“They’re all blind,” said Elk in a whisper. “And that is Balder’s own broadcasting apparatus, and the aerial is attached to the lamp.” The three servants went out, and, rising, Balder walked to the door and locked it. There were another set of windows in the room, looking out upon the side of the house, and one by one Balder closed and shuttered them. He was busy with the second of the three, when Elk put his foot upon a ledge of brick, and, tearing aside the curtain, leapt into the room. At the sound, Balder spun round. “Evening, Balder,” said Elk. The man made no reply. He stood, watching his sometime chief, with eyes that did not waver. “Thought I’d come along and tell you that you’ve got your promotion,” said Elk, “as Acting-Sergeant from the 1st of May, in recognition of the services you’ve rendered to the State by poisoning Frog Mills, loosing Frog Hagn, and blowing up my office with a bomb that you planted overnight.” Still the man did not speak, nor did he move; and here he was discreet, for the long-barrelled Browning in Elk’s hand covered the lower button of his white piqué waistcoat. “And now,” said Elk—there was a ring of triumph in his voice—“you’ll take a little walk with me—I want you, _Number Seven_!” “Haven’t you made a mistake?” drawled Balder, so unlike his usual voice that Elk was for a moment taken aback. “I never have made a mistake except about the date when Henry the Eighth married,” said Elk. “Who do you imagine I am?” asked this debonair man of the world. “I’ve ceased imagining anything about you, Balder—I know!” Elk walked with a quick movement toward him and thrust the muzzle of the pistol in his prisoner’s diaphragm. “Put up your hands and turn round,” he said. Balder obeyed. Slipping a pair of handcuffs from his pocket, Elk snapped them on to the wrists. Deftly the detective strapped the arms from behind, drawing them tight, so that the manacled hands had no play. “This is very uncomfortable,” said Balder. “Is it usual for you to make mistakes of this character, Mr. Elk? My name is Collett-Banson.” “Your name is Mud,” said Elk, “but I’m willing to listen to anything you like to say. I’d rather have your views on cyanide of potassium than anything. You can sit down.” Dick saw a gleam come to the man’s eye; it flashed for a second and was gone. Evidently Elk saw it too. “Don’t let your hopes rest upon any monkey tricks that might be played by your attendants,” he said, “because fifty C.I.D. men, most of whom are known personally to you, are disposed round this house.” Balder laughed. “If they were round the house and on top of the house, they wouldn’t worry me,” he said. “I tell you, inspector, you’ve made a very grave error, and one which will cost you dear. If a gentleman cannot sit in his own drawing-room”—he glanced at the table—“listening to a wireless concert at The Hague without interfering policemen—then it is about time the police force was disbanded.”