A wealthy playboy gathers a group of bourgeois friends at his isolated beach house for a weekend of relaxation. When bodies start pilling up, they realize they’re trapped with a killer in their midst, sending them in a frenzy to figure out who amongst them is killing the others before they are killed next.
| Editing | Mario Bava | Editor |
| Camera | Antonio Rinaldi | Director of Photography |
| Production | Luigi Alessi | Producer |
| Directing | Mario Bava | Director |
| Writing | Mario Di Nardo | Screenplay |
| Costume & Make-Up | Roberto Ranucci | Assistant Costume Designer |
| Costume & Make-Up | Orietta Melaranci | Makeup Artist |
| Camera | Emilio Varriano | Camera Operator |
| Camera | Armando Pietrangeli | Still Photographer |
| Costume & Make-Up | Giulia Mafai | Costume Design |
| Production | Ira von Fürstenberg | Executive Producer |
| Production | Pietro Bregni | Producer |
| Production | Mario Bregni | Producer |
| Camera | Mario Bava | Director of Photography |
| Writing | Mario Di Nardo | Story |
| Crew | Mario Bava | Additional Writing |
| Sound | Piero Umiliani | Original Music Composer |
| Writing | Agatha Christie | Novel |
| Production | Adolfo Martello | Assistant Production Manager |
| Directing | Mario Bianchi | Assistant Director |
| Art | Giulia Mafai | Set Dresser |
| Art | Giuseppe Aldrovandi | Production Design |
| Production | Alfonso Cucci | Assistant Production Manager |
| Art | Giulia Mafai | Set Decoration |
| Sound | Leopoldo Rosi | Sound |
| Production | Luigi Alessi | Production Manager |
