But as the two scrambled along the foot, they passed deep-cut gullies and fissures, most of them unclimbable, but offering something more hopeful than the face.

At one of these Old Bill halted, and led the way up and over a chaos of fallen rock and loose sand.

The grey weather had brought on the dark prematurely, and in the half-light it seemed that this ravine was blocked by an unscalable nose of rock.

Here Old Bill whistled, and there was a reply from above.

Round the corner of the nose came Dougal.
"Up here," he commanded.