 What effect does Sattell's proximity have on Pop?
Sattell got the shakes when he thought of Pop, and Pop rather probably knew it. 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. The sun rose very, very slowly in what by convention was called the east. 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.
 It restores Pop's memories of his wife and children
 It brings Pop's memory of the murder of his family into clarity  It motivates him to plot his revenge against his family's murderer  It amplifies the pain of his Pop's head injury  It restores Pop's memories of his wife and children