A killer is cleaning up the streets of Milan by murdering those considered as deviant. An ornamental dragonfly, soaked in the blood of the victim, is left on each body.
| Directing | León Klimovsky | Director |
| Editing | Antonio Ramírez de Loaysa | Editor |
| Art | José Algueró | Set Decoration |
| Directing | Zacarías Urbiola | Assistant Director |
| Writing | Ricardo Muñoz Suay | Dialogue |
| Costume & Make-Up | Manolita Ponte | Makeup Artist |
| Writing | Paul Naschy | Story |
| Camera | Miguel Fernández Mila | Director of Photography |
| Production | José Antonio Pérez Giner | Executive Producer |
| Production | Ricardo Sanz | Executive Producer |
