There are two entrances to Scotland Yard: one that opens into Whitehall and was by far the best route for him, since Whitehall is filled with cabs; the other on to the Thames Embankment, which, in addition to offering the longest way round, would bring him to a thoroughfare where, at this hour of the night, taxis would be few and far between. So engrossed was Elk with his thoughts that he was on the Embankment before he realized where he was going. He turned toward the Houses of Parliament into Bridge Street, found an ancient cab and gave the address. The driver was elderly and probably a little fuddled, for, instead of stopping at No. 273, he overshot the mark by a dozen houses, and only stopped at all on the vitriolic representations of his fare. “What’s the matter with you, Noah?—this ain’t Mount Ararat!” snapped Elk as he descended. “You’re boozed, you poor fish.” “Wish I was,” murmured the driver, holding out his hand for the fare. Elk would have argued the matter but for the urgency of the summons. Whilst he was waiting for the driver to unbutton his many coats to find change, he glanced back along the street. A car was standing near the door of Dick Gordon’s house, its headlights dimmed to the least possible degree. That in itself was not remarkable. The two men who waited on the pavement were. They stood with their backs to the railings, one (as he guessed) on either side of the door. To him came the soft purring of the motor-car’s engine. He took a step back and brought the opposite pavement into his range of vision. There were two other men, also lounging idly, and they were exactly opposite 273. Elk looked round. The cab had stopped before a doctor’s house, and the detective did not take a long time to make up his mind. “Wait till I come out.” “Don’t be long,” pleaded the aged driver. “The bars will be shut in a quarter of an hour.” “Wait, Batchus,” said Elk, who had a nodding acquaintance with ancient mythology, but only a hazy idea of pronunciation. Bacchus growled, but waited. Fortunately, the doctor was at home, and to him Elk revealed his identity. In a few seconds he was connected with Mary Lane Police Station. “Elk, Central Office, speaking,” he said rapidly, and gave his code number. “Send every man you can put your hand on, to close Harley Terrace north and south of 273. Stop all cars from the moment you get my signal—two long two short flashes. How soon can your men be in place?” “In five minutes, Mr. Elk. The night reliefs are parading, and I have a couple of motor-trucks here—just pinched the drivers for being drunk.” He replaced the receiver and went into the hall. “Anything wrong?” asked the startled doctor as Elk slid back the jacket of his automatic and pushed the safety catch into place. “I hope so, sir,” said Elk truthfully. “If I’ve turned out the division because a few innocent fellows are leaning against the railings of Harley Terrace, I’m going to get myself into trouble.”