“So you fetched old Harker?” he said. “What--what for, doctor? If one may ask, you know.” Bryce made a careless gesture with his cigarette. “Oh--old Harker's deeply interested in what's going on,” he answered. “And as young Bewery drew my attention to your proceedings, why, I thought I'd draw Harker's. And Harker was--interested.” Mitchington hesitated before saying more. But eventually he risked a leading question. “Any special reason why he should be, doctor?” he asked. Bryce put his thumbs in the armholes of his waistcoat and looked half-lazily at his questioner. “Do you know who old Harker really is?” he inquired. “No!” answered Mitchington. “I know nothing about him--except that he's said to be a retired tradesman, from London, who settled down here some time ago.” Bryce suddenly turned on Jettison. “Do you?” he asked. “I, sir!” exclaimed Jettison. “I don't know this gentleman--at all!” Bryce laughed--with his usual touch of cynical sneering. “I'll tell you--now--who old Harker is, Mitchington,” he said. “You may as well know. I thought Mr. Jettison might recognize the name. Harker is no retired London tradesman--he's a retired member of your profession, Mr. Jettison. He was in his day one of the smartest men in the service of your department. Only he's transposed his name--ask them at the Yard if they remember Harker Simpson? That seems to startle you, Mitchington! Well, as you're here, perhaps I'd better startle you a bit more.” CHAPTER XIX. THE SUBTLETY OF THE DEVIL There was a sudden determination and alertness in Bryce's last words which contrasted strongly, and even strangely, with the almost cynical indifference that had characterized him since his visitors came in, and the two men recognized it and glanced questioningly at each other. There was an alteration, too, in his manner; instead of lounging lazily in his chair, as if he had no other thought than of personal ease, he was now sitting erect, looking sharply from one man to the other; his whole attitude, bearing, speech seemed to indicate that he had suddenly made up his mind to adopt some definite course of action. “I'll tell you more!” he repeated. “And, since you're here--now!” Mitchington, who felt a curious uneasiness, gave Jettison another glance. And this time it was Jettison who spoke. “I should say,” he remarked quietly, “knowing what I've gathered of the matter, that we ought to be glad of any information Dr. Bryce can give us.” “Oh, to be sure!” assented Mitchington. “You know more, then, doctor?” Bryce motioned his visitors to draw their chairs nearer to his, and when he spoke it was in the low, concentrated tones of a man who means business--and confidential business.