“Urgent. See Seven at E.S.2. No raid. Get M.’s statement. Urgent. F.1.” Dick took the paper from his subordinate’s hand and read it. “He’s wrong about the no raid,” he said. “E. S., of course, is Eldor Street, and two is either the number two or two o’clock.” “Who’s ‘M.’?” asked Elk, frowning. “Obviously Mills—the man we caught at Wandsworth. He made a written statement, didn’t he?” “He has signed one,” said Elk thoughtfully. He turned the papers over, and after a while found what he was looking for—a small envelope. It was addressed in typewritten characters to “G. V. Hagn,” and bore on the back the stamp of the District Messenger service. The staff were still held by the police, and Elk sent for the doorkeeper. “What time was this delivered?” he asked. The man was an ex-soldier, the only one of the prisoners who seemed to feel his position. “It came at about nine o’clock, sir,” he said readily, and produced the letter-book in confirmation. “It was brought by a District Messenger boy,” he explained unnecessarily. “Does Mr. Hagn get many notes by District Messenger?” “Very few, sir,” said the doorkeeper, and added an anxious inquiry as to his own fate. “You can go,” said Elk. “Under escort,” he added, “to your own home. You’re not to communicate with anybody, or tell any of the servants here that I have made inquiries about this letter. Do you understand?” “Yes, sir.” To make assurance doubly sure, Elk had called up exchange and placed a ban upon all ’phone communications. It was now a quarter to two, and, leaving half-a-dozen detectives in charge of the club, he got the remainder on to the car that had brought them, and, accompanied by Dick, went full speed for Tottenham. Within a hundred yards of Eldor Street the car stopped and unloaded. The first essential was that whoever was meeting No. 7 in Eldor Street should not be warned of their approach. It was more than possible that Frog scouts would be watching at each end of the street. “I don’t know why they should,” said Elk, when Dick put this possibility forward. “I can give you one very excellent reason,” said Dick quietly. “It is this: that the Frogs know all about your previous visit to Maitland’s slum residence.” “What makes you think that?” asked Elk in surprise, but Dick did not enlighten him. Sending the men round by circuitous routes, he went forward with Elk, and at the very corner of Eldor Street, Elk found that his chief’s surmise was well founded. Under a lamp-post Elk saw the dim figure of a man standing, and instantly began an animated and raucous conversation concerning a mythical Mr. Brown. Realizing that this was intended for the watcher, Gordon joined in. The man under the lamp-post hesitated just a little too long. As they came abreast of him, Elk turned. “Have you got a match?” he asked. “No,” growled the other, and the next instant was on the ground, with Elk’s knee on his chest and the detective’s bony hand around his throat.