It’s telling that as Stone describes Quan and this other boy, she refers to them both as
boys. The other boy might be older and in trouble—but he’s still a boy, not an adult man. With this, she reminds readers that most of the novel’s characters are children and should be treated as such. They may be involved in illicit activities (like the deal that seems to have happened in the rocket ship), but the fact that this happens in the rocket ship at all—at a children’s playground—drives home their youth.