"That's all right-that's all right," murmured the young man, and overcome by the exertion of speech his head dropped back and in a moment he was sound asleep.
Without apparent compunction The Thinking Machine searched his pockets. After a moment he found what seemed to be a rough rock crystal. He squinted at it closely as he turned and twisted it back and forth in his hand, then passed it to Hatch for inspection.
"That's worth forty thousand dollars," he remarked casually.
"Is this the--"
"It's the Colgate diamond," interrupted The Thinking Machine. "I surmised that he would have it somewhere about him, because he would have no place to hide it. And now for the second man-the brains of the theft. First I shall telephone for Colgate. Look at him when he enters; for I think you will be greatly surprised. And above all, remember to be careful."
Looking deeply into the quiet, squint eyes of the scientist, Hatch read a warning. He understood and nodded. Travers, stupefied, was removed to an adjoining room.
A few minutes later there was a rattle of carriage wheels, the door bell rang, and Colgate entered. Hatch glanced at him, then turned quickly to look out of a window.
"You have the diamond?" burst out Colgate suddenly.
"I said I would have it when you came," retorted The Thinking Machine. "Now for these post cards," and the scientist produced the three cards that had been handed to him at first. "Perhaps you would be interested to know what was really on them?"
"I haven't the slightest curiosity," said Colgate impatiently. "All I want is the diamond. If you will give me that, I think perhaps that will terminate this affair, and there will be no necessity of taking up more of your time."
"Of course you have no desire to prosecute Travers?" asked The Thinking Machine. There was a velvety note in the crabbed voice. Hatch glanced at him.
"I don't think I care to prosecute him," said Colgate steadily.
"I thought perhaps you would not," rejoined The Thinking Machine enigmatically. "But as to these post cards. They constitute what is known as the book cipher. For your information I may state that it is always possible to know a book cipher by the fact that a small number, rarely above twelve or fourteen, always precedes the X; the X merely divides the words. For instance, on the first card we have I-28-38-4; in other words, volume one, page 28, line 38, and the fourth word of that line. Unless one knows or can learn the name of the book which is the basis of the cipher, it is perhaps the most difficult of all. Any ordinary cipher may be solved precisely as Poe solved his great cipher in 'The Gold Bug.' "
"But I am not at all interested--" protested Colgate.
"So really all that was necessary for me to do was to find out what book was the basis of this particular cipher," continued The Thinking Machine to Hatch, without heeding his visitor's remark. "I knew of course it was some book in Mr. Colgate's home. The clue to what book was given, either wittingly or unwittingly, by the single I, the two I's and the three I's on the first, second, and third cards. Did these represent volumes? I found a dozen three volume books in Mr. Colgate's library, but in each instance there was no connection in the first three or four words which I found in accordance with the numbers given; that is, until I came to 'Ten Thousand a Year.' The first word I found in that was 'will'; the second, page 47, line 30, second word, was 'return'; the third was 'diamond.' So I knew that was the book I wanted. Here is the full meaning of the cipher as it appears on the three cards, as I have transcribed it."
He handed Colgate a slip of paper, on which was written:
Will return diamond for ten thousand. If you agree informed [present tense-i.e., inform] me in daily press.
"This all seems very clever and very curious indeed," commented Colgate; "but really I do not think--"
"The book of Mr. Colgate's is a first edition-there is also a first edition in the public library," the scientist went on placidly; "so Travers had no difficulty on that score. We shall admit that the cards were mailed in Philadelphia; perhaps he went there and later returned to this city. The manner in which I got possession of the diamond-by first discovering Travers through an advertisement and then keeping him at the telephone until he was inveigled here by my assistant-is possibly of no interest; it was all very easily done by a prearranged plan with the telephone exchange; so now, Mr.-Mr.--"
"Colgate," his visitor supplied, as if surprised at the hesitancy.
"I mean your real name," said the scientist quietly.
There was a sudden tense silence; Hatch had come a little closer, and was staring at the stranger with keen, inquiring eyes.
"This is not the Mr. William C. Colgate you know, Mr. Hatch?"
"No."
"Do you happen to have an idea who he is?"
"If I am not mistaken," Hatch replied calmly, "this is a gentleman I have met before on an exceedingly interesting occasion-Mr. Bradlee Cunnyngham Leighton."
At the name the erstwhile Colgate turned upon the reporter with a snarl. There was a quick movement of his right hand, and Hatch found himself blinking down the barrel of a revolver, as Leighton slowly moved backward toward the door.
The Thinking Machine moved around behind the aggressor. "Now, Mr. Leighton," he said almost pleasantly, "if you don't lower that revolver I'll blow your brains out."
For one instant Leighton hesitated, then glanced back quickly toward the scientist. That diminutive man stood calmly, with his hands in his pockets. Instantly Hatch leaped. There was a quick, sharp struggle, a few muttered curses, and then the discomfited Leighton, in his turn, was gazing down the revolver barrel.
"Won't you gentlemen sit down?" suggested The Thinking Machine.
They were all sitting down when Detective Mallory rushed up from police headquarters. Leighton was farthest from the door. The Thinking Machine sat staring at him with the revolver held in position for quick use.
"Ah, Mr. Mallory," he said, without turning his head or glancing back. "This is Mr. Bradlee Cunnyngham Leighton. You may have heard of him before?"
"Do you mean the Englishman who brought the Varron necklace to this country?" blurted out the detective.
"The same man of the carrier pigeon case," said Hatch grimly.
"I should like particularly to call your attention to Mr. Leighton," continued The Thinking Machine. "He is a man of accomplishments. We know how he distinguished himself by the simple expedient of using carrier pigeons in the Varron necklace affair. In this case, he has risen to greater heights. First-I am assuming some things-he plotted with young Travers to steal the Colgate diamond. In some manner, which is not essential here, Travers got the diamond and sought to profit by the theft alone by negotiating its return for ten thousand dollars. Travers wrote a cipher to Mr. Colgate making the proposition-it was possible he knew Mr. Colgate would understand his cipher. I shall give Leighton credit for anticipating just this possibility and intercepting the post cards. They meant nothing to him; so-please note this-he came to me as Mr. Colgate, knowing that Mr. Colgate was in Europe with his family, and sought my assistance in recovering the jewel from his fellow conspirator. The sublime audacity of all these conceptions marks Mr. Leighton as little short of a genius in his particular profession.
"Only once was Mr. Leighton embarrassed. That was when I told him I should have to visit his library. But he even rose to this necessity brilliantly. He delayed my visit for a day or so, and in some manner, possibly by forgery, secured an entrance to Mr. Colgate's home, perhaps as a cousin of the same name. There he received me. Two or three things had happened to arouse a doubt in my mind as to whether he was the real Mr. Colgate.
"First was his hesitancy in connection with my visit to the library; then while I was in the house a telegram came for Mr. William C. Colgate. A servant asked Mr. Leighton in my presence if the telegram was for him. That question would never have been asked if he had been the real William C. Colgate. Then finally I asked Mr. Hatch over the phone if William C. Colgate was red-headed. William C. Colgate is not red-headed. This gentleman is, therefore he is not William C. Colgate. I only knew this much. Mr. Hatch recognized him as Leighton. He saw him at the time you were all interested in his escape from a Scotland Yard man-Conway, who wanted him for stealing a necklace. That is all, I think."
"But the diamond and Travers?" asked the detective.
"Here is the diamond," said The Thinking Machine, and he produced it from one of his pockets. "Travers is lying on a bed in the next room in a drunken stupor."
THE THREE OVERCOATS.
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."