The Thinking Machine was silent on that point.

[Ill.u.s.tration]

"Well, Mr. Hatch," he said finally, "the problem comes down to this: Did a man, and perhaps a woman, who are circ.u.mstantially proven guilty of stealing the gold plate, _actually_ steal it? We have the stained cushion of the automobile in which the thieves escaped to indicate that one of them was wounded; we have Mr. Herbert with an injured right shoulder--a hurt received that night on his own statement, though he won't say how. We have, then, the second theft and the finding of the stolen property in his possession along with another lot of stolen stuff--jewels. It is apparently a settled case now without going further."

"But----" Hatch started to protest.

"But suppose we do go a little further," The Thinking Machine went on.

"I can prove definitely, conclusively, and finally by settling only two points whether or not Mr. Herbert was wounded while in the automobile.

If he was wounded while in that automobile, he was the first thief; if not, he wasn't. If he was the first thief, he was probably the second, but even if he were not the first thief, there is, of course, a possibility that he was the second."

Hatch was listening with mouth open.

"Suppose we begin now," continued The Thinking Machine, "by finding out the name of the physician who treated Mr. Herbert's wound last Thursday night. Mr. Herbert may have a reason for keeping the ident.i.ty of this physician secret, but, perhaps--wait a minute," and the scientist disappeared into the next room. He was gone for five minutes. "See if the physician who treated the wound wasn't Dr. Clarence Walpole."

The reporter blinked a little.

"Right," he said. "What next?"

"Ask him something about the nature of the wound and all the usual questions."

Hatch nodded.

"Then," resumed The Thinking Machine casually, "bring me some of Mr.

Herbert's blood."

The reporter blinked a good deal, and gulped twice.

"How much?" he inquired briskly.

"A single drop on a small piece of gla.s.s will do very nicely," replied the scientist.

CHAPTER II

The Supreme Police Intelligence of the Metropolitan District was doing some heavy thinking, which, modestly enough, bore generally on his own dazzling perspicacity. Just at the moment he couldn't recall any detector of crime whose l.u.s.tre in any way dimmed his own, or whose mere shadow, even, had a right to fall on the same earth as his; and this lapse of memory so stimulated his admiration for the subject of his thoughts that he lighted a fresh cigar and put his feet in the middle of the desk.

He sat thus when The Thinking Machine called. The Supreme Intelligence--Mr. Mallory--knew Professor Van Dusen well, and, though he received his visitor graciously, he showed no difficulty in restraining any undue outburst of enthusiasm. Instead, the same admirable self-control which prevented him from outwardly evidencing his pleasure prompted him to square back in his chair with a touch of patronising aggressiveness in his manner.

"Ah, Professor," was his noncommittal greeting.

"Good-evening, Mr. Mallory," responded the scientist in the thin, irritated voice which always set Mr. Mallory's nerves a-jangle. "I don't suppose you would tell me by what steps you were led to arrest Mr.

Herbert?"

"I would not," declared Mr. Mallory promptly.

"No, nor would you inform me of the nature of the evidence against him in addition to the jewels and plate found in his possession?"

"I would not," replied Mr. Mallory again.

"No, I thought perhaps you would not," remarked The Thinking Machine. "I understand, by the way, that one of your men took a leather cushion from the automobile in which the thieves escaped on the night of the ball?"

"Well, what of it?" demanded the detective.

"I merely wanted to inquire if it would be permissible for me to see that cushion?"

Detective Mallory glared at him suspiciously, then slowly his heavy face relaxed, and he laughed as he arose and produced the cushion.

"If you're trying to make any mystery of this cushion, you're in bad,"

he informed the scientist. "We know the owner of the automobile in which Herbert and the Girl escaped. The cushion means nothing."

The Thinking Machine examined the heavy leather carefully and paid a great deal of attention to the crusted stains which it bore. He picked at one of the brown spots with his penknife and it flaked off in his hand.

"Herbert was caught with the goods on," declared the detective, and he thumped the desk with his l.u.s.ty fist. "We've got the right man."

"Yes," admitted The Thinking Machine, "it begins to look very much as if you _did_ have the right man--for once."

Detective Mallory snorted.

"Would you mind telling me if any of the jewelry you found in Mr.

Herbert's possession has been identified?"

"Sure thing," replied the detective. "That's where I've got Herbert good. Four people who lost jewelry at the masked ball have appeared and claimed pieces of the stuff."

For an instant a slightly perplexed wrinkle appeared in the brow of The Thinking Machine, and as quickly it pa.s.sed.

"Of course, of course," he mused.

"It's the biggest haul of stolen goods the police of this city have made for many years," the detective volunteered complacently. "And, if I'm not wrong, there's more of it coming--no man knows how much more. Why, Herbert must have been operating for years, and he got away with it, of course, by the gentlemanly exterior, the polish, and all that. I consider his capture the most important that has happened since I have been connected with the police."

"Indeed?" inquired the scientist thoughtfully. He was still gazing at the cushion.

"And the most important development of all is to come," Detective Mallory rattled on. "That will be the real sensation, and make the arrest of Herbert seem purely incidental. It now looks as if there would be another arrest of a--of a person who is so high socially, and all that----"

"Yes," interrupted The Thinking Machine, "but do you think it would be wise to arrest her now?"

"Her?" demanded Detective Mallory. "What do you know of any woman?"

"You were speaking of Miss Dorothy Meredith, weren't you?" inquired The Thinking Machine blandly. "Well, I merely asked if you thought it would be wise for your men to go so far as to arrest her."

The detective bit his cigar in two in obvious perturbation.

"How--how--did you happen to know her name?" he demanded.

"Oh, Mr. Hatch mentioned it to me," replied the scientist. "He has known of her connection with the case for several days, as well as Herbert's, and has talked to them both, I think."