Peggy seeks peace after a nervous breakdown and moves with her husband Robert to a remote country house, near a boys' boarding school, where Robert will soon work as a teacher. At first, Peggy enjoys the peaceful seclusion of country life, but soon her idyll is disturbed by the appearance of a sinister one-armed man who seems to be chasing her. When Robert travels, Peggy's fear becomes reality: she is not alone in the house.