An hour later, a detective brought a grimy-looking prisoner into Cannon Row and pushed him into the steel pen, and the only man who recognized the prisoner was the chief inspector who had waited for the arrival of the pigeon. It was that high official himself who conducted Balder to the separate cell and pushed him in. “Good night, Frog!” he said. Balder’s reply was unprintable. After seeing his subordinate safely caged, Elk went back to his room, locked the door, cut off his telephone and lay down to snatch a few hours’ sleep. It was a practice of his, when he was engaged in any work which kept him up at night, to take these intermediate siestas, and he had trained himself to sleep as and when the opportunity presented itself. It was unusual in him, however, to avail himself of the office sofa, a piece of furniture to which he was not entitled, and which, as his superiors had often pointed out, occupied space which might better be employed. For once, however, he could not sleep. His mind ranged from Balder to Dick Gordon, from Lola Bassano to the dead man Mills. His own position had been seriously jeopardized, but that worried him not at all. He was a bachelor, had a snug sum invested. His mind went to the puzzling Maitland. His association with the Frogs had been proved almost up to the hilt. And Maitland was in a position to benefit by these many inexplicable attacks which had been made upon seemingly inoffensive people. The old man lived a double life. By day the business martinet, before whom his staff trembled, the cutter of salaries, the shrewd manipulator of properties; by night the associate of thieves and worse than thieves. Who was the child? That was another snag. “Nothing but snags!” growled Elk, his hands under his head, looking resentfully at the ceiling. “Nothing but snags.” Finding he could not sleep, he got up and went across to Cannon Row. The gaoler told him that the new prisoner had been talking a lot to Hagn, and Elk grinned. He only hoped that the “new prisoner” would not be tempted to discuss his grievances against the police administration. At a quarter to three he joined Dick Gordon in the instrument room at the Admiralty. An operator had been placed at their disposal; and after the preliminary instructions they took their place at the table where he manipulated his keys. Dick listened, fascinated, hearing the calls of far-off ships and the chatter of transmitting stations. Once he heard a faint squeak of sound, so faint that he wasn’t sure that he had not been mistaken. “Cape Race,” said the operator. “You’ll hear Chicago in a minute. He usually gets talkative round about now.” As the hands of the clock approached three, the operator began varying his wave lengths, reaching out into the ether for the message which was coming. Exactly at one minute after three he said suddenly: “There is your L.V.M.B.” Dick listened to the staccato sounds, and then: