Megan, a young teacher hired to care for Estelle, a six-year-old girl who has become mute after witnessing her father's murder in London, now lives with her grandparents in Cornwall. Estelle's mother, unable to cope with the loss of her beloved husband, is now in a mental institution. The police are afraid that the murderer, believing he had murdered the little girl along with her father, are fearful that if he discovers she is still alive, he may try to harm her, so they suggest that her whereabouts are kept secret. Agreeing to look after the little girl has consequences for Megan; some are happy, while others are full of danger.