Sid, the educated white boy, had become so interested in reconstructing the geological aspects of this formation that he almost forgot the irksome tightness of the thongs that still bound his arms and the almost certain death to which he was being led. He knew only too well from border history the ways of the wild Apache! But the Indian guard behind him had no other thought but his duty as jailer. While Sid’s wondering eyes were scanning that giant apron of lava that flowed down out of Red Mesa, the Apache suddenly spun him violently around. Sid had one whirling glimpse of a small black opening in the lava above, looking like a ragged mouth, and his curiosity about it had just begun to leap up overthrowing the greater marvel of the whole cataclysm of Red Mesa, when his head was forcibly held from turning and his bandanna was whipped deftly across his eyes. The sandy plain below disappeared from view, and in its place was now an impenetrable blackness. Presently he felt the grip of two firm hands on his elbows. A vigorous push set his feet in motion to hold his balance. By the shortness of his step and the upward lift of it Sid knew they were climbing again. Often the Indian stooped down and took hold of his ankles to guide his footsteps to some secure place. Sid could tell by the opprobrious epithets in Apache with which the young fellow belabored him that he scorned Sid’s blind clumsiness and was angry and intolerant, but Sid made no sign that he understood the language. Once, though, he nearly gave himself away, when the buck shouted “Right!” sharply in Apache and Sid instinctively moved his foot over that way, searching for a crevice in the lava. After a long and slow climb they stopped, and Sid felt the Indian’s fingers gripping him strongly around the back of the neck. It was useless to resist. His head was being forced silently down, and the boy submitted wonderingly. Then they went forward, bent over again, and twice he felt the top of his head striking bare and jagged rock above which cut painfully. Instantly he thought of that little black mouth in the lava apron that he had caught a mere glimpse of when the Indian was turning him around. They were in that cave now, whatever it was. It was hot and suffocating in here. Sid choked for breath and sneezed as faint sulphur fumes pringled in his nostrils. He had a sense of being urged slowly upward. Now and again the fingers on his neck would press him to earth and he would go forward on hands and knees, where the least attempt to raise his head would result in a painful scratch from the tunnel roof that was evidently above them.