Cast: Tony Musante, Suzy Kendall, Enrico Maria Salerno, Eva Renzi, Umberto Raho, Renato Romano, Giuseppe Castellano, Mario Adorf, Pino Patti. Screenplay: Dario Argento, based on a novel by Fredric Brown. Cinematography: Vittorio Storaro. Production design: Dario Micheli, Film editing: Franco Fraticelli. Music: Ennio Morricone.