"Have you three-volume book of any sort that you read or refer to frequently?"
For some reason Colgate seemed a little startled. It was only momentary, however. "I suppose I have several books of three volumes," he replied.
"No particular one that your secretary would know that you read frequently?" insisted the scientist.
Again some strange impalpable expression flitted across Colgate's face. "No," he said after a moment.
The Thinking Machine arose. "It will be necessary then," he said, "for me to go over your library and see if I can't find the book to which this cipher refers."
"Book?" asked Colgate curiously. "If the cipher has no relation to the diamond, I don't see that--"
"Of course you don't see!" snapped The Thinking Machine. "Come along and let me see."
Colgate seemed a little perturbed by the suggestion. He folded his immaculate gloves over and over as he stared at the inscrutable face before him. "It would be impossible," he said at last, "to find anything in my library just now. As I said, my wife and daughters are abroad, and during their absence I have taken occasion to have my library and one or two other rooms redecorated and refinished. All my books meanwhile are packed away, helter skelter."
The Thinking Machine sat down again and stared at him inquiringly. "Then when your library is in order again you may call," he said tersely. "I can do nothing until I see the books."
"But-but--" stammered Colgate.
"Good day," said The Thinking Machine curtly.
Colgate went away. It was not till three days later that he reappeared. If one might have judged by his manner, he had achieved something in his absence; yet when he spoke it was in the same exquisitely modulated tone of the first visit.
"The work of redecorating has been completed," he told The Thinking Machine. "My library is again in order, and you may examine it at your leisure. If you care to go now, my carriage is at the door."
The Thinking Machine stared at him for a moment, then picked up his hat. At the door of the Colgate mansion Colgate and the scientist were met by a graven-faced footman, who received their hats and coats in silence. Colgate conducted his guest straight into the library. It was a magnificently appointed place, reflecting in its every detail the splendid purchasing power of money. To this sheer luxury, however, The Thinking Machine was oblivious. His undivided attention was on the book shelves.
From one end of the long room to the other he walked time after time, reading the titles of the books as he passed. There were Dickens, Balzac, Kipling, Stevenson, Thackeray, Zola-all of them. Three or four times he paused to draw out a volume and examine it. Each time he replaced it without a word and continued his search. Colgate stood by, watching him curiously.
The Thinking Machine had just paused to draw out one of the Dumas books when the stolid-faced footman appeared in the door with a telegram.
"Is this for you, sir?" he asked of Colgate.
"Yes," replied Colgate.
He drew out the yellow sheet and permitted the envelope to fall to the floor. The Thinking Machine picked it up with something like eagerness in his manner. It was directed to "William C. Colgate." The scientist looked almost astonished as he turned again to the book shelves.
It was ten minutes later that The Thinking Machine took out three volumes together. These comprised the famous old English novel, "Ten Thousand a Year," a rare and valuable first edition. The leaves of volume 1 fluttered through his fingers until he came to page 28. After a moment he said "Ah!" Then he went on to page 47. He studied that for a moment or more, after which he said "Ah!" once again.
"What is it?" inquired Colgate quickly.
The Thinking Machine turned his cold, squint eyes up into the eager face above him. "It is the key to the cipher," he said.
"What is it? Read it!" commanded Colgate. His clear, alert eyes were fastened on the, to him, meaningless page. He sought vainly there something to account for the scientist's exclamation. But he saw only words-a page of words with no apparent meaning beyond the text of the story. "What is it?" he demanded again, and there was a little glitter in his eye. "Does it say where the diamond is?"
"Considering the fact that I have seen only two words of a possible twenty or thirty, I don't know what it says," declared The Thinking Machine aggressively. "The best I can say now is that with the aid of these books I shall find the diamond."
For half an hour or more the scientist was busy running through the books in an aimless sort of way. Finally he closed the third volume with a snap and stood up.
"Travers says that he will return the gem for ten thousand dollars," he announced.
"Oh, he does, does he?" Colgate's tone was a sneer. Again in his face The Thinking Machine read some subtle quality which brought a slight wrinkle of perplexity to his brow.
"You don't have to pay it, you know," he explained tartly. "I can get it without the ten thousand dollars, of course."
"Well, get it, then!" said Colgate a little impatiently. "I want the diamond, and it is absurd to suppose that I shall pay ten thousand dollars for my own property. Come on! Let's do what is to be done immediately."
"I'll do what is to be done immediately; but I will do it without your assistance," remarked The Thinking Machine. "I shall send for you to-morrow. When you come the diamond will be in my possession. Good day."
Colgate stared after him blankly as he went out.
The Thinking Machine was talking over the telephone with Hutchinson Hatch, reporter.
"Do you know William C. Colgate by sight?" he demanded.
"Very well," Hatch replied.
"Is he red-headed?"
"No."
"Good by."
On the following morning a short advertisement appeared in all the city newspapers. It was simply:
Will give ten thousand dollars. Matter is not in hands of the police. To insure your safety, telephone 1103 Bay and arrange details.
It was only a few minutes past nine o'clock that morning when The Thinking Machine was called to the telephone. For some reason he had difficulty in understanding, possibly due to the spluttering of the receiver. Then he did understand, and sat down for some time, apparently to consider what he had heard. Later he telephoned to Hutchinson Hatch.
"It's about this theft of the Colgate diamond," he explained. "The secretary, Travers, who is wanted for the theft, is now somewhere in the North End, either drunk or drugged, and possibly disguised. I imagine his photograph has been in all the newspapers. I have been talking to him over the telephone, and he is to call me again about eleven o'clock. Go down to the North End near the corner of Hanover and Blank Streets, hire a telephone for the morning, and call me. Remain at the phone from half-past ten until I call you. You are to get Travers. When you get him bring him here. Don't notify the police."
"But will I get him?" asked the reporter.
"If you don't you are stupid," retorted The Thinking Machine.
At five minutes of eleven o'clock the scientist's telephone rang. He was sitting staring at it at the moment, but instead of answering stepped to the door and called Martha, his aged servant.
"Answer the telephone," he directed, "and tell whoever is there that I am not here. Tell them I shall return in ten minutes, and to be sure to call me again."
Martha followed the instructions and hung up the receiver. Instantly The Thinking Machine went to the telephone.
"Can you tell me, please, the number of the telephone which just called me?" he asked quickly. "No, I don't want a connection. Number 34710 North, in a cafe at Hanover and Blank Streets? Thanks."
A minute later he had Hatch on the wire again. "Travers will call me in five minutes from 34710 North, in a cafe at Hanover and Blank Streets," he said. "Get him and bring him here as quickly as you can. Good by."
So it came about that within less than an hour a cab rushed up to the door, and Hutchinson Hatch, accompanied by a young man, entered. The man was Travers. A week's scrubby beard was on his chin, his face was perfectly pallid; the fever of drink and fear glittered in his eyes. Hatch had to support him to a chair, in which he dropped back limply. The Thinking Machine scowled down into the young man's face, and was met by a fishy, imbecilic stare in return.
"Are you Mr. Travers?" inquired The Thinking Machine.