Deep in their hearts lurked a fear that something had gone wrong--which thought was suggested by the sounds of the shooting they had heard.
Singleton had become afflicted with the nervousness that had seized Warden.

The pout on his lips grew; he cast startled, inquiring glances toward the door.

And at last, as they stood silent, looking at each other, there came a sound--close; the sound of a man walking in the street.

As they listened the sound came closer, reached the front of the building.

Then they heard it on the stairs.