When he had finished with his arm and the prowler had lessened the bleeding of its shoulder it took a step back toward the ridge. He stood up, knowing it was going to leave. "I suppose the score is even now," he said to it, "and we'll never see each other again. So good hunting--and thanks." It made a sound in its throat; a queer sound that was neither bark nor growl, and he had the feeling it was trying to tell him something. Then it turned and was gone like a black shadow across the grass and he was alone again. He picked up his knife and bow and began the long, painful journey back to the caves, looking again and again at the ridge behind him and thinking: _They have a code of ethics. They fight for their survival--but they pay their debts._ Ragnarok was big enough for both men and prowlers. They could live together in friendship as men and dogs of Earth lived together. It might take a long time to win the trust of the prowlers but surely it could be done. He came to the rocky trail that led to the caves and there he took a last look at the ridge behind him; feeling a poignant sense of loss and wondering if he would ever see the prowler again or ever again know the strange, wild companionship he had known that day. Perhaps he never would ... but the time would come on Ragnarok when children would play in the grass with prowler pups and the time would come when men and prowlers, side by side, would face the Gerns. * * * * * In the year that followed there were two incidents when a prowler had the opportunity to kill a hunter on prowler territory and did not do so. There was no way of knowing if the prowler in each case had been the one he had saved from the cloudburst or if the prowlers, as a whole, were respecting what a human had done for one of them. Schroeder thought of again trying to capture prowler pups--very young ones--and decided it would be a stupid plan. Such an act would destroy all that had been done toward winning the trust of the prowlers. It would be better to wait, even though time was growing short, and find some other way. The fall of one hundred and sixty-three came and the suns were noticeably moving south. That was the fall that his third child, a girl, was born. She was named Julia, after the Julia of long ago, and she was of the last generation that would be born in the caves. Plans were already under way to build a town in the valley a mile from the caves. The unicorn-proof stockade wall that would enclose it was already under construction, being made of stone blocks. The houses would be of diamond-sawed stone, thick-walled, with dead-air spaces between the double walls to insulate against heat and cold. Tall, wide canopies of lance tree poles and the palm-like medusabush leaves would be built over all the houses to supply additional shade.