“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 XIGurther

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 . . .