IT was absolutely impossible. Twenty-five chess masters from the world at large, forgathered in Boston for the annual championships, unanimously declared it impossible, and unanimity on any given point is an unusual mental condition for chess masters. Not one would concede for an instant that it was within the range of human achievement. Some grew red in the face as they argued it, others smiled loftily and were silent; still others dismissed the matter in a word as wholly absurd.

A casual remark by the distinguished scientist and logician, Professor Augustus S. F. X. Van Dusen, provoked the discussion. He had in the past aroused bitter disputes by some chance remark; in fact, had been once a sort of controversial center of the sciences. It had been due to his modest announcement of a startling and unorthodox hypothesis that he had been invited to vacate the chair of philosophy in a great university, later that university had felt honored when he accepted its degree of LL. D.

For a score of years educational and scientific institutions of the world had amused themselves by crowding degrees upon him. He had initials that stood for things he couldn’t pronounce; degrees from England, Russia, Germany, Italy, Sweden, and Spain. These were expressed recognition of the fact that his was the foremost brain in the sciences. The imprint of his crabbed personality lay heavily on half a dozen of its branches. Finally there came a time when argument was respectfully silent in the face of one of his conclusions.

The remark which had arrayed the chess masters of the world into so formidable and unanimous a dissent was made by Professor Van Dusen in the presence of three other men of standing. One of these, Dr. Charles Elbert, happened to be a chess enthusiast.

“Chess is a shameless perversion of the functions of the brain,” was Professor Van Dusen’s declaration in his perpetually irritated voice. “It is a sheer waste of effort, greater because it is possibly the most difficult of all fixed abstract problems. Of course logic will solve it. Logic will solve any problem; not most of them, but any problem. A thorough understanding of its rules would enable anyone to defeat your greatest chess players. It would be inevitable, just as inevitable as that two and two make four; not sometimes, but always. I don’t know chess, because I never do useless things, but I could take a few hours of competent instruction and defeat a man who has devoted his life to it. His mind is cramped; bound down to the logic of chess. Mine is not; mine employs logic in its widest scope.”

Dr. Elbert shook his head vigorously. “It is impossible.” he asserted.

“Nothing is impossible!” snapped the scientist. “The human mind can do anything. It is all we have to lift us above the brute creation. For Heaven’s sake, leave us that!”

The aggressive tone, the uncompromising egotism, brought a flush to Dr. Elbert’s face. Professor Van Dusen affected many persons that way, particularly those fellow-savants who, themselves men of distinction, had ideas of their own. “Do you know the purposes of chess? Its countless combinations?” asked Dr. Elbert.

“No,” was the crabbed reply; “I know nothing whatever of the game beyond the general purpose, which, I understand, is to move certain pieces in certain directions to stop an opponent from moving his king. Is that correct?”

“Yes,” said Dr. Elbert slowly; “but I never heard it stated just that way before.”

“Then, if that is correct, I maintain that the true logician can defeat the chess expert by the mechanical rules of logic. I’ll take a few hours some time, acquaint myself with the moves of the pieces, and defeat you to convince you.” Professor Van Dusen glared savagely into the eyes of Dr. Elbert.

“Not me!” said Dr. Elbert. “You say anyone; you for instance might defeat the greatest chess player. Would you be willing to meet the greatest chess player after you ‘acquaint’ yourself with the game?”

“Certainly,” said the scientist. “I have frequently found it necessary to make a fool of myself to convince people. I’ll do it again.”

This, then, was the acrimonious beginning of the discussion which aroused chess masters and brought open dissent from eminent men who had not dared for years to dispute any assertion by the distinguished Professor Van Dusen. It was arranged that at the conclusion of the championships Professor Van Dusen should meet the winner. This happened to be Tschaikowsky the Russian who had been chess champion for half a dozen years.

After this expected result of the tournament, Hillsbury, a noted American master, spent a morning with Professor Van Dusen in the latter’s modest apartments on Beacon Hill. He left there with a sadly puzzled face. That afternoon Professor Van Dusen met the Russian champion. The newspapers had said a great deal about the affair, and hundreds were present to witness the game.

There was a little murmur of astonishment when Professor Van Dusen appeared. He was slight to the point of childishness, and his thin shoulders seemed to droop beneath the weight of his enormous head. He wore a number eight hat. His brow rose straight and dome-like, and a heavy shock of long yellow hair gave him almost a grotesque appearance. The eyes were narrow slits of blue, squinting eternally through thick glasses; the face was small, clean shaven, and white with the pallor of the student. His lips made a perfectly straight line. His hands were remarkable for their whiteness, their flexibility, and for the length of the slender fingers. Physical development had never entered into the schedule of his fifty years of life.

The Russian smiled as he sat down at the chess table. He felt that he was humoring a crank. The other masters were grouped near by, curiously expectant. Professor Van Dusen began the game, opening with a queen’s gambit. At his fifth move, made without the slightest hesitation, the smile left the Russian’s face. At the tenth the master's grew tensely eager. The Russian champion was playing for honor now.

Professor Van Dusen’s fourteenth move was king’s castle to queen’s four. “Check,” he announced.

After a long study of the board the Russian protected his king with a knight. Professor Van Dusen noted the play, then leaned back in his chair with finger tips pressed together. His eyes left the board and dreamily studied the ceiling. For at least fifteen minutes there was no sound, then:

“Mate in fifteen moves!” he said quietly.

There was a quick gasp of astonishment. It took the practised eyes of the masters several minutes to verify the announcement. But the Russian champion saw and leaned back in his chair, a little white and dazed. He was not astonished; he was helplessly floundering in a maze of incomprehensible things. Suddenly he arose and grasped the slender hand of his conqueror.

“You have never played chess before?” he asked.


Mon Dieu! You are not a man; you are a brain—a machine—a thinking machine.”

“It’s a child’s game,” said the scientist abruptly. There was no note of exultation in his voice; it was still the irritable, impersonal tone which was habitual.

This, then, was Professor Augustus S. F. X. Van Dusen, Ph. D., LL. D., F. R. S., M. D., etc., etc., etc. This is how he came to be known to the world at large as The Thinking Machine. The Russian’s phrase had been applied to the scientist as a title by a newspaper reporter, Hutchinson Hatch. It had stuck.


The First Problem


THAT strange, seemingly inexplicable chain of circumstances which had to do with the mysterious disappearance of a famous actress, Irene Wallack, from her dressing room in a Springfield theater in the course of a performance, while the echo of tumultuous appreciation still rang in her ears, was perhaps the first problem which was not purely scientific that The Thinking Machine was ever asked to solve. The scientist’s aid was enlisted in this case by Hutchinson Hatch, reporter.

“But I am a scientist, a logician,” The Thinking Machine had protested. “I know nothing whatever of crime.”

“No one knows that a crime has been committed,” the reporter hastened to say.

“There is something far beyond the ordinary in this affair. A woman has disappeared, evaporated into thin air in the hearing, almost in sight, of her friends. The police can make nothing of it. It is a problem for a greater mind than theirs.”

Professor Van Dusen waved the newspaper man to a seat and himself sank back into a great cushioned chair in which his diminutive figure seemed even more child-like than it really was.

“Tell me the story,” he said petulantly, “All of it.”

The enormous yellow head rested against the chair back, the blue eyes squinted steadily upward, the slender fingers were pressed tip to tip. The Thinking Machine was in a receptive mood. Hatch was triumphant; he had had only a vague hope that he could interest this man in an affair which was as bizarre as it was incomprehensible.

“Miss Wallack is thirty years old and beautiful,” the reporter began. “As an actress she has won high recognition not only in this country but in England. You may have read something of her in the daily papers, and if——”

“I never read the papers,” the other interrupted curtly. “Go on.”

“She is unmarried, and as far as anyone knows, had no immediate intention of changing her condition,” Hatch resumed, staring curiously at the thin face of the scientist. “I presume she had admirers—most beautiful women of the stage have—but she is one whose life has been perfectly clean, whose record is an open book. I tell you this because it might have a bearing on your conclusion as to a possible reason for her disappearance.

“Now the actual circumstances of that disappearance. Miss Wallack has been playing in Shakespearean repertoire. Last week she was in Springfield. On Saturday night, which concluded her engagement there, she appeared as Rosalind in ‘As You Like It.’ The house was crowded. She played the first two acts amid great enthusiasm, and this despite the fact that she was suffering intensely from headache to which she was subject at times. After the second act she returned to her dressing room and just before the curtain went up for the third the stage manager called her. She replied that she would be out immediately. There seems no possible shadow of doubt that it was her voice.

“Rosalind does not appear in the third act until the curtain has been up for six minutes. When Miss Wallack’s cue came she did not answer it. The stage manager rushed to her door and again called her. There was no answer. Then, fearing that she might have fainted, he went in. She was not there. A hurried search was made without result, and the stage manager finally was compelled to announce to the audience that the sudden illness of the star would make it impossible to finish the performance.

“The curtain was lowered and the search resumed. Every nook and corner back of the footlights was gone over. The stage doorkeeper, William Meegan, had seen no one go out. He and a policeman had been standing at the stage door talking for at least twenty minutes. It is therefore conclusive that Miss Wallack did not leave by that exit. The only other way it was possible to leave the stage was over the footlights. Of course she didn’t go that way. Yet no trace of her has been found. Where is she?”

“The windows?” asked The Thinking Machine.

“The stage is below the street level,” explained Hatch. “The window of her dressing room, Room A, is small and barred with iron. It opens into an air shaft that goes straight up for ten feet, and that is covered with an iron grating fixed in the granite. The other windows on the stage are not only inaccessible but are also barred with iron. She could not have approached either of these windows without being seen by other members of the company or the stage hands.”

“Under the stage?” suggested the scientist.

“Nothing,” the reporter went on. “It is a large cemented basement which was vacant. It was searched, because there was of course a chance that Miss Wallack might have become temporarily unbalanced and wandered down there. There was even a search made of the flies—that is the galleries over the stage where the men who work the drop curtains are stationed.”

There was silence for a long time. The Thinking Machine twiddled his fingers and continued to stare upward. He had not looked at the reporter. He broke the silence after a time. “How was Miss Wallack dressed at the time of her disappearance?”

“In doublet and hose—that is, tights,” the newspaper man responded. “She wears that costume from the second act until practically the end of the play.”

“Was all her street clothing in her room?”

“Yes, everything, spread across an unopened trunk of costumes. It was all as if she had left the room to answer her cue—all in order even to an open box of chocolate-cream candy on her table.”

“No sign of a struggle, nor any noise heard?”


“Nor trace of blood?”


“Her maid? Did she have one?”

“Oh, yes. I neglected to tell you that the maid, Gertrude Manning, had gone home immediately after the first act. She grew suddenly ill and was excused.”

The Thinking Machine turned his squint eyes on the reporter for the first time.

“Ill?” he repeated. “What was the matter?”

“That I can’t say,” replied the reporter.

“Where is she now?”

“I don’t know. Everyone forgot all about her in the excitement about Miss Wallack.”

“What kind of candy was it?”

“I’m afraid I don’t know that either.”

“Where was it bought?'”

The reporter shrugged his shoulders; that was something else he didn’t know.

The Thinking Machine shot out the questions aggressively, staring meanwhile steadily at Hatch, who squirmed uncomfortably. “Where is the candy now?” demanded the scientist.

Again Hatch shrugged his shoulders.

“How much did Miss Wallack weigh?”

The reporter was willing to guess at this. He had seen her half a dozen times.

“Between a hundred and thirty and a hundred and forty,” he ventured.

“Does there happen to be a hypnotist connected with the company?”

“I don’t know,” Hatch replied.

The Thinking Machine waved his slender hands impatiently; he was annoyed. “It is perfectly absurd, Mr. Hatch,” he expostulated, “to come to me with only a few facts and ask advice. If you had all the facts I might be able to do something; but this——”

The newspaper man was nettled. In his own profession he was accredited a man of discernment and acumen. He resented the tone, the manner, even the seemingly trivial questions, which the other asked. “I don’t see,” he began, “that the candy even if it had been poisoned as I imagine you think possible, or a hypnotist could have had anything to do with Miss Wallack’s disappearance. Certainly neither poison nor hypnotism would have made her invisible.”

“Of course you don’t see!” blazed The Thinking Machine. “If you did, you wouldn’t have come to me. When did this thing happen?”

“Saturday night, as I said,” the reporter informed him a little more humbly. “It closed the engagement in Springfield. Miss Wallack was to have appeared here in Boston to-night.”

“When did she disappear— by the clock, I mean?”

“The stage manager’s time slip shows that the curtain for the third act went up at nine-forty-one—he spoke to her, say, one minute before, or at nine-forty. The action of the play before she appears in the third act takes six minutes; therefore——”

“In precisely seven minutes a woman, weighing more than 130 pounds, certainly not dressed for the street, disappeared completely from her dressing room. It is now five-eighteen Monday afternoon. I think we may solve this crime within a few hours.”

“Crime?” Hatch repeated eagerly. “Do you imagine there is a crime then?”

Professor Van Dusen didn’t heed the question. Instead he rose and paced back and forth across the reception room half a dozen times, his hands behind his back and his eyes cast down. At last he stopped and faced the reporter, who had also risen.

“Miss Wallack’s company, I presume, with the baggage, is now in Boston,” he said. “See every male member of the company, talk to them and particularly study their eyes. Don’t overlook anyone, however humble. Also find out what became of the box of chocolate candy, and if possible how many pieces are out of it. Then report here to me. Miss Wallack’s safety may depend upon your speed and accuracy.”

Hatch was frankly startled. “How——” he began.

“Don’t stop to talk—hurry!” commanded The Thinking Machine. “I will have a cab waiting when you come back. We must get to Springfield.”

The newspaper man rushed away to obey orders. He didn’t understand them at all. Studying men’s eyes was not in his line; but he obeyed nevertheless. An hour and a half later he returned, to be thrust unceremoniously into a waiting cab by The Thinking Machine. The cab rattled away toward South Station, where the two men caught a train, just about to move out for Springfield. Once settled in their seats, the scientist turned to Hatch, who was nearly suffocating with suppressed information.

“Well?” he asked.

“I found out several things,” the reporter burst out. “First, Miss Wallack’s leading man, Langdon Mason, who has been in love with her for three years, bought the candy at Schuyler’s in Springfield early Saturday evening before he went to the theater. He told me so himself rather reluctantly; but I—I made him say it.”

“Ah!” exclaimed The Thinking Machine. It was a most unequivocal ejaculation. “How many pieces of candy are out of the box?”

“Only three,” explained Hatch. “Miss Wallack’s things were packed into the open trunk in her dressing room, the candy with them. I induced the manager——”

“Yes, yes, yes!” interrupted The Thinking Machine impatiently. “What sort of eyes has Mason? What colour?”

“Blue, frank in expression, nothing unusual at all,” said the reporter.

“And the others?”

“I didn’t quite know what you meant by studying their eyes, so I got a set of photographs. I thought perhaps they might help.”

“Excellent, Excellent!” commented The Thinking Machine. He shuffled the pictures through his fingers, stopping now and then to study one, and to read the name printed below. “Is that the leading man?” he asked at last, and handed one to Hatch.


Professor Van Dusen did not speak again. The train pulled into Springfield at nine-twenty. Hatch followed the scientist without a word into a cab.

“Schuyler’s candy store,” quickly commanded The Thinking Machine. “Hurry.”

The cab rushed off through the night. Ten minutes later it stopped before a brilliantly lighted candy store. The Thinking Machine led the way inside and approached the girl behind the chocolate counter.

“Will you please tell me if you remember this man’s face?” he asked as he produced Mason’s photograph.

“Oh, yes, I remember him,” the girl replied. “He’s an actor.”

“Did he buy a small box of chocolates of you Saturday evening early?” was the next question.

“Yes. I recall it because he seemed to be in a hurry; in fact, I believe he said he was anxious to get to the theater to pack.”

“And do you recall that this man ever bought chocolates here?” asked the scientist. He produced another photograph and handed it to the girl. She studied it a moment while Hatch craned his neck, vainly, to see.

“I don’t recall that he ever did,” the girl answered finally.

The Thinking Machine turned away abruptly and disappeared into a public telephone booth. He remained there for five minutes, then rushed out to the cab again, with Hatch following closely.

“City Hospital!” he commanded.

Again the cab dashed away. Hatch was dumb; there seemed to be nothing to say. The Thinking Machine was plainly pursuing some definite line of inquiry, yet the reporter didn’t know what. The case was getting kaleidoscopic. This impression was strengthened when he found himself standing beside The Thinking Machine in City Hospital conversing with the house surgeon, Dr. Carlton.

“Is there a Miss Gertrude Manning here?” was the scientist’s first question.

“Yes,” replied the surgeon. “She was brought here Saturday night, suffering from——”

“Strychnine poisoning, yes, I know,” interrupted the other. “Picked up in the street, probably. I am a physician. If she is well enough I should like to ask her a couple of questions.”

Dr. Carlton agreed, and Professor Van Dusen, still followed faithfully by Hatch, was ushered into the ward where Miss Wallack’s maid lay, pallid and weak. The Thinking Machine picked up her hand and his slender finger rested for a minute on her pulse. He nodded and seemed satisfied.

“Miss Manning, can you understand me?” he asked.

The girl nodded weakly.

“How many pieces of the candy did you eat?”

“Two,” she replied. She stared into the face above her with dull eyes.

“Did Miss Wallack eat any of it up to the time you left the theatre?”


If the Thinking Machine had been in a hurry previously, he was racing now. Hatch trailed on dutifully behind, down the stairs, and into the cab, whence Professor Van Dusen shouted a word of thanks to Dr. Carlton. This time their destination was the stage door of the theatre from which Miss Wallack had disappeared.

The reporter was muddled. He didn’t know anything very clearly except that three pieces of candy were missing from the box. Of these the maid had eaten only two. She had been poisoned. Therefore, it seemed reasonable to suppose that if Miss Wallack had eaten the third piece she also would be poisoned. But poison would not make her invisible. At this point the reporter shook his head hopelessly.

William Meegan, the stage doorkeeper, was easily found.

“Can you inform me, please,” began The Thinking Machine, “if Mr. Mason left a box of candy with you last Saturday night for Miss Wallack?”

“Yes,” Meegan replied good-naturedly. He was amused at the little man. “Miss Wallack hadn’t arrived. Mason brought a box of candy for her nearly every night and usually left it here. I put the one Saturday night on the shelf here.”

“Did Mr. Mason come to the theatre before or after the others on Saturday night?”

“Before,” replied Meegan. “He was unusually early, I suppose, to pack.”

“And the other members of the company coming in stop here, I imagine, to get their mail?” and the scientist squinted up at the mail box above the shelf.

“Sure, always.”

The Thinking Machine drew a long breath. Up to this time there had been little perplexed wrinkles in his brow. Now they disappeared.

“Now, please,” he went on, “was any package or box of any kind taken from the stage on Saturday night between nine and eleven o’clock?”

“No,” said Meegan positively. “Nothing at all until the company’s baggage was removed at midnight.”

“Miss Wallack had two trunks in her dressing room?”

“Yes. Two whacking big ones too.”

“How do you know?”

“Because I helped put ’em in and helped take ’em out,” replied Meegan sharply. “What's it to you?”

Suddenly The Thinking Machine turned and ran out to the cab, with Hatch, his shadow, close behind.

“Drive, drive as fast as you know how to the nearest long-distance telephone!” the scientist instructed the cabby. “A woman’s life is at stake.”

Half an hour later Professor Van Dusen and Hutchinson Hatch were on a train rushing back to Boston. The Thinking Machine had been in the telephone booth for fifteen minutes. When he came out Hatch had asked several questions, to which the scientist vouchsafed no answer. They were perhaps thirty minutes out of Springfield before the scientist showed any disposition to talk. Then he began, without preliminary, much as he was resuming a former conversation.

“Of course if Miss Wallack didn’t leave the stage of the theater she was there,” he said. “We will admit that she did not become invisible. The problem therefore was to find her on the stage. The fact that no violence was used against her was conclusively proved by half a dozen instances. No one heard her scream; there was no struggle, no trace of blood. Ergo, we assume in the beginning that she must have consented to the first steps which led to her disappearance. Remember her attire was wholly unsuited to the street.

“Now let us shape a hypothesis which will fit all the circumstances. Miss Wallack had a severe headache. Hypnotic influence will cure headaches. Was there a hypnotist to whom Miss Wallack would have submitted herself? Assume there was. Then would that hypnotist take advantage of his control to place her in a cataleptic condition? Assume a motive and he would. Then, how would he dispose of her?

“From this point questions radiate in all directions. We will confine ourselves to the probable, granting for the moment that this hypothesis, the only one which fits all the circumstances, is correct. Obviously, a hypnotist would not have attempted to get her out of the dressing room. What remains? One of the two trunks in her room.

Hatch gasped. “You mean you think it possible that she was hypnotized and placed in that second trunk, the one that was strapped and locked?” he asked.

“It’s the only thing that could have happened,” said The Thinking Machine emphatically; “therefore that was just what did happen.”

“Why, it’s horrible!” exclaimed Hatch. “A live woman in a trunk for forty-eight hours? Even if she was alive then, she must be dead now.”

The reporter shuddered a little and gazed curiously at the inscrutable face of his companion. He saw no pity, no horror, there; there was merely the reflection of the workings of a brain.

“It does not necessarily follow that she is dead,” explained The Thinking Machine. “If she ate that third piece of candy before she was hypnotized she is probably dead. If it was placed in her mouth after she was in a cataleptic condition the chances are that she is not dead. The candy would not melt and her system could not absorb the poison.”

“But she would be suffocated—her bones would be broken by the rough handling of the trunk—there are a hundred possibilities,” the reporter suggested.

“A person in a cataleptic condition is singularly impervious to injury,” replied the scientist. “There is of course a chance of suffocation, but a great deal of air may enter a trunk.”

“And the candy?” Hatch asked.

“Yes, the candy. We know that two pieces of candy nearly killed the maid. Yet Mr. Mason admitted having bought it. This admission indicated that this poisoned candy is not the candy he bought. Is Mr. Mason a hypnotist? No. He hasn’t the eyes. His picture tells me that. We know that Mr. Mason did buy candy for Miss Wallack on several occasions. We know that sometimes he left it with the stage doorkeeper. We know that members of the company stopped there for mail. We instantly see that it is possible for one to take away that box and substitute poisoned candy. All the boxes are alike.

“Madness and the cunning of madness lie back of all this. It was a deliberate attempt to murder Miss Wallack, long pondered and due, perhaps, to unrequited or hopeless infatuation. It began with the poisoned candy, and that failing, went to a point immediately following the moment when the stage manager last spoke to the actress. The hypnotist was probably in her room then. You must remember that it would have been possible for him to ease the headache, and at the same time leave Miss Wallack free to play. She might have known this from previous experience.”

“Is Miss Wallack still in the trunk?” asked Hatch after a silence.

“No,” replied the Thinking Machine. “She is out now, dead or alive—I am inclined to believe alive.”

“And the man?”

“I will turn him over to the police in half an hour after we reach Boston.”

From South Station the scientist and Hatch were driven immediately to Police Headquarters. Detective Mallory, whom Hatch knew well, received them.

“We got your ’phone from Springfield——” he began.

“Was she dead?” interrupted the scientist.

“No,” Mallory replied. “She was unconscious when we took her out of the trunk, but no bones are broken. She is badly bruised. The doctor says she’s hypnotized.”

“Was the piece of candy taken from her mouth?”

“Sure, a chocolate cream. It hadn’t melted.”

“I’ll come back here in a few minutes and awake her,” said The Thinking Machine. “Come with us now, and get the man.”

Wonderingly the detective entered the cab and the three were driven to a big hotel a dozen blocks away. Before they entered the lobby The Thinking Machine handed a photograph to Mallory, who studied it under an electric light.

“That man is upstairs with several others,” explained the scientist. “Pick him out and get behind him when we enter the room. He may attempt to shoot. Don’t touch him until I say so.”

In a large room on the fifth floor Manager Stanfeld of the Irene Wallack Company had assembled the men of her support. This was done at the ’phoned request of The Thinking Machine. There were no preliminaries when Professor Van Dusen entered. He squinted comprehensively about him, then went straight to Langdon Mason.

“Were you on the stage in the third act of your play before Miss Wallack was to appear—I mean the play last Saturday night?” he asked.

“I was,” Mason replied, “for at least three minutes.”

“Mr. Stanfeld, is that correct?”

“Yes,” replied the manager.

There was a long tense silence broken only by the heavy footsteps of Mallory as he walked toward a distant corner of the room. A faint flush crept into Mason’s face as he realized that the questions were almost an accusation. He started to speak, but the steady, impassive voice of The Thinking Machine stopped him.

“Mr. Mallory, take your prisoner,” it said.

Instantly there was a fierce, frantic struggle, and those present turned to see the detective with his great arms locked about Stanley Wightman, the melancholy Jaques of “As You Like It.” The actor’s face was distorted, madness blazed in the eyes, and he snarled like a beast at bay. By a sudden movement Mallory threw Wightman and manacled him, then looked up to find The Thinking Machine peering over his shoulder at the prostrate man.

“Yes, he’s a hypnotist,” the scientist remarked in self-satisfied conclusion. “It always tells in the pupils of the eyes.”

This, then, was the beginning and end of the first problem. Miss Wallack was aroused, and told a story almost identical with that of The Thinking Machine. Stanley Wightman, whose brooding over a hopeless love for her made a maniac of him, raves and shrieks the lines of Jaques in the seclusion of a padded cell.