The dystopic Chicago in which Beatrice Prior lives is divided into five distinct factions. When each child turns 16, he/she must decide which group to join. It's Beatrice's turn to decide and she has to choose between remaining with her family or living her own life. During the competitive initiation process, Beatrice decides to assume a different identity and try and discover who her true friends are. When a conflict arises that could give her away, she realizes that both her loved ones and herself could be in grave danger.