Clingman cleared his throat, asked without turning his head, "Did I tell you, Gordon, that the Tareegs' known history goes back to considerably less than a thousand years, by human time reckoning?" "Yes, you did, doctor," Troy said. It had become almost impossible for him to do work for Clingman--and Clingman invariably called on him personally when he had some mechanical chore on hand--without listening to a lengthy, rambling discourse on the scientist's latest discoveries about the Tareegs. It was an indication, he thought, that Clingman had grown increasingly hungry for human companionship of any kind. He could hardly fail to know that the majority of the station's human component was aware he had originated the suggestion made by the leading scientific group to the Hammerheads concerning the possibility of turning Cassa One into a Tareeg water world, and that he was generally despised for it. Troy's noncommittal attitude might have led him to believe that Troy either had not been informed of the fact or happened to be a man who saw nothing very objectionable in such an act. Troy was, as it happened, less certain than some of the others that Clingman and the men like Dr. Chris Dexter, who had been directing the ice-hauling operations of the _Atlas_, had come to a deliberate, cold-blooded agreement among themselves to save their own skins by offering to help the Hammerheads against mankind. It was perhaps more likely that they had acted in unthinking panic, following the gruesome executions the Hammerheads had forced them to witness. That would be more forgivable, if only slightly so. It was difficult to be sure about Clingman in any way. He might be unpardonably guilty in his own mind and still no less frightened than before--for who knew, after all, what the Tareegs ultimately intended with their prisoners? On the other hand, he might actually have buried all such considerations beneath the absorbed, objective interest he appeared to take in them. * * * * * Troy had paid no more attention than he could help at first to Clingman's scholarly monologues on his favorite theme. His own thoughts avoided the Hammerheads as far as possible. But as his personal plans began to develop and the chance that he might reach Earth grew into something more than a wildly improbable hope, he realized that the more he learned about the new enemy, the more valuable an eventual report would be. Thereafter he listened carefully, memorizing all of Clingman's speculations, and gradually developed some degree of detached interest of his own in the creatures. They had a curious history, short though it was, a history of merciless strife on twin water worlds of the same system in which any records of a common background had been long lost or destroyed. Then had come the shock of mutual discovery and renewed battling, now on an interplanetary scale, which ended in a truce of carefully guarded equality between the rival worlds.