He stood like a sentinel, weapon in hand, staring into the awful darkness, struggling against its oppression, fighting to keep his brain alert and ready for any emergency.

He thought he was prepared for anything, but that time of waiting tried his endurance to the utmost, and when at length a sound other than that irregular drip of water came through the deathly stillness he started with a violence that sent a smile of self-contempt to his lips.
It was a wholly unexpected sound--just the ordinary tones of a man's voice speaking to him through the darkness where he had believed that there was nothing but a blank wall.
"Mr.Hill, where are you ?" it said.

"I have come to get you out." Hill's hand tightened upon his revolver.

He was not to be taken unawares a second time.

He stood in absolute silence, waiting.
There was a brief pause, then again came the voice.