Under the influence of that singular feeling of some one being in the room with him, Carroll Garland opened his eyes suddenly from sound sleep. The intuition was correct; there was some one in the room with him — a man whose back was turned. At that particular moment he was examining the clothing Garland had discarded on retiring. Garland raised himself on one elbow, and the bed creaked a little.

“Don’t disturb yourself,” said the man, without turning, “I’ll be through in a minute.”

“Through what?” demanded Garland. “My pockets?”

The stranger straightened up and turned toward him. He was a tall, lithe, clean-cut young man, with crisp, curly hair, and a quizzical expression about his eyes and lips. He was in evening dress, and Garland could only admire the manner in which it fitted him. He wore an opera hat, and a light weight Inverness coat.

“I didn’t mean to wake you, really,” the stranger apologized pleasantly. “I’m sure I didn’t make any noise.”

“No, I dare say you didn’t,” replied Garland. “What do you want?”

The stranger picked up an overcoat, which lay across a chair, and deftly, with a penknife, slit the lining on each side. He did something then which Garland couldn’t see, after which he carefully folded the coat again, and laid it across the chair. “I have taken what you won at bridge at your club this evening,” he remarked. “It will save me the trouble of cashing a check.”

Garland gazed at this imperturbable, audacious person with a sort of admiration. “I trust you found the amount correct?” he said sarcastically.

“Yes, thirteen hundred and forty-seven dollars. That will do very nicely, thank you. I am leaving two hundred and some odd dollars of your own.”

“Oh, take it all,” said Garland magnanimously, “because I am going to make you return it, anyway.”

The stranger laughed pleasantly. “I am going now,” he said; “but before I go I should like to tell you that you play really an excellent game of bridge, except, perhaps, you are a little reckless on no trumps.”

“Thank you,” said Garland, and started to get out of bed.

“Now, don’t get up!” advised the stranger, still pleasantly. “I have something here in my pocket which I should dislike very much to have to use. But I will use it if necessary.”

Garland kept right on getting out of bed. “You are not such a fool as to shoot,” he said quietly. “You couldn’t get out of this hotel to save your life if you did. It is only halfpast eleven o’clock, there are people passing in the halls, and always at this time there are a great many people in the lobby. You would have to go that way. So now I’ll trouble you for the money.”

The stranger drew a glistening, shining object from his pocket, examined it casually, then went over and stood beside the call button. There was a glitter of determination in his eyes, and the smile had gone from his lips. “I certainly have no intention of returning the money — now,” he said.

“It would be best for both of us, of course, not to attract anyone’s attention.”

Garland was coming straight toward him.

“Now, don’t do anything foolish,” the stranger warned, not unkindly. “You can’t reach the call button unless you go over me; you won’t shout, because if you do I shall have to use this revolver, and take my chances below. You don’t happen to need this money, and I do. It was simply a pick-up for you at the club. If you give an alarm when I go out, it will be disagreeable for me.”

Garland stared at him in frank amazement for a moment. The stranger steadily returned the gaze.

“I’ll just take one whirl out of you anyhow,” declared Garland grimly. “I don’t happen to have a gun; but —”

And Garland sent in a vicious right swing, which would have been highly effective had the stranger’s head remained stationary. Instead, it ducked suddenly, and a left hand landed jarringly on one of Garland’s eyes. Instantly he forgot all about the burglarious intentions of his visitor; it was man to man, and Garland happened to be dexterous in the science of pugilism — Mike Donovan had taught him.

After four blows had been exchanged, Garland became suddenly convinced that the stranger’s teacher in the gentle art of bruising was more gifted even than Mike, because, in all the freedom of his pajamas, Garland got in only one blow for two, on a man who was hampered by overcoat and evening dress. A stinging jab to Garland’s mouth made him clinch, and in trying to reach the stranger’s throat, he forgot all the ethics of the game.

At this close range, the stranger delivered one short arm punch, and as Garland reeled and the world grew dark about him, he recalled the blow as being identical with one which was made famous in Carson City, at the time a world’s championship changed hands. Dazzling lights danced before his eyes for a moment, and then all was dark.

The stranger stood looking down at him, planted his opera hat more firmly on his head, drew on his gloves, opened the door, and went out. He sauntered through the lobby carelessly, paused to light a cigar, and disappeared through the revolving doors. At the curb outside, an automobile was waiting. In it sat a veiled woman, and a very much begoggled chauffeur.

“Well?” the woman asked quickly.

The stranger shook his head, climbed in beside her, and the car rushed away.

When Garland recovered consciousness, he had the impression of having experienced a remarkably vivid nightmare. But one look into the mirror at the bulbous black eye, and the absence of thirteen hundred and forty-seven dollars from his pockets, convinced him of the reality of it all. Incidentally he examined the two knife cuts in the overcoat lining, and shook his head in bewilderment.

“What the deuce did he cut those for?” he asked himself.

On the following morning Garland returned the overcoat to its owner, Hal Dickson. There is a freemasonry among roommates at college by which one acknowledges that whatever he owns belongs equally to the other. Garland had exercised certain rights which had accrued to him by reason of this comradeship upon his arrival in the city the day before. He wore then a light weight tan coat, entirely too thin for the extreme cold which set in immediately upon his arrival; so he borrowed a heavier coat, a thick frieze affair, from his old chum, and left his own light coat with him.

“I want to tell you something about this, Hal,” he said, and recited in detail the events of the night before. “Now look here where my friend cut your coat,” he said in conclusion.

Together they examined the long slits, after which they stared at each other in blank wonderment.

“Send it down to your tailor and have it relined,” remarked Garland. “Tell him to send the bill to me.”

Dickson continued to stare at the coat lining. “What did he want to cut it for?” he asked.

Garland shook his head. “Give me my own coat,” he said; “I’ve got to go back home at two-thirty, and can manage with this light coat until I get there, and may not have a chance to come here again.”

Garland was just about to put on his own coat, when he stopped in fresh amazement. “Well! Look at that!” he exclaimed.

Dickson looked. The lining of the coat was slit wide open on each side, as if with a sharp knife.

Ten minutes later the young men were on their way to police headquarters. Detective Mallory received them. The coats were laid under his official eyes, and he scrutinized them carefully.

Mallory listened, with his feet on his desk, and his cigar clinched in his teeth. “What did the thief look like?” he asked at the end.

“He had every appearance of a gentleman.”

“Just like me and you, eh?”

“Well, a little more like me,” replied Garland innocently.

“I shall put my men on it at once,” said the detective.

Garland caught the two-thirty train for a run of an hour and a half to a small city.

At fifteen minutes before five o’clock Detective Mallory was called to the long distance telephone.

“That Mr. Mallory?” came an excited voice. “Well, this is Carroll Garland. Yes, I am at home. Just as soon as I got here I went straight to my room to get a heavier overcoat. I was putting it on, when I found that the lining had been ripped open just like those other two. Now, what does that mean?”

For the first time in his life a question had been asked to which Mallory would confess that he didn’t know the answer. He scratched his head thoughtfully, then stopped doing that to tug violently at his bristly moustache. Finally he hung up the receiver with a bang, and went out personally to look into an affair which had not attracted more than passing interest at the time it was reported.

“I can readily understand,” Hutchinson Hatch was saying, “why the burglar took the money; but why did he slit the lining of the overcoat?”

The Thinking Machine didn’t say.

“Then why did he go to Dickson’s room, and slit the lining of an overcoat which Garland left there?”

Still The Thinking Machine was silent.

“And finally why did he go to Garland’s home, in another city forty miles away, and slit the lining of an overcoat there?”

Professor Augustus S. F. X. Van Dusen receded still farther into the depths of a huge chair, and sat for a long time with his squint eyes turned upward, and finger tips pressed together. At last he broke the silence. “You have given me every known fact?”

“Everything,” the reporter answered.

“There is really no problem in it at all,” The Thinking Machine declared, “unless one of the units remains undiscovered. If all are known, the solution is obvious. When the money is returned to Garland, it will definitely prove the only possible hypothesis that may be advanced.”

“When the money is returned?” gasped the reporter.

“That is what I said!” snapped the scientist crustily. “If Garland does not care to lose that thirteen hundred and forty-seven dollars, it would not be wise to press the investigation just now. If you will keep in communication with him, and inform me immediately when he receives the money, I shall undertake to close up the affair. Until then it is really not worth attention.”

Nearly a week elapsed before there was another development in the mystery — the return of thirteen hundred and forty-seven dollars, by express from Denver. Accompanying the money was an unsigned note of thanks for the use of it, and a line or two which might have been construed into an apology for the stranger’s conduct in Garland’s room.

The police were astounded; this was against all the rules of the game. Garland was a little more than astounded, and at the same time delighted at the generosity of the thief. It was not possible to develop any fact as to the identity of the intruder from the express records. Obviously the sender had used a fictitious name in Denver. When Hatch explained this point to The Thinking Machine, it was dismissed with a wave of one slender hand.

“It is really of no cons............