He ran up the stairs to the top floor, and on the landing, outside an attic door, pulled at a rope. A fire ladder lying flat against the ceiling came down, and at the same time a small skylight opened. Leon went into the room, and his pocket-lamp located what he needed: a small papier-mâché cylinder, not unlike a seven-pound shell. With this on his arm, he climbed up the ladder on to the roof, fixed the cylinder on a flat surface, and, striking a match, lit a touch-paper. The paper sizzled and spluttered, there was a sudden flash and “boom!” a dull explosion, and a white ball shot up into the sky, described a graceful curve and burst into a shower of brilliant crimson stars. He waited till the last died out; then, with the hot cylinder under his arm, descended the ladder, released the rope that held it in place, and returned to his two friends. “They will imagine a secret arrangement of signals with the police,” he said; “unless my knowledge of their psychology is at fault, we shall not be bothered again.” Ten minutes later there was another knock at the door, peremptory, almost official in its character. “This,” said Leon, “is a policeman to summon us for discharging fireworks in the public street!” He ran lightly down into the hall and without hesitation pulled open the door. A tall, helmeted figure stood on the doorstep, notebook in hand. “Are you the gentleman that let off that rocket——” he began. Leon walked past him, and looked up and down Curzon Street. As he had expected, the Old Guard had vanished. _Chapter XI_ _Gurther_ MONTY NEWTON dragged himself home, a weary, angry man, and let himself in with his key. He found the footman lying on the floor of the hall asleep, his greatcoat pulled over him, and stirred him to wakefulness with the toe of his boot. “Get up,” he growled. “Anybody been here?” Fred rose, a little dazed, rubbing his eyes. “The old man’s in the drawing-room,” he said, and his employer passed on without another word. As he opened the door, he saw that all the lights in the drawing-room were lit. Dr. Oberzohn had pulled a small table near the fire, and before this he sat bolt upright, a tiny chess-board before him, immersed in a problem. He looked across to the new-comer for a second and then resumed his study of the board, made a move . . . “Ach!” he said in tones of satisfaction. “Leskina was wrong! It is possible to mate in five moves!” He pushed the chess-men into confusion and turned squarely to face Newton. “Well, have you concluded these matters satisfactorily?” “He brought up the reserves,” said Monty, unlocking a tantalus on a side table and helping himself liberally to whisky. “They got Cuccini through the jaw. Nothing serious.” Dr. Oberzohn laid his bony hands on his knees.