There was nothing visible, but the interior was dark and forbidding. Waldo felt cold and clammy. He began to tremble. Then he turned and looked back toward the forest.
The thought of another night spent within sight of that dismal place almost overcame him. No! A thousand times no! Any fate were better than that, and so after several futile efforts he forced his unwilling body through the small aperture.
He found himself on a path between two rocky walls—a path that rose before him at a steep angle. At intervals the blue sky was visible above through openings that had not been filled with debris.
To another it would have been apparent that the cleft had been kept open by human beings—that it was a thoroughfare which was used, if not frequently, at least sufficiently often to warrant considerable labor having been expended upon it to keep it free from the debris which must be constantly falling from above.
Where the path led, or what he expected to find at the other end, Waldo had not the remotest idea. He was not an imaginative youth. But he kept on up the ascent in the hope that at the end he would find the creature which had escaped him the night before.
As it had fled for a brief instant across the clear-
