They no longer heard sounds--nothing but the crumbling and falling of dust and pebbles where the bullets had struck, and their own heart-beats.

The picks and rock-hammers had ceased.
Tighter and tighter grew the clasp of Joanne's fingers, and a terrible thought flashed into John's brain.

Perhaps a, rock from the slide had cut a wire, and they had found the wire--had repaired it! Was that thought in Joanne's mind, too?
Her finger-nails pricked his flesh.

He looked at her.
Her eyes were closed, and her lips were tense and gray.

And then her eyes shot open--wide and staring.