aphasia, you will recover in time. When, I don't know."

"And meantime?"

"Let me see the money you found."

With trembling hands Doane produced a large roll of bills, principally hundreds, many of them perfectly new. The Thinking Machine examined them minutely, and finally made some memoranda on a slip of paper. The money was then returned to Doane.

"Now, what shall I do?" asked the latter.

"Don't worry," advised the scientist. "I'll do what I can."

"And--tell me who and what I am?"

"Oh, I can find that out all right," remarked The Thinking Machine. "But there's a possibility that you wouldn't recall even if I told you all about yourself."

When John Doane of Nowhere--to all practical purposes--left the home of The Thinking Machine he bore instructions of divers kinds. First he was to get a large map of the United States and study it closely, reading over and pronouncing aloud the name of every city, town and village he found. After an hour of this he was to take a city directory and read over the names, pronouncing them aloud as he did so. Then he was to make out a list of the various professions and higher commercial pursuits, and pronounce these. All these things were calculated, obviously, to arouse the sleeping brain. After Doane had gone The Thinking Machine called up Hutchinson Hatch, reporter, on the 'phone.

"Come up immediately," he requested. "There's something that will interest you."

"A mystery?" Hatch inquired, eagerly.

"One of the most engaging problems that has ever come to my attention," replied the scientist.

It was only a question of a few minutes before Hatch was ushered in. He was a living interrogation point, and repressed a rush of questions with a distinct effort. The Thinking Machine finally told what he knew.

"Now it seems to be," said The Thinking Machine, and he emphasized the "seems," The man simply doesn't know himself. I examined him closely. I went over his head for a sign of a possible depression, or abnormality. It didn't appear. I examined his muscles. He has biceps of great power, is evidently now or has been athletic. His hands are white, well cared for and have no marks on them. They are not the hands of a man who has ever done physical work. The money in his pocket tends to confirm the fact that he is not of that sphere.

"Then what is he? Lawyer? Banker? Financier? What? He might be either, yet he impressed me as being rather of the business than the professional school. He has a good, square-cut jaw--the jaw of a fighting man--and his poise gives one the impression that whatever he has been doing he has been foremost in it. Being foremost in it, he would naturally drift to a city, a big city. He is typically a city man.

"Now, please, to aid me, communicate with your correspondents in the large cities and find if such a name as John Doane appears in any directory. Is he at home now? Has he a family? All about him."

"Do you believe that John Doane is his name?" asked the reporter.

"No reason why it shouldn't be," said The Thinking Machine. "Yet it might not be."

"How about inquiries in this city?"

"He can't well be a local man," was the reply. "He has been wandering about the streets for four weeks, and if he had lived here he would have met some one who knew him."

"But the money?"

"I'll probably be able to locate him through that," said The Thinking Machine. "The matter is not at all clear to me now, but it occurs to me that he is a man of consequence, and that it was possibly necessary for some one to get rid of him for a time."

"Well, if it's plain aphasia, as you say," the reporter put in, "it seems rather difficult to imagine that the attack came at a moment when it was necessary to get rid of him."

"I say it _seems_ like aphasia," said the scientist, crustily. "There are known drugs which will produce the identical effect if properly administered."

"Oh," said Hatch. He was beginning to see.

"There is one drug particularly, made in India, and not unlike hasheesh. In a case of this kind anything is possible. To-morrow I shall ask you to take Mr. Doane down through the financial district, as an experiment. When you go there I want you particularly to get him to the sound of the 'ticker.' It will be an interesting experiment."

The reporter went away and The Thinking Machine sent a telegram to the Blank National Bank of Butte, Montana:

"To whom did you issue hundred-dollar bills, series B, numbering 846380 to 846395 inclusive? Please answer."

It was ten o'clock next day when Hatch called on The Thinking Machine. There he was introduced to John Doane, the man who was lost. The Thinking Machine was asking questions of Mr. Doane when Hatch was ushered in.

"Did the map recall nothing?"

"Nothing."

"Montana, Montana, Montana," the scientist repeated monotonously; "think of it. Butte, Montana."

Doane shook his head hopelessly, sadly.

"Cowboy, cowboy. Did you ever see a cowboy?" Again the head shake.

"Coyote--something like a wolf--coyote. Don't you recall ever having seen one?"

"I'm afraid it's hopeless," remarked the other.

There was a note of more than ordinary irritation in The Thinking Machine's voice when he turned to Hatch.

"Mr. Hatch, will you walk through the financial district with Mr. Doane?" he asked. "Please go to the places I suggested."

So it came to pass that the reporter and Doane went out together, walking through the crowded, hurrying, bustling financial district. The first place visited was a private room where market quotations were displayed on a blackboard. Mr. Doane was interested, but the scene seemed to suggest nothing.

He looked upon it all as any stranger might have done. After a time they passed out. Suddenly a man came running toward them--evidently a broker.

"What's the matter?" asked another.

"Montana copper's gone to smash," was the reply.

"_Copper!_ _Copper!_" gasped Doane suddenly.

Hatch looked around quickly at his companion. Doane's face was a study. On it was half realization and a deep perplexed wrinkle, a glimmer even of excitement.

"Copper!!" he repeated.

"Does the word mean anything to you?" asked Hatch quickly. "Copper--metal, you know."

"Copper, copper, copper," the other repeated. Then, as Hatch looked, the queer expression faded; there came again utter hopelessness.

There are many men with powerful names who operate in the Street--some of them in copper. Hatch led Doane straight to the office of one of these men and there introduced him to a partner in the business.

"We want to talk about copper a little," Hatch explained, still eying his companion.

"Do you want to buy or sell?" asked the broker.

"Sell," said Doane suddenly. "Sell, sell, sell copper. That's it--copper."

He turned to Hatch, stared at him dully a moment, a deathly pallor came over his face, then, with upraised hands, fell senseless.

Still unconscious, the man of mystery was removed to the home of The Thinking Machine and there stretched out on a sofa. The Thinking Machine was bending over him, this time in his capacity of physician, making an examination. Hatch stood by, looking on curiously.

"I never saw anything like it," Hatch remarked. "He just threw up his hands and collapsed. He hasn't been conscious since."

"It may be that when he comes to he will have recovered his memory, and in that event he will have absolutely no recollection whatever of you and me," explained The Thinking Machine.

Doane moved a little at last, and under a stimulant the color began to creep back into his pallid face.

"Just what was said, Mr. Hatch, before he collapsed?" asked the scientist.

Hatch explained, repeating the conversation as he remembered it.

"And he said 'sell,'" mused The Thinking Machine. "In other words, he thinks--or imagines he knows--that copper is to drop. I believe the first remark he heard was that copper had gone to smash--down, I presume that means?"

"Yes," the reporter replied.

Half an hour later John Doane sat up on the couch and looked about the room.

"Ah, Professor," he remarked. "I fainted, didn't I?"

The Thinking Machine was disappointed because his patient had not recovered memory with consciousness. The remark showed that he was still in the same mental condition--the man who was lost.

"Sell copper, sell, sell, sell," repeated The Thinking Machine, commandingly.

"Yes, yes, sell," was the reply.

The reflection of some great mental struggle was on Doane's face; he was seeking to recall something which persistently eluded him.

"Copper, copper," the scientist repeated, and he exhibited a penny.

"Yes, copper," said Doane. "I know. A penny."

"Why did you say sell copper?"

"I don't know," was the weary reply. "It seemed to be an unconscious act entirely. I don't know."

He clasped and unclasped his hands nervously and sat for a long time dully staring at the floor. The fight for memory was a dramatic one.

"It seemed to me," Doane explained after awhile, "that the word copper touched some responsive chord in my memory, then it was lost again. Some time in the past, I think, I must have had something to do with copper."

"Yes," said The Thinking Machine, and he rubbed his slender fingers briskly. "Now you are coming around again."

His remarks were interrupted by the appearance of Martha at the door with a telegram. The Thinking Machine opened it hastily. What he saw perplexed him again.

"Dear me! Most extraordinary!" he exclaimed. "What is it?" asked Hatch, curiously.

The scientist turned to Doane again.

"Do you happen to remember Preston Bell?" he demanded, emphasizing the name explosively.

"Preston Bell?" the other repeated, and again the mental struggle was apparent on his face. "Preston Bell!"

"Cashier of the Blank National Bank of Butte, Montana?" urged the other, still in an emphatic tone. "Cashier Bell?"

He leaned forward eagerly and watched the face of his patient; Hatch unconsciously did the same. Once there was almost realization, and seeing it The Thinking Machine sought to bring back full memory.

"Bell, cashier, copper," he repeated, time after time.

The flash of realization which had been on Doane's face passed, and there came infinite weariness--the weariness of one who is ill.

"I don't remember," he said at last. "I'm very tired."

"Stretch out there on the couch and go to sleep," advised The Thinking Machine, and he arose to arrange a pillow. "Sleep will do you more good than anything else right now. But before you lie down, let me have, please, a few of those hundred-dollar bills you found."

Doane extended the roll of money, and then slept like a child. It was uncanny to Hatch, who had been a deeply interested spectator.

The Thinking Machine ran over the bills and finally selected fifteen of them--bills that were new and crisp. They were of an issue by the Blank National Bank of Butte, Montana. The Thinking Machine stared at the money closely, then handed it to Hatch.

"Does that look like counterfeit to you?" he asked.

"Counterfeit?" gasped Hatch. "Counterfeit?" he repeated. He took the bills and examined them. "So far as I can see they seem to be good," he went on, "though I have never had enough experience with one-hundred-dollar bills to qualify as an expert."

"Do you know an expert?"

"Yes."

"See him immediately. Take fifteen bills and ask him to pass on them, each and every one. Tell him you have reason--excellent reason--to believe that they are counterfeit. When he gives his opinion come back to me."

Hatch went away with the money in his pocket. Then The Thinking Machine wrote another telegram, addressed to President Bell, cashier of the Butte Bank. It was as follows:

"Please send me full details of the manner in which money previously described was lost, with names of all persons who might have had any knowledge of the matter. Highly important to your bank and to justice. Will communicate in detail on receipt of your answer."

Then, while his visitor slept, The Thinking Machine quietly removed his shoes and examined them. He found, almost worn away, the name of the maker. This was subjected to close scrutiny under the magnifying glass, after which The Thinking Machine arose with a perceptible expression of relief on his face.

"Why didn't I think of that before?" he demanded of himself.

Then other telegrams went into the West. One was to a customs shoemaker in Denver, Colorado:

"To what financier or banker have you sold within three months a pair of shoes, Senate brand, calfskin blucher, number eight, D last? Do you know John Doane?"

A second telegram went to the Chief of Police of Denver. It was:

"Please wire if any financier, banker or business man has been out of your city for five weeks or more, presumably on business trip. Do you know John Doane?"

Then The Thinking Machine sat down to wait. At last the door bell rang and Hatch entered.

"Well?" demanded the scientist, impatiently.

"The expert declares those are not counterfeit," said Hatch.

Now The Thinking Machine was surprised. It was shown clearly by the quick lifting of the eyebrows, by the sudden snap of his jaws, by a quick forward movement of the yellow head.

"Well, well, well!" he exclaimed at last. Then again: "Well, well!"

"What is it?"

"See here," and The Thinking Machine took the hundred-dollar bills in his own hands. "These bills, perfectly new and crisp, were issued by the Blank National Bank of Butte, and the fact that they are in proper sequence would indicate that they were issued to one individual at the same time, probably recently. There can be no doubt of that. The numbers run from 846380 to 846395, all series B.

"I see," said Hatch.

"Now read that," and the scientist extended to the reporter the telegram Martha had brought in just before Hatch had gone away. Hatch read this:

"Series B, hundred-dollar bills 846380 to 846395 issued by this bank are not in existence. Were destroyed by fire, together with twenty-seven others of the same series. Government has been asked to grant permission to reissue these numbers.

"Preston Bell, Cashier."

The reporter looked up with a question in his eyes.

"It means," said The Thinking Machine, "that this man is either a thief or the victim of some sort of financial jugglery."

"In that case is he what he pretends to be--a man who doesn't know himself?" asked the reporter.

"That remains to be seen."

Event followed event with startling rapidity during the next few hours. First came a message from the Chief of Police of Denver. No capitalist or financier of consequence was out of Denver at the moment, so far as his men could ascertain. Longer search might be fruitful. He did not know John Doane. One John Doane in the directory was a teamster.

Then from the Blank National Bank came another telegram signed "Preston Bell, Cashier," reciting the circumstances of the disappearance of the hundred-dollar bills. The Blank National Bank had moved into a new structure; within a week there had been a fire which destroyed it. Several packages of money, including one package of hundred-dollar bills, among them those specified by The Thinking Machine, had been burned. President Harrison of the bank immediately made affidavit to the Government that these bills were left in his office.

The Thinking Machine studied this telegram carefully and from time to time glanced at it while Hatch made his report. This was as to the work of the correspondents who had been seeking John Doane. They found many men of the name and reported at length on each. One by one The Thinking Machine heard the reports, then shook his head.

Finally he reverted again to the telegram, and after consideration sent another--this time to the Chief of Police of Butte. In it he asked these questions:

"Has there ever been any financial trouble in Blank National Bank? Was there an embezzlement or shortage at any time? What is reputation of President Harrison? What is reputation of Cashier Bell? Do you know John Doane?"

In due course of events the answer came. It was brief and to the point. It said:

"Harrison recently embezzled $175,000 and disappeared. Bell's reputation excellent; now out of city. Don't know John Doane. If you have any trace of Harrison, wire quick."

This answer came just after Doane awoke, apparently greatly refreshed, but himself again--that is, himself in so far as he was still lost. For an hour The Thinking Machine pounded him with questions--questions of all sorts, serious, religious and at times seemingly silly. They apparently aroused no trace of memory, save when the name Preston Bell was mentioned; then there was the strange, puzzled expression on Doane's face.

"Harrison--do you know him?" asked the scientist. "President of the Blank National Bank of Butte?"

There was only an uncomprehending stare for an answer. After a long time of this The Thinking Machine instructed Hatch and Doane to go for a walk. He had still a faint hope that some one might recognize Doane and speak to him. As they wandered aimlessly on two persons spoke to him. One was a man who nodded and passed on.

"Who was that?" asked Hatch quickly. "Do you remember ever having seen him before?"

"Oh, yes," was the reply. "He stops at my hotel. He knows me as Doane."

It was just a few minutes before six o'clock when, walking slowly, they passed a great office building. Coming toward them was a well-dressed, active man of thirty-five years or so. As he approached he removed a cigar from his lips.

"Hello, Harry!" he exclaimed, and reached for Doane's hand.

"Hello," said Doane, but there was no trace of recognition in his voice.

"How's Pittsburg?" asked the stranger.

"Oh, all right, I guess," said Doane, and there came new wrinkles of perplexity in his brow. "Allow me, Mr.--Mr.--really I have forgotten your name----"

"Manning," laughed the other.

"Mr. Hatch, Mr. Manning."

The reporter shook hands with Manning eagerly; he saw now a new line of possibilities suddenly revealed. Here was a man who knew Doane as Harry--and then Pittsburg, too.

"Last time I saw you was in Pittsburg, wasn't it?" Manning rattled on, as he led the way into a nearby cafe. "By George, that was a stiff game that night! Remember that jack full I held? It cost me nineteen hundred dollars," he added, ruefully.

"Yes, I remember," said Doane, but Hatch knew that he did not. And meanwhile a thousand questions were surging through the reporter's brain.

"Poker hands as expensive as that are liable to be long remembered," remarked Hatch, casually. "How long ago was that?"

"Three years, wasn't it, Harry?" asked Manning.

"All of that, I should say," was the reply.

"Twenty hours at the table," said Manning, and again he laughed cheerfully. "I was woozy when we finished."

Inside the café they sought out a table in a corner. No one else was near. When the waiter had gone, Hatch leaned over and looked Doane straight in the eyes.

"Shall I ask some questions?" he inquired.

"Yes, yes," said the other eagerly.

"What--what is it?" asked Manning.

"It's a remarkably strange chain of circumstances," said Hatch, in explanation. "This man whom you call Harry, we know as John Doane. What is his real name? Harry what?"

Manning stared at the reporter for a moment in amazement, then gradually a smile came to his lips.

"What are you trying to do?" he asked. "Is this a joke?"

"No, my God, man, can't you see?" exclaimed Doane, fiercely. "I'm ill, sick, something. I've lost my memory, all of my past. I don't remember anything about myself. What is my name?"

"Well, by George!" exclaimed Manning. "By George I don't believe I know your full name. Harry--Harry--what?"

He drew from his pocket several letters and half a dozen scraps of paper and ran over them. Then he looked carefully through a worn notebook.

"I don't know," he confessed. "I had your name and address in an old notebook, but I suppose I burned it. I remember, though, I met you in the Lincoln Club in Pittsburg three years ago. I called you Harry because everyone was calling everyone else by his first name. Your last name made no impression on me at all. By George!" he concluded, in a new burst of amazement.

"What were the circumstances, exactly?" asked Hatch.

"I'm a traveling man," Manning explained. "I go everywhere. A friend gave me a card to the Lincoln Club in Pittsburg and I went there. There were five or six of us playing poker, among them Mr.--Mr. Doane here. I sat at the same table with him for twenty hours or so, but I can't recall his last name to save me. It isn't Doane, I'm positive. I have an excellent memory for faces, and I know you're the man. Don't you remember me?"

"I haven't the slightest recollection of ever having seen you before in my life," was Doane's slow reply. "I have no recollection of ever having been in Pittsburg--no recollection of anything."

"Do you know if Mr. Doane is a resident of Pittsburg?" Hatch inquired. "Or was he there as a visitor, as you were?"

"Couldn't tell you to save my life," replied Manning. "Lord, it's amazing, isn't it? You don't remember me? You called me Bill all evening."

The other man shook his head.

"Well, say, is there anything I can do for you?"

"Nothing, thanks," said Doane. "Only tell me my name, and who I am."

"Lord, I don't know."

"What sort of a club is the Lincoln?" asked Hatch.

"It's a sort of a millionaire's club," Manning explained. "Lots of iron men belong to it. I had considerable business with them--that's what took me to Pittsburg."

"And you are absolutely positive this is the man you met there?"

"Why, I _know_ it. I never forget faces; it's my business to remember them."

"Did he say anything about a family?"

"Not that I recall. A man doesn't usually speak of his family at a poker table."

"Do you remember the exact date or the month?"

"I think it was in January or February possibly," was the reply. "It was bitterly cold and the snow was all smoked up. Yes, I'm positive it was in January, three years ago."

After awhile the men separated. Manning was stopping at the Hotel Teutonic and willingly gave his name and permanent address to Hatch, explaining at the same time that he would be in the city for several days and was perfectly willing to help in any way he could. He took also the address of The Thinking Machine.

From the café Hatch and Doane returned to the scientist. They found him with two telegrams spread out on a table before him. Briefly Hatch told the story of the meeting with Manning, while Doane sank down with his head in his hands. The Thinking Machine listened without comment.

"Here," he said, at the conclusion of the recital, and he offered one of the telegrams to Hatch. "I got the name of a shoemaker from Mr. Doane's shoe and wired to him in Denver, asking if he had a record of the sale. This is the answer. Read it aloud."

Hatch did so.

"Shoes such as described made nine weeks ago for Preston Bell, cashier Blank National Bank of Butte. Don't know John Doane."

"Well--what----" Doane began, bewildered.

"_It means that you are Preston Bell_," said Hatch, emphatically.

"No," said The Thinking Machine, quickly. "It means that there is only a strong probability of it."

* * * * *

The door bell rang. After a moment Martha appeared.

"A lady to see you, sir," she said.

"Her name?"

"Mrs. John Doane."

"Gentlemen, kindly step into the next room," requested The Thinking Machine.

Together Hatch and Doane passed through the door. There was an expression of--of--no man may say what--on Doane's face as he went.

"Show her in here, Martha," instructed the scientist.

There was a rustle of silk in the hall, the curtains on the door were pulled apart quickly and a richly gowned woman rushed into the room.

"My husband? Is he here?" she demanded, breathlessly. "I went to the hotel; they said he came here for treatment. Please, please, is he here?"

"A moment, madam," said The Thinking Machine. He stepped to the door through which Hatch and Doane had gone, and said something. One of them appeared in the door. It was Hutchinson Hatch.

"John, John, my darling husband," and the woman flung her arms about Hatch's neck. "Don't you know me?"

With blushing face Hatch looked over her shoulder into the eyes of The Thinking Machine, who stood briskly rubbing his hands. Never before in his long acquaintance with the scientist had Hatch seen him smile.

For a time there was silence, broken only by sobs, as the woman clung frantically to Hatch, with her face buried on his shoulder. Then:

"Don't you remember me?" she asked again and again. "Your wife? Don't you remember me?"

Hatch could still see the trace of a smile on the scientist's face, and said nothing.

"You are positive this gentleman is your husband?" inquired The Thinking Machine, finally.

"Oh, I know," the woman sobbed. "Oh, John, don't you remember me?" She drew away a little and looked deeply into the reporter's eyes. "Don't you remember me, John?"

"Can't say that I ever saw you before," said Hatch, truthfully enough. "I--I--fact is----"

"Mr. Doane's memory is wholly gone now," explained The Thinking Machine. "Meanwhile, perhaps you would tell me something about him. He is my patient. I am particularly interested."

The voice was soothing; it had lost for the moment its perpetual irritation. The woman sat down beside Hatch. Her face, pretty enough in a bold sort of way, was turned to The Thinking Machine inquiringly. With one hand she stroked that of the reporter.

"Where are you from?" began the scientist. "I mean where is the home of John Doane?"

"In Buffalo," she replied, glibly. "Didn't he even remember that?"

"And what's his business?"

"His health has been bad for some time and recently he gave up active business," said the woman. "Previously he was connected with a bank."

"When did you see him last?"

"Six weeks ago. He left the house one day and I have never heard from him since. I had Pinkerton men searching and at last they reported he was at the Yarmouth Hotel. I came on immediately. And now we shall go back to Buffalo." She turned to Hatch with a languishing glance. "Shall we not, dear?"

"Whatever Professor Van Dusen thinks best," was the equivocal reply.

Slowly the glimmer of amusement was passing out of the squint eyes of The Thinking Machine; as Hatch looked he saw a hardening of the lines of the mouth. There was an explosion coming. He knew it. Yet when the scientist spoke his voice was more velvety than ever.

"Mrs. Doane, do you happen to be acquainted with a drug which produces temporary loss of memory?"

She stared at him, but did not lose her self-possession.

"No," she said finally. "Why?"

"You know, of course, that this man is _not_ your husband?"

This time the question had its effect. The woman arose suddenly, stared at the two men, and her face went white.

"Not?--not?--what do you mean?"

"I mean," and the voice reassumed its tone of irritation, "I mean that I shall send for the police and give you in their charge unless you tell me the truth about this affair. Is that perfectly clear to you?"

The woman's lips were pressed tightly together. She saw that she had fallen into some sort of a trap; her gloved hands were clenched fiercely; the pallor faded and a flush of anger came.

"Further, for fear you don't quite follow me even now," explained The Thinking Machine, "I will say that I know all about this copper deal of which this so-called John Doane was the victim. _I know his condition now_. If you tell the truth you may escape prison--if you don't, there is a long term, not only for you, but for your fellow-conspirators. Now will you talk?"

"No," said the woman. She arose as if to go out.

"Never mind that," said The Thinking Machine. "You had better stay where you are. You will be locked up at the proper moment. Mr. Hatch, please 'phone for Detective Mallory."

Hatch arose and passed into the adjoining room. "You tricked me," the woman screamed suddenly, fiercely.

"Yes," the other agreed, complacently. "Next time be sure you know your own husband. Meanwhile where is Harrison?"

"Not another word," was the quick reply.

"Very well," said the scientist, calmly. "Detective Mallory will be here in a few minutes. Meanwhile I'll lock this door."

"You have no right----" the woman began.

Without heeding the remark, The Thinking Machine passed into the adjoining room. There for half an hour he talked earnestly to Hatch and Doane. At the end of that time he sent a telegram to the manager of the Lincoln Club in Pittsburg, as follows:

"Does your visitors' book show any man, registered there in the month of January three years ago, whose first name is Harry or Henry? If so, please wire name and description, also name of man whose guest he was."

This telegram was dispatched. A few minutes later the door bell rang and Detective Mallory entered.

"What is it?" he inquired.

"A prisoner for you in the next room," was the reply. "A woman. I charge her with conspiracy to defraud a man who for the present we will call John Doane. That may or may not be his name."

"What do you know about it?" asked the detective.

"A great deal now--more after awhile. I shall tell you then. Meanwhile take this woman. You gentlemen, I should suggest, might go out somewhere this evening. If you drop by afterwards there may be an answer to a few telegrams which will make this matter clear."

Protestingly the mysterious woman was led away by Detective Mallory; and Doane and Hatch followed shortly after. The next act of The Thinking Machine was to write a telegram addressed to Mrs. Preston Bell, Butte, Montana. Here it is:

"Your husband suffering temporary mental trouble here. Can you come on immediately? Answer."

When the messenger boy came for the telegram he found a man on the stoop. The Thinking Machine received the telegram, and the man, who gave to Martha the name of Manning, was announced.

"Manning, too," mused the scientist. "Show him in."

"I don't know if you know why I am here," explained Manning.

"Oh, yes," said the scientist. "You have remembered Doane's name. What is it, please?"

Manning was too frankly surprised to answer and only stared at the scientist.

"Yes, that's right," he said finally, and he smiled. "His name is Pillsbury. I recall it now."

"And what made you recall it?"

"I noticed an advertisement in a magazine with the name in large letters. It instantly came to me that that was Doane's real name."

"Thanks," remarked the scientist. "And the woman--who is she?"

"What woman?" asked Manning.

"Never mind, then. I am deeply obliged for your information. I don't suppose you know anything else about it?"

"No," said Manning. He was a little bewildered, and after awhile went away.

For an hour or more The Thinking Machine sat with finger tips pressed together staring at the ceiling. His meditations were interrupted by Martha.

"Another telegram, sir."

The Thinking Machine took it eagerly. It was from the manager of the Lincoln Club in Pittsburg:

"Henry C. Carney, Harry Meltz, Henry Blake, Henry W. Tolman, Harry Pillsbury, Henry Calvert and Henry Louis Smith all visitors to dub in month you name. Which do you want to learn more about?"

It took more than an hour for The Thinking Machine to establish long distance connection by 'phone with Pittsburg. When he had finished talking he seemed satisfied.

"Now," he mused. "The answer from Mrs. Preston."

It was nearly midnight when that came. Hatch and Doane had returned from a theater and were talking to the scientist when the telegram, was brought in.

"Anything important?" asked Doane, anxiously.

"Yes," said the scientist, and he slipped a finger beneath the flap of the envelope. "It's clear now. It was an engaging problem from first to last, and now----"

He opened the telegram and glanced at it; then with bewilderment on his face and mouth slightly open he sank down at the table and leaned forward with his head on his arms. The message fluttered to the table and Hatch read this:

"Man in Boston can't be my husband. He is now in Honolulu. I received cablegram from him to-day.

"Mrs. Preston Bell."

It was thirty-six hours later that the three men met again. The Thinking Machine had abruptly dismissed Hatch and Doane the last time. The reporter knew that something wholly unexpected had happened. He could only conjecture that this had to do with Preston Bell. When the three met again it was in Detective Mallory's office at police headquarters. The mysterious woman who had claimed Doane for her husband was present, as were Mallory, Hatch, Doane and The Thinking Machine.

"Has this woman given any name?" was the scientist's first question.

"Mary Jones," replied the detective, with a grin.

"And address?"

"No."

"Is her picture in the Rogues' Gallery?"

"No. I looked carefully."

"Anybody called to ask about her?"

"A man--yes. That is, he didn't ask about her--he merely asked some general questions, which now we believe were to find out about her."

The Thinking Machine arose and walked over to the woman. She looked up at him defiantly.

"There has been a mistake made, Mr. Mallory," said the scientist. "It's my fault entirely. Let this woman go. I am sorry to have done her so grave an injustice."

Instantly the woman was on her feet, her face radiant. A look of disgust crept into Mallory's face.

"I can't let her go now without arraignment," the detective growled. "It ain't regular."

"You must let her go, Mr. Mallory," commanded The Thinking Machine, and over the woman's shoulder the detective saw an astonishing thing. The Thinking Machine winked. It was a decided, long, pronounced wink.

"Oh, all right," he said, "but it ain't regular at that."

The woman passed out of the room hurriedly, her silken skirts rustling loudly. She was free again. Immediately she disappeared The Thinking Machine's entire manner changed.

"Put your best man to follow her," he directed rapidly. "Let him go to her home and arrest the man who is with her as her husband. Then bring them both back here, after searching their rooms for money."

"Why--what--what is all this?" demanded Mallory, amazed.

"The man who inquired for her, who is with her, is wanted for a $175,000 embezzlement in Butte, Montana. Don't let your man lose sight of her."

The detective left the room hurriedly. Ten minutes later he returned to find The Thinking Machine leaning back in his chair with eyes upturned. Hatch and Doane were waiting, both impatiently.

"Now, Mr. Mallory," said the scientist, "I shall try to make this matter as clear to you as it is to me. By the time I finish I expect your man will be back here with this woman and the embezzler. His name is Harrison; I don't know hers. I can't believe she is Mrs. Harrison, yet he has, I suppose, a wife. But here's the story. It is the chaining together of fact after fact; a necessary logical sequence to a series of incidents, which are, separately, deeply puzzling."

The detective lighted a cigar and the others disposed themselves comfortably to listen.

"This gentleman came to me," began The Thinking Machine, "with a story of loss of memory. He told me that he knew neither his name, home, occupation, nor anything whatever about himself. At the moment it struck me as a case for a mental expert; still I was interested. It seemed to be a remarkable case of aphasia, and I so regarded it until he told me that he had $10,000 in bills, that he had no watch, that everything which might possibly be of value in establishing his identity had been removed from his clothing. This included even the names of the makers of his linen. That showed intent, deliberation.

"Then I knew it could _not_ be aphasia. That disease strikes a man suddenly as he walks the street, as he sleeps, as he works, but never gives any desire to remove traces of one's identity. On the contrary, a man is still apparently sound mentally--he has merely forgotten something--and usually his first desire is to find out who he is. This gentleman had that desire, and in trying to find some clew he showed a mind capable of grasping at every possible opportunity. Nearly every question I asked had been anticipated. Thus I recognized that he must be a more than usually astute man.

"But if not aphasia, what was it? What caused his condition? A drug? I remembered that there was such a drug in India, not unlike hasheesh. Therefore for the moment I assumed a drug. It gave me a working basis. Then what did I have? A man of striking mentality who was the victim of some sort of plot, who had been drugged until he lost himself, and in that way disposed of. The handwriting might be the same, for handwriting is rarely affected by a mental disorder; it is a physical function.

"So far, so good. I examined his head for a possible accident. Nothing. His hands were white and in no way calloused. Seeking to reconcile the fact that he had been a man of strong mentality, with all other things a financier or banker, occurred to me. The same things might have indicated a lawyer, but the poise of this man, his elaborate care in dress, all these things made me think him the financier rather than the lawyer.

"Then I examined some money he had when he awoke. Fifteen or sixteen of the hundred-dollar bills were new and in sequence. They were issued by a national bank. To whom? The possibilities were that the bank would have a record. I wired, asking about this, and also asked Mr. Hatch to have his correspondents make inquiries in various cities for a John Doane. It was not impossible that John Doane was his name. Now I believe it will be safe for me to say that when he registered at the hotel he was drugged, his own name slipped his mind, and he signed John Doane--the first name that came to him. That is _not_ his name.

"While waiting an answer from the bank I tried to arouse his memory by referring to things in the West. It appeared possible that he might have brought the money from the West with him. Then, still with the idea that he was a financier, I sent him to the financial district. There was a result. The word 'copper' aroused him so that he fainted after shouting, 'Sell copper, sell, sell, sell.'

"In a way my estimate of the man was confirmed. He was or had been in a copper deal, selling copper in the market, or planning to do so. I know nothing of the intricacies of the stock market. But there came instantly to me the thought that a man who would faint away in such a case must be vitally interested as well as ill. Thus I had a financier, in a copper deal, drugged as result of a conspiracy. Do you follow me, Mr. Mallory?"

"Sure," was the reply.

"At this point I received a telegram from the Butte bank telling me that the hundred-dollar bills I asked about had been burned. This telegram was signed 'Preston Bell, Cashier.' If that were true, the bills this man had were counterfeit. There were no ifs about that. I asked him if he knew Preston Bell. It was the only name of a person to arouse him in any way. A man knows his own name better than anything in the world. Therefore was it his? For a moment I presumed it was.

"Thus the case stood: Preston Bell, cashier of the Butte bank, had been drugged, was the victim of a conspiracy, which was probably a part of some great move in copper. But if this man were _Preston Bell_, how came the signature there? Part of the office regulation? It happens hundreds of times that a name is so used, particularly on telegrams.

"Well, this man who was lost--Doane, or Preston Bell--went to sleep in my apartments. At that time I believed it fully possible that he was a counterfeiter, as the bills were supposedly burned, and sent Mr. Hatch to consult an expert. I also wired for details of the fire loss in Butte and names of persons who had any knowledge of the matter. This done, I removed and examined this gentleman's shoes for the name of the maker. I found it. The shoes were of fine quality, probably made to order for him.

"Remember, at this time I believed this gentleman to be Preston Bell, for reasons I have stated. I wired to the maker or retailer to know if he had a record of a sale of the shoes, describing them in detail, to any financier or banker. I also wired to the Denver police to know if any financier or banker had been away from there for four or five weeks. Then came the somewhat startling information, through Mr. Hatch, that the hundred-dollar bills were genuine. That answer meant that Preston Bell--as I had begun to think of him--was either a thief or the victim of some sort of financial conspiracy."

During the silence which followed every eye was turned on the man who was lost--Doane or Preston Bell. He sat staring straight ahead of him with hands nervously clenched. On his face was written the sign of a desperate mental struggle. He was still trying to recall the past.

"Then," The Thinking Machine resumed, "I heard from the Denver police. There was no leading financier or banker out of the city so far as they could learn hurriedly. It was not conclusive, but it aided me. Also I received another telegram from Butte, signed Preston Bell, telling me the circumstances of the supposed burning of the hundred-dollar bills. It did not show that they were burned at all; it was merely an assumption that they had been. They were last seen in President Harrison's office."

"Harrison, Harrison, Harrison," repeated Doane.

"Vaguely I could see the possibility of something financially wrong in the bank. Possibly Harrison, even Mr. Bell here, knew of it. Banks do not apply for permission to reissue bills unless they are positive of the original loss. Yet here were the bills. Obviously some sort of jugglery. I wired to the police of Butte, asking some questions. The answer was that Harrison had embezzled $175,000 and had disappeared. Now I knew he had part of the missing, supposedly burned, bills with him. It was obvious. Was Bell also a thief?

"The same telegram said that Mr. Bell's reputation was of the best, and he was out of the city. That confirmed my belief that it was an office rule to sign telegrams with the cashier's name, and further made me positive that this man was Preston Bell. The chain of circumstances was complete. It was two and two--inevitable result, four.

"Now, what was the plot? Something to do with copper, and there was an embezzlement. Then, still seeking a man who knew Bell personally, I sent him out walking with Hatch. I had done so before. Suddenly another figure came into the mystery--a confusing one at the moment. This was a Mr. Manning, who knew Doane, or Bell, as Harry--something; met him in Pittsburg three years ago, in the Lincoln Club.

"It was just after Mr. Hatch told me of this man that I received a telegram from the shoemaker in Denver. It said that he had made a shoe such as I described within a few months for Preston Bell. I had asked if a sale had been made to a financier or banker; I got the name back by wire.

"At this point a woman appeared to claim John Doane as her husband. With no definite purpose, save general precaution, I asked Mr. Hatch to see her first. She imagined he was Doane and embraced him, calling him John. Therefore she was a fraud. She did not know John Doane, or Preston Bell, by sight. Was she acting under the direction of some one else? If so, whose?"

There was a pause as The Thinking Machine readjusted himself in the chair. After a time he went on:

"There are shades of emotion, intuition, call it what you will, so subtle that it is difficult to express them in words. As I had instinctively associated Harrison with Bell's present condition I instinctively associated this woman with Harrison. For not a word of the affair had appeared in a newspaper; only a very few persons knew of it. Was it possible that the stranger Manning was backing the woman in an effort to get the $10,000? That remained to be seen. I questioned the woman; she would say nothing. She is clever, but she blundered badly in claiming Mr. Hatch for a husband."

The reporter blushed modestly.

"I asked her flatly about a drug. She was quite calm and her manner indicated that she knew nothing of it. Yet I presume she did. Then I sprung the bombshell, and she saw she had made a mistake. I gave her over to Detective Mallory and she was locked up. This done, I wired to the Lincoln Club in Pittsburg to find out about this mysterious 'Harry' who had come into the case. I was so confident then that I also wired to Mrs. Bell in Butte, presuming that there was a Mrs. Bell, asking about her husband.

"Then Manning came to see me. I knew he came because he had remembered the name he knew you by," and The Thinking Machine turned to the central figure in this strange entanglement of identity, "although he seemed surprised when I told him as much. He knew you as Harry Pillsbury. I asked him who the woman was. His manner told me that he knew nothing whatever of her. Then it came back to her as an associate of Harrison, your enemy for some reason, and I could see it in no other light. It was her purpose to get hold of you and possibly keep you a prisoner, at least until some gigantic deal in which copper figured was disposed of. That was what I surmised.

"Then another telegram came from the Lincoln Club in Pittsburg. The name of Harry Pillsbury appeared as a visitor in the book in January, three years ago. It was you--Manning is not the sort of man to be mistaken--and then there remained only one point to be solved as I then saw the case. That was an answer from Mrs. Preston Bell, if there was a Mrs. Bell. She would know where her husband was."

Again there was silence. A thousand things were running through Bell's mind. The story had been told so pointedly, and was so vitally a part of him, that semi-recollection was again on his face.

"That telegram said that Preston Bell was in Honolulu; that the wife had received a cable dispatch that day. Then, frankly, I was puzzled; so puzzled, in fact, that the entire fabric I had constructed seemed to melt away before my eyes. It took me hours to readjust it. I tried it all over in detail, and then the theory which would reconcile every fact in the case was evolved. That theory is right--as right as that two and two make four. It's logic."

It was half an hour later when a detective entered and spoke to Detective Mallory aside.

"Fine!" said Mallory. "Bring 'em in."

Then there reappeared the woman who had been a prisoner and a man of fifty years.

"Harrison!" exclaimed Bell, suddenly. He staggered to his feet with outstretched hands. "Harrison! I know! I know!"

"Good, good, very good," said The Thinking Machine.

Bell's nervously twitching hands were reaching for Harrison's throat when he was pushed aside by Detective Mallory. He stood pallid for a moment, then sank down on the floor in a heap. He was senseless. The Thinking Machine made a hurried examination.

"Good!" he remarked again. "When he recovers he will remember everything except what has happened since he has been in Boston. Meanwhile, Mr. Harrison, we know all about the little affair of the drug, the battle for new copper workings in Honolulu, and your partner there has been arrested. Your drug didn't do its work well enough. Have you anything to add?"

The prisoner was silent.

"Did you search his rooms?" asked The Thinking Machine of the detective who had made the double arrest.

"Yes, and found this."

It was a large roll of money. The Thinking Machine ran over it lightly--$70,000--scanning the numbers of the bills. At last he held forth half a dozen. They were among the twenty-seven reported to have been burned in the bank fire in Butte.

Harrison and the woman were led away. Subsequently it developed that he had been systematically robbing the bank of which he was president for years; was responsible for the fire, at which time he had evidently expected to make a great haul; and that the woman was not his wife. Following his arrest this entire story came out; also the facts of the gigantic copper deal, in which he had rid himself of Bell, who was his partner, and had sent another man to Honolulu in Bell's name to buy up options on some valuable copper property there. This confederate in Honolulu had sent the cable dispatches to the wife in Butte. She accepted them without question.

It was a day or so later that Hatch dropped in to see The Thinking Machine and asked a few questions.

"How did Bell happen to have that $10,000?"

"It was given to him, probably, because it was safer to have him rambling about the country, not knowing who he was, than to kill him."

"And how did he happen to be here?"

"That question may be answered at the trial."

"And how did it come that Bell was once known as Harry Pillsbury?"

"Bell is a director in United States Steel, I have since learned. There was a secret meeting of this board in Pittsburg three years ago. He went incog. to attend that meeting and was introduced at the Lincoln Club as Harry Pillsbury."

"Oh!" exclaimed Hatch.

With a little laugh of sheer light-heartedness on her lips and a twinkle in her blue eyes, Marguerite Melrose bound on a grotesque automobile mask, and stuffed the last strand of her recalcitrant hair beneath her veil. The pretty face was hidden from mouth to brow; and her curls were ruthlessly imprisoned under a cap held in place by the tightly tied veil.

"It's perfectly hideous, isn't it?" she demanded of her companions.

Jack Curtis laughed.

"Well," he remarked, quizzically, "it's just as well that we _know_ you are pretty."

"We could never discover it as you are now," added Charles Reid. "Can't see enough of your face to tell whether you are white or black."

The girl's red lips were pursed into a pout, which ungraciously hid her white teeth, as she considered the matter seriously.

"I think I'll take it off," she said at last.

"Don't," Curtis warned her. "On a good road The Green Dragon only hits the tall places."

"Tear your hair off," supplemented Reid. "When Jack lets her loose it's just a pszzzzt!--and wherever you're going you're there."

"Not on a night as dark as this?" protested the girl, quickly.

"I've got lights like twin locomotives," Curtis assured her, smilingly. "It's perfectly safe. Don't get nervous."

He tied on his own mask with its bleary goggles, while Reid did the same. The Green Dragon, a low, gasoline car of racing build, stood panting impatiently, awaiting them at a side door of the hotel. Curtis assisted Miss Melrose into the front seat and climbed in beside her, while Reid sat behind in the tonneau. There was a preparatory quiver, the car jerked a little and then began to move.

The three persons in it were Marguerite Melrose, an actress who had attracted attention in the West five years before by her great beauty and had afterwards, by her art, achieved a distinct place; Jack Curtis, a friend since childhood, when both lived in San Francisco and attended the same school, and Charles Reid, his chum, son of a mine owner at Denver.

The unexpected meeting of the three in Boston had been a source of mutual pleasure. It had been two years since they had seen one another in Denver, where Miss Melrose was playing. Now she was in Boston, pursuing certain vocal studies before returning West for her next season.

Reid was in Boston to lay siege to the heart of a young woman of society, Miss Elizabeth Dow, whom he first met in San Francisco. She was only nineteen years old, but despite this he had begun a siege and his ardor had never cooled, even after Miss Dow returned East. In Boston, he had heard, she looked with favor upon another man, Morgan Mason, poor but of excellent family, and frantically Reid had rushed, like Lochinvar out of the West, to find the rumor true.

Curtis was one who never had anything to do save seek excitement in a new and novel way. He had come East with Reid. They had been together constantly since their arrival in Boston. He was of a different type from Reid in that his wealth was distinctly a burden, a thing which left him with nothing to do, and opened illimitable possibilities of dissipation. The pace he led was one which caused other young men to pause and think.

Warm-hearted and perfectly at home with both Curtis and Reid, Miss Melrose, the actress, frequently took occasion to scold them. It was charming to be scolded by Miss Melrose, so much so in fact that it was worth while sinning again. Since she had appeared on the horizon Curtis had devoted a great deal of time to her; Reid had his own difficulties trying to make Miss Dow change her mind.

The Green Dragon with its three passengers ran slowly down from the Hotel Yarmouth, where Miss Melrose was stopping, toward the Common, twisting and winding tortuously through the crowd of vehicles. It was half-past six o'clock in the evening.

"Cut across here to Commonwealth Avenue," Miss Melrose suggested. She remembered something and her bright blue eyes sparkled beneath the disfiguring mask. "I know a delightful old-fashioned inn out this way. It would be an ideal place to stop for supper. I was there once five years ago when I was in Boston."

"How far?" asked Reid.

"Fifteen or twenty miles," was the reply.

"Right," said Curtis. "Here we go."

Soon after they were skimming along Commonwealth Avenue, which at that time of day is practically given over to automobilists, past the Vendome, the Somerset and on over the flat, smooth road. It was perfectly light now, because the electric lights were about them; but there was no moon above, and once in the country it would be dark going.

Curtis was intent on his machine; Reid was thoughtful for a time, but after awhile leaned over and talked to Miss Melrose.

"I heard something to-day that might interest you," he remarked.

"What is it?" she asked.

"Don MacLean is in Boston."

"I heard that," she replied, casually.

"Who is he?" asked Curtis.

"A man who is frantically in love with Marguerite," said Reid, with a smile.

"Charlie!" the girl reproved, and a flush crept into her face. "It was never anything very serious."

Curtis looked at her curiously for a moment, then his eyes turned again to the road ahead.

"I don't suppose it's very serious if a man proposes to a girl seven times, is it?" Reid asked, banteringly.

"Did he do that?" asked Curtis, quickly.

"He merely made a fool of himself and me," replied the actress, with spirit, speaking to Curtis. "He was--in love with me, I suppose, but his family objected because I was on the stage and threatened to disinherit him, and all that sort of thing. So--it ended it. Not that I ever considered the matter seriously anyway," she added.

There was silence again as The Green Dragon plunged into the darkness of the country, the two brilliant lights ahead showing every dip and rise in the road. After awhile Curtis spoke again.

"He's now in Boston?"

"Yes," said the girl. "At least, I've heard so," she added, quickly.

Then the conversation ran into other channels, and Curtis, busy with the great machine and the innumerable levers which made it do this or do that or do the other, dropped out of it. Reid and Miss Melrose talked on, but the whirr of the car as it gained speed made talking unsatisfactory and finally the girl gave herself up to the pure delight of high speed; a dangerous pleasure which sets the nerves atingle and makes one greedy for more.

"Do you smell gasoline?" Curtis asked suddenly, turning to the others.

"Believe I do," said Reid.

"Confound it! If I've sprung a leak in my tank it will be the deuce," Curtis growled amiably.

"Do you think you've got enough to get to the inn?" asked Miss Melrose. "It can't be more than five or six miles now."

"I'll run on until we stop," said Curtis. "We might be able to stir up some along here somewhere. I suppose they are prepared for autos."

At last lights showed ahead, many lights glimmering through the trees.

"I suppose that's the inn now," said Curtis. "Is it?" he asked of the girl.

"Really, I don't know, but I have an impression that it isn't. The one I mean seems farther out than this and it seems to me we passed one on the way. However, I don't remember very well."

"We'll stop and get some gasoline, anyhow," said Curtis.

Puffing and snorting odorously The Green Dragon came to a standstill in front of an old house which stood back twenty feet or more from the road. It was lighted up, and from inside they could hear the cheery rattle of dishes and see white-aproned waiters moving about. Above the door was a sign, "Monarch Inn."

"Is this the place?" asked Reid.

"Oh, no," replied Miss Melrose. "The inn I spoke of was back from the road three or four hundred feet through a grove."

Curtis leaped out, and evidently dropped something from his pocket as he did so, for he stopped and felt around for a moment. Then he examined his tank.

"It's a leak," he said, in irritation. "I haven't more than half a gallon left. These people must have some gasoline. Wait a few minutes."

Miss Melrose and Reid still sat in the car as he started away toward the house. Almost at the veranda he turned and called back:

"Charlie, I dropped something there when I jumped out. Get down and strike a match and see if you can find it. Don't go near that gasoline tank with the match."

He disappeared inside the house. Reid climbed out and struck several matches. Finally he found what was lost and thrust it into an outside pocket. Miss Melrose was gazing away down the road at two brilliant lights coming toward them rapidly.

"Rather chilly," Reid said, as he straightened up. "Want a cup of coffee or something?"

"Thanks, no," the girl replied.

"I think I'll run in and scare up some sort of a hot drink, if you'll excuse me?"

"Now, Charlie, don't," the girl asked, suddenly. "I don't like it."

"Oh, one won't hurt," he replied, lightly.

"I shan't speak to you when you come out," she insisted, half banteringly.

"Oh, yes, you will." He laughed, and passed into the house.

Miss Melrose tossed her pretty head impatiently and turned to watch the approaching lights. They were blinding as they drew nearer, clearly revealing her figure, in its tan auto coat, to the occupant of the other car. The newcomer stopped and then she heard whoever was in it--she couldn't see--speaking to her.

"Would you mind turning your car a little so I can run in off the road?"

"I don't know how," she replied, helplessly.

There was a little pause. The occupant of the other car was leaning forward, looking at her closely.

"Is that you, Marguerite?" he asked finally.

"Yes," she replied. "Who is that? Don?"

"Yes."

A man's figure leaped out of the other machine and came toward her.

* * * * *

Curtis appeared beside The Green Dragon with a huge can of gasoline twenty minutes later. The two occupants of the car were clearly silhouetted against the sky, and Reid, leaning back in the tonneau, was smoking.

"Find it?" he asked.

"Yes," growled Curtis. And he began the work of repairing the leak and refilling his tank. It took only five minutes or so, and then he climbed up into the car.

"Cold, Marguerite?" he asked.

"She won't speak," said Reid, leaning forward a little. "She's angry because I went inside to get a hot Scotch."

"Wish I had one myself," said Curtis.

"Let's wait till we get to the next place," Reid interposed. "A little supper and trimmings will put all of us in a better humor."

Without answering, Curtis threw a lever, and the car pulled out. Two automobiles which had been standing when they arrived were still waiting for their owners. Annoyed at the delay, Curtis put on full speed. Finally Reid leaned forward and spoke to the girl.

"In a good humor?" he asked.

She gave no sign of having heard, and Reid placed his hand on her shoulder as he repeated the question. Still there was no answer.

"Make her talk to you, Jack," he suggested to Curtis.

"What's the matter, Marguerite?" asked Curtis, as he glanced around.

Still there was no answer, and he slowed up the car a little. Then he took her arm and shook it gently. There was no response.

"What _is_ the matter with her?" he demanded. "Has she fainted?"

Again he shook her, this time more vigorously than before.

"Marguerite," he called.

Then his hand sought her face; it was deathly cold, clammy even about the chin. The upper part was still covered by the mask. For the third time he shook her, then, really frightened, apparently, he caught at her gloved wrist and brought the car to a standstill. There was no trace of a pulse; the wrist was cold as death.

"She must be ill--very ill," he said in some agitation. "Is there a doctor near here?"

Reid was leaning over the senseless body now, having raised up in the tonneau, and when he spoke there seemed to be fear in his tone.

"Better run on as fast as you can to the inn ahead," he instructed Curtis. "It's nearer than the one we just left. There may be a doctor there."

Curtis grabbed frantically at the lever and the car shot ahead suddenly through the dark. In three minutes the lights of the second inn were in sight. The two men leaped from the car simultaneously and raced for the house.

"A doctor, quick," Curtis breathlessly demanded of a waiter.

"Next door."

Without waiting for further instructions, Curtis and Reid ran to the auto, lifted the girl in their arms and took her to a house which stood just a few feet away. There, after much clamoring, they aroused some one. Was the doctor in? Yes. Would he hurry? Yes.

The door opened and the men laid the girl's body on a couch in the hall. Dr. Leonard appeared. He was an old fellow, grizzled, with keen, kindly eyes and rigid mouth.

"What's the matter?" he asked.

"Think she's dead," replied Curtis.

The doctor adjusted his glasses rather hurriedly.

"Who is she?" he asked, as he bent over the still figure and fumbled about the throat and breast.

"Miss Marguerite Melrose, an actress," explained Curtis, hurriedly.

"What's the matter with her?" demanded Reid, fiercely.

The doctor still bent over the figure. In the dim lamplight Curtis and Reid stood waiting anxiously, impatiently, with white faces. At last the doctor straightened up.

"What is it?" demanded Curtis.

"She's dead," was the reply.

"Great God!" exclaimed Reid. "How?" Curtis seemed speechless.

"This," said the doctor, and he exhibited a long knife, damp with blood. "Stabbed through the heart."

Curtis stared at him, at the knife, then at the inert figure, and lastly at the dead white of her face where it showed beneath the mask.

"Look, Jack!" exclaimed Reid, suddenly. "The knife!"

Curtis looked again, then sank down on the couch beside the body.

"Oh, my God! It's horrible!" he said.

To Hutchinson Hatch and half a dozen other reporters, Dr. Leonard, at his home late that night, told the story of the arrival of Jack Curtis and Charles Reid with the body of the girl, and the succeeding events so far as he knew them. The police and Medical Examiner Francis had preceded the newspaper men, and the body had been removed to a nearby village.

"They came here in great excitement," Dr. Leonard explained. "They brought the body in with them, the man Curtis lifting her by the shoulders and the man Reid at the feet. They placed the body on this couch. I asked them who she was, and they told me she was Marguerite Melrose, an actress. That's all that was said of her identity.

"Then I made an examination of the body, seeking a trace of life. There was none, although the body was not then entirely cold. In examining her heart my hand struck the knife which had killed her--a heavy weapon, evidently used for rough work, with a blade of six or seven inches. I drew the knife out. Of course, knowing that it had pierced her heart, any idea of doing anything to save her was beyond question.

"One of the men, Curtis, seemed greatly excited about this knife after Reid called his attention to it. Curtis took the knife out of my hand and examined it closely, then asked if he might keep it. I told him it would have to be turned over to the medical examiner. He argued about it, and finally, to settle the argument, I took it out of his hand. Reid explained to Curtis that it was necessary for me to keep the knife, and finally Curtis seemed to agree to it.

"Then I suggested that the police be notified. I did this myself by telephone, the men remaining with me all the time. I asked if they could throw any light on the tragedy, but neither could. Curtis said he had been out searching for a man who had the keys to a shed where some gasoline was locked up, and it took fifteen or twenty minutes to find him. As soon as he got the gasoline he returned to the auto.

"Reid and Miss Melrose were at this time in the auto, he said. What had happened while he had been away Curtis didn't know. Reid said he, too, had stepped out of the automobile, and after exchanging a few words with Miss Melrose went into the inn. There he remained fifteen minutes or so, because inside he saw a woman he knew and spoke to her. He declared that any one of three waiters could verify his statement that he was in the Monarch Inn.

"After I had notified the police Curtis grew very uneasy in his actions--it didn't occur to me at the moment, but now I recall that it was so--and suggested to Reid that they go on to Boston and send out detectives--special Pinkerton men. I tried to dissuade them, but they went away. I couldn't stop them. They gave me their cards, however. They are at the Hotel Teutonic, and told me they could be seen there at any time. The medical examiner and the police came afterwards. I told them, and one of the detectives started immediately for Boston. They have probably told their story to him by this time."

"What did the young woman look like?" asked Hatch.

"Really, I couldn't say," said the doctor. "She wore an automobile mask which covered all her face except the chin, and there was a veil tied over her cap, concealing her hair. I didn't remove these; I left the body just as it was for the medical examiner."

"How was she dressed?" Hatch went on.

"She wore a long tan automobile dust coat of what seemed to be rich material, and beneath this a handsome--not a fancy--gown. I believe it was tailor-made. She was a woman of superb figure."

That was all that could be learned from Dr. Leonard, and Hatch and the other men raced back to Boston. The next day the newspapers flamed with the mystery of the murder of Miss Melrose, a beautiful Western actress who was visiting Boston. Each newspaper watched the other greedily to see if there was a picture of Miss Melrose; neither had one.

The newspapers also carried the stories of Jack Curtis and Charles Reid in connection with the murder. The stories were in substance just what Dr. Leonard had said, but were given in more detail. It was the general presumption, almost a foregone conclusion, that some one had killed Miss Melrose while the two men were away from the auto.

Who was this some one? Man or woman? No one could answer. Reid's story of being inside the Monarch Inn, where he spoke to a lady he knew--but whose name he refused to give--was verified by Hatch's paper. Three waiters had seen him.

The medical examiner had made only a brief statement, in which he had said, in answer to a question, that the person who killed Miss Melrose might have been either at her right, in the position Curtis would have occupied while driving the car, or might have leaned forward from behind and stabbed her. Thus it was not impossible that one of the men in the car with her had killed her, yet against this possibility was the fact that each of the men was one whom one could not readily associate with such a crime.

The fact that the fatal blow was delivered from the right was proven, said the astute medical examiner, by the fact that the knife slanted as a knife could not have been slanted conveniently by a person on her other side--her left. There were many dark, underlying intimations behind what the medical man said; but he refused to say any more. Meanwhile the body remained in the village where it had been taken. Efforts to get a photograph were unavailing; pleas of newspaper artists for permission to sketch her fell upon deaf ears.

Curtis and Reid, after their first statements, remained in seclusion at the Teutonic. They were not arrested because this did not seem necessary. Both had offered to do anything in their power to solve the riddle, had even employed Pinkerton men who were now on the case; but they would say nothing nor see anyone except the police. The police encouraged them in this attitude, and hinted darkly and mysteriously at clews which "would lead to an arrest within twenty-four hours."

Hatch read these intimations and smiled grimly. Then he went out to try what a little patience and perseverance and human intelligence would do. He learned something of Reid's little romance in Boston. Yet not all of it. It was a fact, however, that Reid had called at the home of Miss Elizabeth Dow on Beacon Hill just after noon and inquired for her.

"She is not in," the maid had replied.

"I'll leave my card for her," said Reid.

"I don't think she'll be back," the girl answered.

"Not be back?" Reid repeated. "Why?"

"Haven't you seen the afternoon papers?" asked the girl. "They will explain. Mrs. Dow, her mother, told me not to talk to anyone."

Reid left the house with a wrinkle in his brow and walked on toward the Common. There he halted a newsboy and bought an afternoon paper--many afternoon papers. The first pages were loaded with details of the murder of Miss Melrose, theories, conjectures, a thousand little things, with long dispatches of her history and her stage career from San Francisco.

Reid passed these over impatiently with a slight shiver and looked inside the paper. There he found the thing to which the maid had referred.

"By George!" he exclaimed.

It was a story of the elopement of Elizabeth Dow with Morgan Mason, Reid's rival. It seemed that Miss Dow and Mason met by appointment at the Monarch Inn and went from there in an automobile. The bride had written to her parents before she started, saying she preferred Mason despite his poverty. The family refused to talk of the matter. But there in facsimile was the marriage license.

Reid's face was a study as he walked back to the hotel. In a private room off the café he found Curtis, who had been drinking heavily, yet who, with the strange mood of some men, was not visibly intoxicated. Reid threw the paper down, open at the elopement announcement.

"See that," he said shortly.

Curtis read it--or glanced at it--but did not make a remark until he came to the name, the Monarch Inn. Then he looked up.

"That's where the other thing happened, isn't it?" he asked, rather thickly.

"Yes."

Curtis rambled off into something else; studiously he avoided any reference to the tragedy, yet that was the one thing which was in his mind. It was in a futile effort to forget it that he was drinking now. He talked on as a drunken man will for a time, then turned suddenly to Reid.

"I loved her," he declared suddenly, passionately. "My God!"

"Try not to think of it," Reid advised.

"You'll never say anything about that other thing--the knife--will you?" pleaded Curtis.

"Of course not," said Reid, impatiently. "They couldn't drag it out of me. But you're drinking too much--you want to quit it. First thing you know you'll be saying more than--get up and go out and take a walk."

Curtis stared at Reid vacantly for a moment, as if not understanding, then arose. He had regained possession of himself to a certain extent. but his face was pale.

"I think I will go out," he said.

After a time he passed through the café door into a side street and, refreshed a little by the cool air, started to walk along Tremont Street toward the shopping district. It was two o'clock in the afternoon and the streets were thronged.

Half a dozen reporters were idling in the lobby of the hotel, waiting vainly for either Reid or Curtis. The newspapers were shouting for another story from the only two men who could know a great deal of the circumstances attending the tragedy. Reid, on his return, had marched boldly through the crowd of reporters, paying no attention to their questions. They had not seen Curtis.

As Curtis, now free of the reporters, crossed a side street off Tremont on his way toward the shopping district he met Hutchinson Hatch, who was bound for the hotel to see his man there. Hatch instantly recognized him and fell in behind, curious to see where he would go. At a favorable opportunity, safe beyond reach of the other men, he intended to ask a few questions.

Curtis turned into Winter Street and strolled along through the crowd of women. Half way down Winter Street Hatch followed, and then for a moment he lost sight of him. He had gone into a store, he imagined. As he stood at a door waiting, Curtis came out, rushed through the crowd of women, slinging his arms like a madman, with frenzy in his face. He ran twenty steps, then stumbled and fell.

Hatch immediately ran to his assistance, lifted him up and gazed into the staring, terror-stricken eyes and an ashen face.

"What is it?" asked Hatch, quickly.

"I--I'm very ill. I--I think I need a doctor," gasped Curtis. "Take me somewhere, please."

He fell back limply, half fainting, into Hatch's arms. A cab came worming through the crowd; Hatch climbed into it, assisting Curtis, and gave some directions to the cabby.

"And hurry," he added. "This gentleman is ill."

The cabby applied the whip and drove out into Tremont, then over toward Park Street. Curtis aroused a little.

"Where're we going?" he demanded.

"To a doctor," replied Hatch.

Curtis sank back with eyes closed and his face white--so white that Hatch felt of the pulse to assure himself that the heart was still beating. After a few minutes the cab stopped and, still assisting Curtis, Hatch went to the door. An aged woman answered the bell.

"Professor Van Dusen here?" asked the reporter. "Yes."

"Please tell him that Mr. Hatch is here with a gentleman who needs immediate attention," Hatch directed, hurriedly.

He knew his way here and, still supporting Curtis, walked in. The woman disappeared. Curtis sank down on a couch in the little reception room, looked at Hatch glassily for a moment, then without a sound dropped back on the couch unconscious.

After a moment the door opened and there came in Professor Augustus S. F. X. Van Dusen, The Thinking Machine. He squinted inquiringly at Hatch, and Hatch waved his head toward Curtis.

"Dear me, dear me," exclaimed The Thinking Machine.

He leaned over the prostrate figure a moment, then disappeared into another room, returning with a hypodermic. After a few anxious minutes Curtis sat up straight. He stared at the two men with unseeing eyes, and in them was unutterable terror.

"_I saw her! I saw her!_" he screamed. "_There was a dagger in her heart. Marguerite!_"

Again he fell back unconscious. The Thinking Machine squinted at Hatch.

"The man's got delirium tremens," he snapped impatiently.

For fifteen minutes Hatch silently looked on as The Thinking Machine worked over the unconscious man. Once or twice Curtis moved uneasily and moaned slightly. Hatch had started to explain the situation to The Thinking Machine, but the irascible scientist glared at him and the reporter became silent. After ten or fifteen minutes The Thinking Machine turned to Hatch more genially.

"He'll be all right in a little while now," he said. "What is it?"

"Well, it's a murder," Hatch began. "Marguerite Melrose, an actress, was stabbed through the heart last night, and----"

"Murder?" interrupted The Thinking Machine. "Might it not have been suicide?"

"Might have been; yes," said the reporter, after a moment's pause. "But it appears to be murder."

"When you say it is murder," said The Thinking Machine, "you immediately give the impression that you were there and saw it. Go on."

From the beginning, then, Hatch told the story as he knew it; of the stopping of The Green Dragon at the Monarch Inn, of the events there, of the whereabouts of Curtis and Reid at the time the girl received the knife thrust and of the confirmation of Reid's story. Then he detailed those incidents of the arrival of the men with the girl at Dr. Leonard's house, of what had transpired there, of the effort Curtis had made to get possession of the knife.

With finger tips pressed together and squinting steadily upward, The Thinking Machine listened. At its end, which bore on the actions of Curtis just preceding his appearance in the room with them, The Thinking Machine arose and walked over to the couch where Curtis lay. He ran his slender fingers idly through the unconscious man's thick hair several times.

"Doesn't it strike you as perfectly possible, Mr. Hatch," he asked finally, "that Miss Melrose _did_ kill herself?"

"It may be perfectly possible, but it doesn't appear so," said Hatch. "There was no motive."

"And certainly you've shown no motive for anything else," said the other, crustily. "Still," he mused, "I really can't say anything until I talk to him."

He again turned to his patient, and as he looked saw the red blood surge back into the face.

"Ah, now we're all right," he announced.

Thus it happened, for after another ten minutes the patient sat up suddenly on the couch and looked at the two men before him, bewildered.

"What's the matter?" he asked. The thickness was gone from his speech; he was himself again, although a little shaky.

Briefly, Hatch explained to him what had happened, and he listened silently. Finally he turned to The Thinking Machine.

"And this gentleman?" he asked. He noted the queer appearance of the scientist, and stared into the squint eyes frankly.

"Professor Van Dusen, a distinguished scientist and physician," Hatch introduced. "I brought you here. He has been working with you for an hour."

"And now, Mr. Curtis," said The Thinking Machine, "if you will tell us _all_ you know about the murder of Miss Melrose----"

Curtis paled suddenly.

"Why do you ask me?" he demanded.

"You said a great deal while you were unconscious," remarked The Thinking Machine, as he dreamily stared at the ceiling. "I know that worry over that and too much alcohol have put you in a condition bordering on nervous collapse. I think it would be better if you told it _all_."

Hatch instantly saw the trend of the scientist's remarks, and remained discreetly silent. Curtis stared at both for a moment, then paced nervously across the room. He did not know what he might have said, what chance word might have been dropped. Then, apparently, he made up his mind, for he stopped suddenly in front of The Thinking Machine.

"Do I look like a man who would commit murder?" he asked.

"No, you do not," was the prompt response. His recital of the story was similar to that of Hatch, but the scientist listened carefully.

"Details! details!" he interrupted once.

The story was complete from the moment Curtis jumped out of the car until the return to the hotel of Curtis and Reid. There the narrator stopped.

"Mr. Curtis, why did you try to induce Dr. Leonard to give up the knife to you?" asked The Thinking Machine, finally.

"Because--well, because----" He faltered, flushed and stopped.

"Because you were afraid it would bring the crime home to you?" asked the scientist.

"I didn't know _what_ might happen," was the response.

"Is it your knife?"

Again the tell-tale flush overspread Curtis's face.

"No," he said, flatly.

"Is it Reid's knife?"

"Oh, no," he said, quickly.

"You were in love with Miss Melrose?"

"Yes," was the steady reply.

"Had she ever refused to marry you?"

"I had never asked her."

"Why?"

"Is this a third degree?" demanded Curtis, angrily, and he arose. "Am I a prisoner?"

"Not at all," said The Thinking Machine, quietly. "You may be made a prisoner, though, on what you said while unconscious. I am merely trying to help you."

Curtis sank down in a chair with his head in his hands and remained motionless for several minutes. At last he looked up.

"I'll answer your questions," he said.

"Why did you never ask Miss Melrose to marry you?"

"Because--well, because I understood another man, Donald MacLean, was in love with her, and she might have loved him. I understood she would have married him had it not been that by doing so she would have caused his disinheritance. MacLean is now in Boston."

"Ah!" exclaimed The Thinking Machine. "Your friend Reid didn't happen to be in love with her, too, did he?"

"Oh, no," was the reply. "Reid came here hoping to win the love of Miss Dow, a society girl. I came with him."

"Miss Dow?" asked Hatch, quickly. "The girl who eloped last night with Morgan Mason?"

"Yes," replied Curtis. "That elopement and this--crime have put Reid almost in as bad a condition as I am."

"What elopement?" asked The Thinking Machine.

Hatch explained how Mason had procured a marriage license, how Miss Dow and Mason had met at the Monarch Inn--where Miss Melrose must have been killed according to all stories--how Miss Dow had written to her parents from there of the elopement and then of their disappearance. The Thinking Machine listened, but without apparent interest.

"Have you such a knife as was used to kill Miss Melrose?" he asked at the end.

"No."

"Did you ever have such a knife?"

"Well, once."

"Where did you carry it when it was not in your auto kit?"

"In my lower coat pocket."

"By the way, what kind of looking woman was Miss Melrose?"

"One of the most beautiful women I ever met," said Curtis, with a certain enthusiasm. "Of ordinary height, superb figure--a woman who would attract attention anywhere."

"I believe she wore a veil and an automobile mask at the time she was killed?"

"Yes. They covered all her face except her chin."

"Could she, wearing an automobile mask, see either side of herself without turning?" asked The Thinking Machine, pointedly. "Had you intended to stab her, say while the car was in motion and had the knife in your hand, even in daylight, could she have seen it without turning her head? Or, if she had had the knife, could you have seen it?"

Curtis shuddered a little.

"No, I don't believe so."

"Was she blonde or brunette?"

"Blonde, with great clouds of golden hair," said Curtis, and again there was admiration in his tone.

"Golden hair?" Hatch repeated. "I understood Medical Examiner Francis to say she had dark hair?"

"No, golden hair," was the positive reply.

"Did you see the body, Mr. Hatch?" asked the scientist.

"No. None of us saw it. Dr. Francis makes that a rule."

The Thinking Machine arose, excused himself and passed into another room. They heard the telephone bell ring and then some one closed the door connecting the two rooms. When the scientist returned he went straight to a point which Hatch had impatiently awaited.

"What happened to you this afternoon in Winter Street?"

Curtis had retained his composure well up to this point; now he became uneasy again. Quick pallor on his face was succeeded by a flush which crept up to the roots of his hair.

"I've been drinking too much," he said at last. "That and this thing have completely unnerved me. I am afraid I was not myself."

"What did you _think_ you saw?" insisted The Thinking Machine.

"I went into a store for something. I've forgotten what now. I know there was a great crowd of women--they were all about me. There I saw--" He stopped and was silent for a moment. "There I saw," he went on with an effort, "a woman--just a glimpse of her, over the heads of the others in the store--and----"

"And what?" insisted The Thinking Machine. "At the moment I would have sworn it was Marguerite Melrose," was the reply.

"Of course you know you were mistaken?"

"I know it now," said Curtis. "It was a chance resemblance, but the effect on me was awful. I ran out of there shrieking--it seemed to me. Then I found myself here."

"And you don't know what you said or did from that time until the present?" asked the scientist, curiously.

"No, except in a hazy sort of way."

After awhile Martha, the scientist's aged servant, appeared in the doorway.

"Mr. Mallory and a gentleman, sir."

"Let them come in," said The Thinking Machine. "Mr. Curtis," and he turned to him gravely, "Mr. Reid is here. I sent for him as if at your request to ask him two questions. If he answers those questions, as I believe he will, I can demonstrate that you are not guilty of and have no connection with the murder of Miss Melrose. Let me ask these questions, without any hint or remark from you as to what the answer must be. Are you willing?"

"I am," replied Curtis. His face was white, but his voice was firm.

Detective Mallory, whom Curtis didn't know, and Charles Reid entered the room. Both looked about curiously. Mallory nodded brusquely at Hatch. Reid looked at Curtis and Curtis looked away.

"Mr. Reid," said The Thinking Machine, without any preliminary, "Mr. Curtis tells me that the knife used to kill Miss Melrose was your property. Is that so?" he demanded quickly, as Curtis faced about wonderingly.

"No," thundered Reid, fiercely. "Is it Mr. Curtis's knife?" asked The Thinking Machine.

"Yes," flashed Reid. "It's a part of his auto kit."

Curtis started to speak; The Thinking Machine waved his hand toward him. Detective Mallory caught the gesture and understood that Jack Curtis was his prisoner for murder.

Curtis was led away and locked up. He raved and bitterly denounced Reid for the information he had given, but he did not deny it. Indeed, after the first burst of fury he said nothing.

Once he was under lock and key the police, led by Detective Mallory, searched his rooms at the Hotel Teutonic and there they found a handkerchief stained with blood. It was slight, still it was a stain. This was immediately placed in the hands of an expert, who pronounced it human blood. Then the case against Curtis seemed complete; it was his knife, he had been in love with Miss Melrose, therefore probably jealous of her, and here was the tell-tale bloodstain.

Meanwhile Reid was permitted to go his way. He seemed crushed by the rapid sequence of events, and read eagerly every line he could find in the public prints concerning both the murder and the elopement of Miss Dow. This latter affair, indeed, seemed to have greater sway over his mind than the murder, or that a lifetime friend was now held as the murderer.

Meanwhile The Thinking Machine had signified to Hatch his desire to visit the scene of the crime and see what might be done there. Late in the afternoon, therefore, they started, taking a train for a village nearest the Monarch Inn.

"It's a most extraordinary case," The Thinking Machine said, "much more extraordinary than you can imagine."

"In what respect?" asked the reporter.

"In motive, in the actual manner of the girl meeting her death and in a dozen other details which I can't state now because I haven't all the facts."

"You don't doubt but what it was murder?"

"It doesn't necessarily follow," said The Thinking Machine, evasively. "Suppose we were seeking a motive for Miss Melrose's suicide, what would we have? We would have her love affair with this man MacLean whom she refused to marry because she knew he would be disinherited. Suppose she had not seen him for a couple of years--suppose she had made up her mind to give him up--that he had suddenly appeared when she sat alone in the automobile in front of the Monarch Inn--suppose, then, finding all her love reawakened, she had decided to end it all?"

"But Curtis's knife and the blood on his handkerchief?"

"Suppose, having made up her mind to kill herself, she had sought a weapon?" went on The Thinking Machine, as if there had been no interruption. "What is more natural than she should have sought something--the knife, say--in the tool bag or kit, which must have been near her? Suppose she stabbed herself while the men were away from the automobile, or even after they had started on again in the darkness?"

Hatch looked a little crestfallen.

"You believe, then, that she did kill herself?" he asked.

"Certainly not," was the prompt response. "I don't believe Miss Melrose killed herself--but as yet I know nothing to the contrary. As for the blood on Curtis's handkerchief, remember he helped carry the body to Dr. Leonard; it might have come from that--it might have come from a slight spattering of blood."

"But circumstances certainly implicate Curtis."

"I wouldn't convict any man of any crime on any circumstantial evidence," was the response. "It's worthless unless a man is forced to confess."

The reporter was puzzled, bewildered, and his face showed it. There were many things he did not understand, but the principal question in his mind took form:

"Why did you turn Curtis over to the police, then?"

"Because he is the man who owned the knife," was the reply. "I knew he was lying to me from the first about the knife. Men have been executed on less evidence than that."

The train stopped and they proceeded to the office of the medical examiner, where the body of the woman lay. Professor Van Dusen was readily permitted to see the body, even to offer his expert assistance in an autopsy which was then being performed; but the reporter was stopped at the door. After an hour The Thinking Machine came out.

"She was stabbed from the right," he said in answer to Hatch's inquiring look, "either by some one sitting at her right, by some one leaning over her right shoulder, or she might have done it herself."

Then they went on to Monarch Inn, five miles away. Here, after a comprehensive squint at the landscape, The Thinking Machine entered and for half an hour questioned three waiters there.

Did these waiters see Mr. Reid? Yes. They identified his published picture as a gentleman who had come in and taken a hot Scotch at the bar. Any one with him? No. Speak to anyone in the inn? Yes, a lady.

"What did she look like?" asked The Thinking Machine.

"Couldn't say, sir," the waiter replied. "She came in an automobile and wore a mask, with a veil tied about her head and a long tan automobile coat."

"With the mask on you couldn't see her face?"

"Only her chin, sir."

"No glimpse of her hair?"

"No, sir. It was covered by the veil."

Then The Thinking Machine turned loose a flood of questions. He learned that the woman had been waiting at the inn for nearly an hour when Reid entered; that she had come there alone and at her request had been shown into a private parlor--"to wait for a gentleman," she had told the waiter.

She had opened the door when she heard Reid enter and had glanced out, but he had disappeared into the bar before she saw him. When he started away she looked out again. Then she saw him and he saw her. She seemed surprised and started to close the door, when he spoke to her. No one heard what was said, but he went in and the door was closed.

No one knew just when either Reid or the woman left the inn. Some half an hour or so after Reid entered the room a waiter rapped on the door. There was no answer. He opened the door and went in, but there was no one there. It was presumed then that the gentleman she had been waiting for had appeared and they had gone out together. It was a fact that an automobile had come up meanwhile--in addition to that in which Curtis, Miss Melrose and Reid had come--and had gone away again.

When all this questioning had come to an end and these facts were in possession of The Thinking Machine, the reporter advanced a theory.

"That woman was unquestionably Miss Dow, who knew Reid and who eloped that night with Morgan Mason."

The Thinking Machine looked at him a moment without speaking, then led the way into the private room where the lady had been waiting. Hatch followed. They remained there five or ten minutes, then The Thinking Machine came out and started toward the front door, only eight or ten feet from this room. The road was twenty feet away.

"Let's go," he said, finally.

"Where?" asked Hatch.

"Don't you see?" asked The Thinking Machine, irrelevantly, "that it would have been perfectly possible for Miss Melrose herself to have left the automobile and gone inside the inn for a few minutes?"

Following previously received directions The Thinking Machine now set out to find the man who had charge of the gasoline tank. They went away together and remained half an hour.

On the scientist's return to where Hatch had been waiting impatiently they climbed into the car which had brought them to the inn.

"Two miles down this road, then the first road to your right until I tell you to stop," was the order to the chauffeur.

"Where are you going?" asked Hatch, curiously.

"Don't know yet," was the enigmatic reply.

The car ran on through the night, with great, unblinking lights staring straight out ahead on a road as smooth as asphalt. The turn was made, then more slowly the car proceeded along the cross road. At the second house, dimly discernible through the night, The Thinking Machine gave the signal to stop.

Hatch leaped out, and The Thinking Machine followed. Together they approached the house, a small cottage some distance back from the road. As they went up the path they came upon another automobile, but it had no lights and the engine was still.

Even in the darkness they could see that one of the forward wheels was gone, and the front of the car was demolished.

"That fellow had a bad accident," Hatch remarked.

An old woman and a boy appeared at the door in answer to their rap.

"I am looking for a gentleman who was injured last night in an automobile accident," said The Thinking Machine. "Is he still here?"

"Yes. Come in."

They stepped inside as a man's voice called from another room:

"Who is it?"

"Two gentlemen to see the man who was hurt," the woman called.

"Do you know his name?" asked The Thinking Machine.