Eight-year-old Ona has lost just about everything: her home, her possessions, her mother, and almost her life. When she and her father move into her Baba’s apartment complex after these traumatic events, they had hoped for a clean start. But a mysterious specter follows her, and Ona befriends the ghost she discovers haunting the boiler room. When her new friendship starts allowing her to see other ghosts—the ghosts who haunt the other residents of her building—she decides to use her ability to help her new neighbors face their troubles and free themselves from their specters. In doing so, however, Ona must eventually come face to face with a much darker foe—her own trauma and grief.