Sage Singer is the novel’s reclusive protagonist. Orphaned at the age of 22, she has a large scar on her face from the car accident that killed her mother. Sage, who was driving when the accident occurred, feels tremendous guilt over her involvement. She uses her job as a night-shift baker to cut herself off from society and her own family, believing that she does not deserve to be a part of a community. Sage was raised Jewish but has no connection to her faith after her parents’ deaths. Her lonely life changes when Josef Weber befriends her and then confides in her about his past. Josef’s request that Sage forgive him and then help him die draws her into his story and into a world beyond her own mind. She is forced to confront and challenge her moral beliefs and reckon with her estranged relationship to Judaism and her family.

Sage’s character arc explores the themes of forgiveness and the nature of morality. Although Sage is a good-hearted person with a sense of right and wrong, she knowingly carries on an affair with the married Adam, clinging tightly to a twisted version of love because of her nonexistent self-esteem.