Sammy Glick is the character the novel revolves around, and the mystery of his character compels the narrator, Al Manheim, to write the account that forms the novel. The central question of the book—articulated in the title and repeated as a refrain throughout the text—is how a person like Sammy comes to be: What makes Sammy run? Coming from an impoverished Jewish family in an under-resourced New York City neighborhood, Sammy becomes one of the most powerful people in Hollywood. His ability to con and manipulate people is unparalleled. His overriding character trait is a determination to rise above his present station, an urge to “run” that never leaves him.

He is completely willing to use others to achieve his goals, raising them up and throwing them under as he needs to. He does this to both Al and Julian, helping their careers when it helps his career in turn. Sammy has a strong sense of how people will behave, and he uses this intuition for his own benefit. As ruthless and unashamed as he is, he is also careful about his tricks. Al describes him as “smart enough to know that the crook who cracks his jobs too consistently is sure to be caught.