Devil Story, also known as Il était une fois... le diable (lit. 'Once upon a time... the devil'), is a 1986 French Nazisploitation horror film written and directed by Bernard Launois. It is his seventh and last feature film. An uneven mixture of the slasher and Euro-gothic genres, it was largely condemned by critics for its incoherent script and technical incompetence. It has since gained a cult following because of its reputation as one of the worst films in history.