Elk had guessed right. The inquiry about the key was prearranged. A telephone message to Mary Lane, where the remainder of the gang were held, produced the curious information that a woman, reputedly the wife of one of the men, had called that morning, and, on being refused an interview, begged for news about the missing key of the coal cellar, and had been told that it was in the possession of “the Brixton man.” “The men are to be remitted to Wormwood Scrubbs Prison, and they are not to be told where they are going,” ordered Elk. That afternoon a horse-driven prison-van drew out of Cannon Row and rumbled along Whitehall. At the juncture of St. Martin’s Lane and Shaftesbury Avenue, a carelessly-driven motor lorry smashed into its side, slicing off the near wheel. Instantly there came from nowhere a crowd of remarkable appearance. It seemed as if all the tramps in the world had been lying in wait to crowd about the crippled van. The door was wrenched open, and the gaoler on duty hauled forth. Before he could be handled, the van disgorged twenty Central Office men, and from the side streets came a score of mounted policemen, clubs in hand. The riot lasted less then three minutes. Some of the wild-looking men succeeded in making their escape, but the majority, chained in twos, went, meekly enough, between their mounted escorts. Dick Gordon, who was also something of an organizer, watched the fight from the top of an omnibus, which, laden with policemen, had shadowed the van. He joined Elk after the excitement had subsided. “Have you arrested anybody of importance?” he asked. “It’s too early to say,” said Elk. “They look like ordinary tadpoles to me. I guess Litnov is in Wandsworth by now—I sent him in a closed police car before the van left.” Arrived at Scotland Yard, he paraded the Frogs in two open ranks, watched, at a distance, by the curious crowd which packed both entrances. One by one he examined their wrists, and in every case the tattoo mark was present. He finished his scrutiny at last, and his captives were herded into an inner yard under an armed guard. “One man wants to speak to you, sir.” The last file had disappeared when the officer in charge reported, and Elk exchanged a glance with his chief. “See him,” said Dick. “We can’t afford to miss any information.” A policeman brought the Frog to them—a tall man with a week’s growth of beard, poorly dressed and grimy. His battered hat was pulled down over his eyes, his powerful wrists visible beneath the sleeves of a jacket that was made for a smaller man. “Well, Frog?” said Elk, glowering at him. “What’s your croak?” “Croak is a good word,” said the man, and at the sound of his voice Elk stared. “You don’t think that old police car of yours is going to reach Wandsworth, do you?” “Who are you?” asked Elk, peering forward.