He saw the form leap from the rocks at its edge, heard a heavy splash, and all was still! For many minutes Rod stood with the spray of the cataract dashing in his face.

This time the madman's plunge into the cold depths at his feet filled him with none of the horror of that first insane leap from the rock above.

Somewhere in that pool the old man was seeking refuge! What did it mean?
His eyes scanned the thin sheet of water that plunged down from the upper chasm.

It was a dozen feet in width and hid the black wall of rock behind it like a thick veil.

What was there just behind that falling torrent?
Was it possible that in the wall of rock behind the waterfall there was a place where John Ball found concealment?
Rod returned to camp, convinced that he had at last guessed a solution to the mystery.