An anorexic young woman escapes from a psychiatric clinic and meets a young man who wants to help. She is caught and returned to her parents, who are soon beheaded by a garrotting stranger making the rounds about town, apparently striking only when it rains. The orphaned young woman and her new lover launch their own investigation and are endangered when a link is discovered with the victims and a particular operation performed years before..
Franco Ferrini (story), Gianni Romoli (story), Dario Argento (story), Dario Argento, T.E.D. Klein, Ruth Jessup (additional dialogue)