In this passage, Grandpa is so moved by Billy’s hard work and steadfast nature that he begins to cry. He sees how hard Billy has worked for these dogs and he is deeply moved—yet his instinct is to conceal his emotions, however halfheartedly, from his grandson. Billy’s relationship to emotion is very different from his grandfather’s, and over the course of the novel, both men will continue to learn about the nuance of emotional expression from each other.