The story follows 18-year-old Madeline Whittier, a half Japanese, half African-American 18-year-old who is being treated by her doctor mother for severe combined immunodeficiency (SCID), and therefore is not allowed to leave her house or interact with anything that has not been "sanitized". Her world consists of her mother Pauline, her nurse Carla, and the books she finds comfort in; with her father and brother having died a long time ago in a car accident.