Jack, married to Elizabeth, is a photographer and artist and one of the two protagonists of the novel. As a college student, he is quiet and awkward, not socially outgoing or noticeable. When he meets Elizabeth, she is drawn to this quiet and reserved aspect of Jack, seeing him as introspective and thoughtful without the traditionally dominating masculinity she dislikes.

Jack is highly shaped by a childhood in which he quickly gleaned that he was unwanted. His mother saw his premature birth as a sign that Jack was sickly—an idea that became self-fulfilling prophecy when Jack internalized the message that he was weak and incapable. He grew up feeling isolated and emotionally alone in his rural town, unable to relate to his machismo-oriented peers or to his parents. He was inspired to pursue art by his much older sister, Evelyn, a painter who served as a model for Jack, as she left their small town and traveled the country. Idolatry of Evelyn convinced Jack to go to Chicago at 18 and to seek out a bohemian lifestyle that focuses on intellectual and artistic pursuits while criticizing the established mainstream—the antithesis of his previous life.

Jack is highly concerned about his seemingly fading marriage to Elizabeth.