"This trail appears to have been made by man," said Nur An.
"Whoever made it, or when," I said, "there is no doubt but that some creature still uses it. The absence of fruit along it would alone be ample proof of that."
We moved cautiously along the winding trail, not knowing at what moment we might be confronted by some new menace in the form of man or beast. Presently we saw ahead of us what appeared to be an opening in the forest, and a moment later we emerged into a clearing. Looming in front of us at a distance of perhaps less than a haad was a towering pile of masonry. It was a gloomy pile, apparently built of black volcanic rock. For some thirty feet above the ground there was a blank wall, pierced by but a single opening—a small doorway almost directly in front of us. This part o
