"Not you certainly, old man," replied Sturgis, smiling. "Don't worry; you have not voluntarily betrayed any professional secret. But, for all that, your patient is wanted by the police. He was bound to fall into their hands before long. The only effect of this discovery will be to hasten the dénouement. I had traced him to your house, and I knew how he was wounded; so that I recognized him as soon as you mentioned his case." "Who is he?" asked Thurston. "I am sure I have seen him somewhere before; but I cannot remember where." Whereupon the reporter related the story of Chatham's connection with the Knickerbocker bank case. CHAPTER XVII. THE QUARRY. Half an hour later, Sturgis was walking briskly down Broadway, with his usual air of absent-minded concentration. Presently he turned into a side street and at once slackened his pace. He now sauntered along like a lounger at a loss how to kill a long idle day. The show window of a bric-à-brac shop arrested his attention. He stopped to examine its contents. A little farther up the street was a liquor saloon, outside of which stood a group of boisterous young rowdies. An older man, evidently in his cups, was seated on an adjoining stoop, where, with maudlin gravity, he seemed to be communing with himself. On the opposite side of the way stood a low, dilapidated brick house. A painted sign over the windows of the ground floor bore the name, "MANHATTAN CHEMICAL CO." The drunken man rose unsteadily to his feet and approached Sturgis with outstretched hand. "Say, Jimmy, get on ter his nibs strikin' de bloke fur a nickel ter git med'cine fur his sick mudder," exclaimed one of the young ruffians. The wretched-looking individual thus designated seemed hardly able to stand as he steadied himself against an iron railing; but the eyes he turned upon Sturgis were bright with intelligence, and the words he spoke were uttered in a low, firm voice. "He's been here--been here twice." "Twice?" echoed Sturgis, surprised. "Where is he now?" "I don't know----" "You don't know?" "No, sir; but I guess Conklin does. This is how it is: It was my watch yesterday afternoon when Chatham came the first time. He went into the Manhattan Company's place through the basement at a quarter after five. So I just settled myself out here and waited. Well, I waited and waited, but there wasn't any sign of Chatham, and when Flagler came along to relieve me at ten o'clock Chatham hadn't come out yet. Flagler he spotted the place until six this morning, and then Conklin took his turn again until two o'clock, when I came on for my watch. Just as Conklin was telling me how things stood, who should come down the street but Chatham himself, large as life." "Down the street?" exclaimed Sturgis. "Yes, sir. And up he goes, as if nothing had happened, and into the Manhattan Chemical Company's place again."