A young American woman, Greta, takes a job as a nanny in a remote English village. When she arrives, she discovers that the 8-year-old boy she was hired to care for is actually a life-size porcelain doll that the parents treat like a real boy, as a way to cope with the death of their son. After violating a list of strict rules, disturbing events lead Greta to become increasingly convinced that the doll might actually be alive.