Dario Argento's acclaimed directorial debut emerged from a successful writing career that encompassed everything from movie criticism to contributions to westerns like Five Man Army and Once Upon a Time in the West. He enlisted his father, producer Salvatore Argento, to help fund what would become a landmark in the Italian giallo genre, whose origins many link to Mario Bava's The Girl Who Knew Too Much (Evil Eye in its alternate US version). Although there are also echoes of Bava's Blood and Black Lace, much of the plot is inspired by Fredric Brown's novel The Screaming Mimi (filmed by Gerd Oswald in 1958). Coproduced with Germany's CCC Films which expected an Edgar Wallace style thriller and was put off by the level of violence. Ennio Morricone's score is disturbingly sexy.