When an American composer and his family rent a foreboding house in England from an eccentric recluse, Mrs. Aylwood, a series of terrifying events occur, primarily to 17-year-old Jan. It turns out that the eerie experiences are connected to Mrs. Aylwood's teenage daughter's disappearance 30 years earlier. A reenactment of the disappearance unexpectedly reveals the secret of the unknown force.