After some thought he determined to follow up the doctor’s clue and next morning he went to Peebles. There he had little difficulty in finding Roper’s mother. She kept a huckster’s shop in the poorer part of the town, but it was evident that she was getting too old for the work, and that business was not flourishing. She was suspicious at first, but under the genial influence of French’s manner she thawed and presently became garrulous. French was soon satisfied that she had no idea that her son might be alive. He pumped her with his usual skill, pretending he was a former acquaintance of Roper’s, but in the end also he was unable to learn anything helpful. He returned to Thirsby and began a series of inquiries at the nearby railway stations, posting establishments, inns and villages, in the hope of coming on some trace of the quarry. But the trail was too old. For three days he worked early and late, but nowhere did he learn of any mysterious stranger who might prove to be the missing man. He was indeed about to give up in despair, when his labours were brought to an unexpected conclusion. Chief Inspector Mitchell wired an urgent recall to the Yard. It was by no means the first of such recalls that French had received, though it was not usual to interrupt an officer who was actually engaged in investigating a case. The incident always bred a slight uneasiness. The possibility of having made some serious blunder was ever present. And French was aware that his most unhappy experiences had almost invariably followed periods of exaltation and self-satisfaction. Chief Inspector Mitchell was an exceedingly shrewd man and he had a perfectly uncanny way of delving to the bottom of problems and of seeing clues that other people missed. French earnestly hoped that it was not so in the present instance. He travelled up by the night train and early next morning reported at the Yard. There he found his fears were groundless. The Chief Inspector, so far from grumbling, was in a very good mood and almost complimented him on what he had done. “Well, French, you’re up against it again, are you? What were you busy at when you got my wire?” French explained. “You can do something better. Read that.” It was the typewritten note of a telephone conversation. It appeared that at four o’clock on the previous evening the manager of the Northern Shires Bank in Throgmorton Avenue had rung up to say that two twenty-pound notes bearing numbers on the list supplied in connection with the Starvel Hollow crime had been passed into the bank that afternoon. The cashier had just at that moment made the discovery, but unfortunately he was unable to remember from whom he had received them. “By Jove, sir!” French exclaimed. “Then Roper is in town!”