Marcia Hunter is taken prisoner by the strange owners of a old estate when she makes a wrong turn on a stormy night. There she encounters a weird granny, brother and sister and she attempts to solve the mystery of the manor and its unusual inhabitants.

Alan Patterson (Leslie Nielsen), a successful account executive, unwittingly commits two blunders which set in motion forces that threaten to destroy his family and his career. Alan's first mistake is his innocent befriending of Lily Hanson (Natalie Trundy), a beautiful girl who lives in a world of fantasy and who has selected him as the object of her infatuation. His second mistake is calling Merle Jenkins (George Grizzard), an office boy, by the wrong name. Merle, a petty thief with psychopathic tendencies, is envious of Alan and his attractive wife, Judy (Diane Foster). Like Lily, Merle proceeds to undermine the Patterson family's happiness.