He waited there, motionless and breathless, as that silence of only a few seconds prolonged itself into something which to his straining nerves seemed almost interminable.
Then, above the din of the Alambo's many activities, came still another sound. It was not loud. It was a sound not unlike that of one board being dropped flat on another, or of two books being slapped together to rid them of dust.
It was a sound that might have been accepted as the distant explosion of gases in the exhaust of a back-firing automobile, or, to the uninitiated ear, as the quick slam of a door. But to Kestner it meant something quite different. It was a sound which he had heard on more than one occasion, and always with a feeling of nettling nerve-ends.
Almost before the meaning of that sound had fully registered itself on his startled consciousness there was a second and less determinate sound. The floor under Kestner's feet quivered a little with the concussion of some sudden weight imposed upon it.
But the Secret Agent no longer stood there inactive. That tell-tale thud brought his hand up to the brass draw-bolt. Even when this was released, however, he found the door still locked. He could not distinctly remember whether he cried out or not. But he at least knew that he was struggling and straining ineffectually against a locked door, and losing valuable time.
Then he wheeled about and ran back into the centre of the room. There he caught up a slattern-cushioned arm-chair, letting the cushions fall about
