On their right the wall of the mountain closed in rapidly, and as they stumbled with their burden over a mass of huge boulders the two boys saw just ahead of them the narrow trail at the edge of the precipice.
At its beginning they rested their canoe.

On one side of them, a dozen yards away, the face of the mountain rose sheer above them for a thousand feet; on the other, scarce that distance from where they stood, was the roaring chasm.

And ahead of them the mountain wall and the edge of the precipice came nearer and nearer, until there was no more than a six-foot ledge to walk upon.

Rod's face turned strangely white as he realized, for the first time, the terrible chances they had taken on that black, eventful night of a few months ago; and for a time Wabi stood silent, his face as hard-set as a rock.

Up out of the chasm there came a deafening thunder of raging waters, like the hollow explosions of great guns echoing and reechoing in subterranean caverns.
"Let's take a look!" shouted Wabi close up to his companion's ear.
He went to the edge of the precipice, and Rod forced himself to follow, though there was in him a powerful inclination to hug close to the mountain wall.