Saul shook his head. "I don't like it. But--" He hesitated, scowling thoughtfully. "All right. We'll settle it up in the cave. Let's move." He said to Trevor, "You go in the middle of us. And if you try to signal anyone...." "Who the devil would I signal to?" retorted Trevor angrily. "Listen, I'm sorry I ever got into your bloody valley." But he was not sorry. Not quite. His senses were on the alert to mark every twist and turn of the way they went, the way that would bring him back to the sun-stone. The ravine narrowed and widened and twisted, but there was only one negotiable path, and that was beside the stream bed. This went on for some distance, and then the ravine split on a tremendous cliff of bare rock that tilted up and back as though arrested in the act of falling over. The stream flowed from the left-hand fork. Saul took the other one. They kept close watch on Trevor as he slipped and clambered and sprawled along with them. The detritus of the primeval cataclysm that had shaped this crack in the mountains lay where it had fallen, growing rougher and more dangerous with every eroding storm and cracking frost. Above him, on both sides, the mountain tops went up and still up, beyond the shallow atmosphere. Their half-seen summits leaned and quivered like things glimpsed from under water, lit like torches by the naked blaze of the sun. There were ledges, lower down. Trevor saw men crouched upon them, among heaps of piled stones. They shouted, and Saul answered them. In this narrow throat no man could get through alive if they chose to stop him. After a while they left the floor of the ravine and climbed a path, partly natural and partly so roughly hewn that it seemed natural. It angled steeply up the cliff face, and at its end was a narrow hole. Saul led the way through it. In single file the others followed, and Trevor heard Jen's voice echoing in some great hollow space beyond, calling Hugh. There was a cave inside, a very large cave with dim nooks and crannies around its edges. Shafts of sunlight pierced it here and there from cracks in the cliff face high above, and far at the back of it, where the floor tipped sharply down, a flame burned. Trevor had seen flames like that before on Mercury, where volcanic gases blowing up through a fissure had ignited from some chance spark. It was impressive, a small bluish column twisting upward into rock-curtained distance and roaring evilly. He could feel the air rush past him as the burning pillar sucked it in. There were people in the cave. Less than a hundred, Trevor thought, not counting a handful of children and striplings. Less than a third of those were women. They all bore the same unmistakable stamp. Hard as life must be for them in the cave, it had been harder before. He felt his legs buckling under him with sheer weariness. He stood groggily with his back against the rough cave wall.