little—a very little. He walked on up Park Avenue to Thirty-seventh Street, turned in there and entered a house about the middle of the block, with a latch-key. The detective glanced at the number of the house, and felt aggrieved—it was the number that was written in the note! And Mr. Wynne had entered with a key! Which meant, in all probability, that he did live there, as he had said!

But why did he take that useless cab ride up Fifth Avenue? If he had no objection to any one knowing his address, why did he go so far out of his way? Mr. Birnes couldn't say. As he pondered these questions he saw a maid-servant come out of a house adjoining that which Mr. Wynne had entered, an he went up boldly to question her.

Did a Mr. Wynne live next door? Yes. How long had he lived there? Five or six months. Did he own the house? No. The people who owned the house had gone to Europe for a year and had rented it furnished. No, Mr. Wynne didn't have a family. He lived there alone except for two servants, a cook and a housemaid. She had never noticed anything unusual about Mr. Wynne, or the servants, or the house. Yes, he went out every day, downtown to business. No, she didn't know what his business was, but she had an idea that he was a broker. That was all.

From a near-by telephone booth the detective detailed Claflin and Malone, who had returned to the office, to keep a sharp watch on the house, after which he walked on to Fifth Avenue, and down Fifth Avenue to the establishment of the H. Latham Company. Mr. Latham would see him—yes. In fact, Mr. Latham, harried by the events of the past two hours, bewildered by a hundred-million-dollar diamond deal which had been thrust down his throat gracefully, but none the less certainly, and ridden by the keenest curiosity, was delighted to see Mr. Birnes.

"I've got his house address all right," Mr. Birne boasted, in the beginning. Of course it was against the ethics of the profession to tell how he got it.

"Progress already," commented Mr. Latham with keen interest. "That's good."

Then the detective detailed the information he had received from the maid, adding thereto divers and sundry conclusions of his own.

Mr. Latham marveled exceedingly.

"He tried to shake us all right when he went out," Mr. Birnes went on to explain, "but the trap was set and there was no escape."

With certain minor omissions he told of the cab ride to Sixty-seventh Street, the trip across to a downtown car, and, as a matter of convincing circumstantial detail, added the incident of the empty gripsack.

"Empty?" repeated Mr. Latham, startled. "Empty, did you say?"

"Empty as a bass drum," the detective assured him complacently. "He turned it upside down and shook it."

"Then what became of them?" demanded Mr. Latham.

"Became of what?"

"The diamonds, man—what became of the diamonds?"

"You didn't mention any diamonds to me except those five the other day," the detective reminded him coldly. "Your instructions were to find out all about this man—who he is, what he does, where he goes, and the rest. This is my preliminary report. You didn't mention diamonds."

"I didn't know he would have them," Mr. Latham exploded irascibly. "That empty gripsack, man—when he left here he carried millions—I mean a great quantity of diamonds in it."

"A great quantity of —," the detective began; and then he sat up straight in his chair and stared at Mr. Latham in bewilderment.

"If the gripsack was empty when he was on the car," Mr. Latham rushed on excitedly, "then don't you see that he got rid of the diamonds somehow from the time he left here until you saw that the gripsack was empty? How did he get rid of them? Where does he keep them? And where does he get them?"

Mr. Birnes closed his teeth grimly and his eyes snapped. Now he knew why Mr. Wynne had taken that useless cab ride up Fifth Avenue. It was to enable him to get rid of the diamonds! There was an accomplice—in detective parlance the second person is always an accomplice—in that closed cab! It had all been prearranged; Mr. Wynne had deliberately made a monkey of him—Steven Birnes! Reluctantly the detective permitted himself to remember that he didn't know whether there was anybody in that cab or not when Mr. Wynne entered it, and—and—! Then he remembered that he did know one thing—the number of the cab!

He arose abruptly, with the light of a great determination in his face.

"Whose diamonds were they?" he demanded.

"They were his, as far as we know," replied Mr. Latham.

"How much were they worth?"

Mr. Latham looked him over thoughtfully.

"I am not at liberty to tell you that, Mr. Birnes," he said at last. "There are a great number of them, and they are worth—they are worth a large sum of money. And they are all unset. That's enough for you to know, I think."

It seemed to be quite enough for Mr. Birnes to know.

"It may be that I will have something further to report this evening," he told Mr. Latham. "If not, I'll see you to-morrow, here."

He went out. Ten minutes later he was talking to a friend in police headquarters, over the telephone. The records there showed that the license for the particular cab he had followed had been issued to one William Johns. He was usually to be found around the cabstand in Madison Square, and lived in Charlton Street.

CHAPTER VI

THE MYSTERIOUS WOMAN

Mr. Birnes' busy heels fairly spurned the pavements of Fifth Avenue as he started toward Madison Square. Here was a long line of cabs drawn up beside the curb, some twenty or thirty in all. The fifth from the end bore the number he sought—Mr. Birnes chuckled; and there, alongside it, stood William Johns, swapping Billingsgate with the driver of a hansom, the while he kept one eye open for a prospective fare. It was too easy! Mr. Birnes paused long enough to congratulate himself upon his marvelous acumen, and then he approached the driver.

"You are William Johns?" he accused him sharply.

"That's me, Cap," the cabby answered readily.

"A few minutes past four o'clock this afternoon you went up Fifth Avenue, and stopped at the corner of Thirty-fourth Street to pick up a fare—a young man."

"Yep."

"You drove him to the corner of Sixty-seventh Street and Fifth
Avenue," the detective went on just to forestall possible denials.
"He got out there, paid you, and you went on up Fifth Avenue."

"Far be it from me to deceive you, Cap," responded the cabby with irritating levity. "I done that same."

"Who was that man?" demanded Mr. Birnes coldly.

"Search me! I never seen him before."

The detective regarded the cabby with accusing eyes. Then, quite casually, he flipped open his coat and Johns caught a glimpse of a silver shield. It might only have been accident, of course, still—

"Now, Johns, who was the man in the cab when you stopped to pick up the second man at Thirty-fourth Street?"

"Wrong, Cap," and the cabby grinned. "There wasn't any man."

"Don't attempt to deny—"

"No man, Cap. It was a woman."

"A woman!" the detective repeated. "A woman!"

"Sure thing—a woman, a regular woman. And, Cap, she was a pippin, a peachorino, a