Eade, a fourteen-year-old who has always lived on the spaceship Cradle, is on the return trip to Earth with her father. An explosion damages the ship, severely injuring him. With the ship facing imminent self-destruction, Cradle’s computer, System, takes control and refuses to perform the life-saving medical procedure her father needs. As Eade tries to override System and save her dad, she uncovers a startling truth about her origins and must confront an uncertain future, realizing her life in space isn't what she thought.