"Our life is harsh," the talkative patriarch told the explorer between lessons. "Game is scarce and there is little vegetation. Once we grew crops, but now the soil is sterile and bears little, but for wild vegetables and fruits in those isolated places where the ground is yet fertile. This is a world of rock, my son. No creature of flesh and bone was meant to trod here." The man spoke truth. All about, the valley lay barren, the sandy soil smothered under by tons of rock. Gene thought it a marvel that the tribesmen were able to exist at all in such a place. They must have great courage to fight such a hopeless battle against the forces of nature. On his fifth day in the cave city, Gene was summoned to the dwelling of Old One, the tribal chief. There, too, was the gray-eyed giant whom Gene had first met the day of his arrival. Old One raised a withered hand to signify peace, and the biologist solemnly did likewise. The venerable man nodded approval and settled back on his fur-covered stone bench. "It stuns my senses," he murmured. "Kac, say again this youth was spawned of a beast that walks through air." "Truly, he was, Father," the dark-haired man said gravely. "The Beast People were besetting him and bearing him under at the time our hunting party came upon the scene. The spineless creatures fled at mere sight of our warriors, though there was a far greater number of them than our small party could boast. The beast that walked through air still rests where it fell from the sky. I fear it is dead, for no longer does it give out its breath of fire." "Not dead, but sleeping," Gene said, wisely refraining from burdening the simple minds of these people with scientific principles. He noticed that many tribes-people were silently drifting into the cavern, curious to see this strange being who was so like themselves, yet so different. "Now, Old One," he addressed the chief in a respectful tone, "I know so little of your world. I am as an old woman in a strange cave; lost. Tell me of the Beast People. How do they see--for they have no eyes--and how is it there is so much animosity between your races? Perhaps, if their sin is great enough, I will help you against them." Old One frowned and thoughtfully fingered his dingy gray beard. "Nothing can be done about the Beast People. Long ago, they came from a world beyond worlds. At the coming of our ancestors, the two races took up a constant war for possession of this cave city. "The legend is that they, too, were spawned of a great beast that walked through air. Their air-beast, just as yours, fell from the sky with a great crash. But this sky-monster slept the sleep of no awakening, and for them there was no returning.