 What is the relationship between Sattell and Pop Young?
His name was Sattell and he had reason not to talk. Pop Young alone knew the whole truth, and he kept his mouth shut, too. There is nothing like it on Earth, of course. Pop lived in it all alone, and in his spare time he worked industriously at recovering some missing portions of his life that Sattell had managed to take away from him. Sattell got the shakes when he thought of Pop, and Pop rather probably knew it. He met Sattell quite by accident. All of which happened back on Earth and a long time ago. And Sattell went into panic when he returned. Nowadays, by the Big Crack, Pop wasn't so insistent on seeing Sattell, but he was deeply concerned with the recovery of the memories that Sattell helped bring back. At such times Pop hardly thought of Sattell. He'd started to follow Sattell knowing what had happened to his wife and children, but it was hearsay only. When Sattell fled to another continent, Pop followed because he had some distinct memories of his wife—and the way he'd felt about her—and some fugitive mental images of his children. When Sattell frenziedly tried to deny knowledge of the murder in Tangier, Pop had come to remember both his children and some of the happiness of his married life. Even when Sattell—whimpering—signed up for Lunar City, Pop tracked him. If so, Sattell had profited by less than two days' pay for wiping out everything that Pop possessed. Sometimes, in the shack on the far side of the Moon, Pop Young had odd fancies about Sattell. The sun rose very, very slowly in what by convention was called the east. Near Sattell, he found memories of times when he was a young man with a young wife who loved him extravagantly. And when he was near Sattell he literally recovered them—in the sense that he came to know new things about them and had new memories of them every day. Writing-material was scarce, but he spent most of the time between two particular rocket-landings getting down on paper exactly how a child had looked while sleeping, some fifteen years before. The sun rose, and baked the abomination of desolation which was the moonscape. Sattell clearly remembered the crime Pop Young hadn't yet recalled. The Moon swung in vast circles about the Earth, and the Earth swung sedately about the Sun. But then an event occurred which bore directly upon Pop Young and Sattell and Pop Young's missing years. It didn't seem to have anything to do with Pop or with Sattell.
 Sattell is trying to escape Pop, who believes he killed his family
 Sattell uses methods to help Pop recover his memories  Sattell is trying to escape Pop, who believes he killed his family  Sattell was Pop's neighbor back on Earth  Sattell is Pop's son and the only witness who saw Pop murder his wife and other children