The Flying Squad man grumblingly saw common sense in this. All the same as Labar quietly stole up to the narrow doorway and crept within, he collected two or three men and with them posted himself, so that a swift and sudden rush could be made after his friend if necessary.

It was almost pitch-black within. Labar felt his way along the wall till he came to the foot of the stairs and then paused to listen. He could detect no sound in the house. He dropped to his hands and knees and stealthily ascended the first step, registering a mental oath as it creaked under him. He remembered that he had failed to retrieve the pistol that he had lent to Dr. Ware. Well, that would not matter much. He was not relying on gunplay.

Inch by inch he crawled to the first landing and moved up the second flight. Not till he had reached the third flight, however, could he detect the sound of a man’s hurried, irregular breathing. He flattened himself as closely as he could to the outline of the stair and waited, listening, for a second or two. Then he raised his voice sharply.