He waited five minutes, then opened the door and went out. The men were still in their positions, and as he stood there two motor-trucks drove into the thoroughfare from either end, turned broadside in the middle of the road and stopped. Elk’s pocket lamp flashed to left and right, and he jumped for the pavement. And now he saw that his suspicions were justified. The men on the opposite pavement came across the road at the double, and leapt to the running-board of the car with the dim lights as it moved. Simultaneously the two who had been guarding the entrance of 273 sprang into the machine. But the fugitives were too late. The car swerved to avoid the blocking motor-truck, but even as it turned, the truck ran backwards. There was a crash, a sound of splintering glass, and by the time Elk arrived, the five occupants of the car were in the hands of the uniformed policemen who swarmed at the end of the street. The prisoners accepted their capture without resistance. One (the chauffeur) who tried to throw away a revolver unobtrusively, was detected in the act and handcuffed, but the remainder gave no trouble. At the police-station Elk had a view of his prisoners. Four very fine specimens of the genus tramp, wearing their new ready-to-wear suits awkwardly. The fifth, who gave a Russian name, and was obviously the driver, a little man with small, sharp eyes that glanced uneasily from face to face. Two of the prisoners carried loaded revolvers; in the car they found four walking-sticks heavily weighted. “Take off your coats and roll up your sleeves,” commanded the inspector. “You needn’t trouble, Elk.” It was the little chauffeur speaking. “All us boys are good Frogs.” “There ain’t any good Frogs,” said Elk. “There’s only bad Frogs and worse Frogs and the worst Frog of all. But we won’t argue. Let these men into their cells, sergeant, and keep them separate. I’ll take Litnov to headquarters.” The chauffeur looked uneasily from Elk to the station sergeant. “What’s the great idea?” he asked. “You’re not allowed to use the third degree in England.” “The law has been altered,” said Elk ominously, and re-snapped the handcuffs on the man’s wrists. The law had not been altered, but this the little Russian did not know. Throughout the journey to headquarters he communed with himself, and when he was pushed into Elk’s bare-looking room, he was prepared to talk. . . . Dick was waiting for the detective when he came back to Harley Terrace, and heard the story. “I never dreamt that it was a plant until I spotted the lads waiting for me,” said Elk. “Of course you didn’t telephone; they caught me napping there. Thorough! The Frogs are all that! They expected me to leave headquarters by the Whitehall entrance, and had a taxi waiting to pick me up, but in case they missed me that way, they told off a party to meet me in Harley Terrace. Thorough!” “Who gave them their orders?” Elk shrugged.