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.
| Actor | Role |
|---|---|
 Paul NaschyInspector Scaporella | Inspector Scaporella |
 María KostyIngrid | Ingrid |
 Erika BlancSilvana Scaporella | Silvana Scaporella |
 Ángel ArandaPietro Volpini | Pietro Volpini |
 Ricardo MerinoEdmundo | Edmundo |
 Susana MayoClaudia Volpini | Claudia Volpini |
 Eduardo CalvoProfessor Sandro Campitelli | Professor Sandro Campitelli |
 Mariano Vidal MolinaPolice Commissioner | Police Commissioner |
 José CanalejasRuggero | Ruggero |
 Ramón CenteneroVittorio Darucchi | Vittorio Darucchi |
 María VidalLucia - Prostitute victim | Lucia - Prostitute victim |
| IIngrid RabelGiulia - Secretary | Giulia - Secretary |
| FFrances O'FlynnMarie - scrubwoman | Marie - scrubwoman |
 Antonio MayansCop | Cop |
 Beni DeusNot listed | Not listed |
| CCésar VaronaNot listed | Not listed |
| AAnne MarieNot listed | Not listed |
| JJuan MadrigalNot listed | Not listed |
 Juan CazalillaNot listed | Not listed |
 Javier de RiveraNot listed | Not listed |
 Rafael AlbaicínNot listed | Not listed |
| LLuis AlonsoNot listed | Not listed |
| EErnesto VañesNot listed | Not listed |