A CHAMBER OF HORROR I backed against the wall, crouching low, revolver in hand, scarcely venturing to breathe, listening intently for the slightest sound to break the intense silence.

My heart beat like a trip-hammer, and there were beads of cold perspiration on my face.

The change had occurred so swiftly as to leave me quaking like a coward at the unknown terrors of the dark.

Yet almost within the instant I gripped my nerves, comprehending all that had occurred, and confident of my own safety.
There must be another opening into this underground den--one leading to the outer air--judging from that sudden and powerful suction.

The very atmosphere I breathed had a freshness to it, inconceivable in such a place otherwise.