This is the film that ended the partnership between Lucio Fulci and Dardano Sacchetti. Fulci claims he came up with the story, Sacchetti wrote a treatment and they were to make it together, but it continually fell through. Eventually Sacchetti copyrighted the story himself and made the film with Lamberto Bava. Sacchetti claims that the story had been his all along and Fulci was just upset because the project never took off with him as director.