A mysterious murderer has already killed seven people using the deadly venom of a snake from Martinique which causes immediate death with the victim's face turning into a horrible mask. A young and ingenious police lieutenant is called on the case
| Actor | Role |
|---|---|
 Saverio ValloneBob Rawling | Bob Rawling |
 Michela MitiBetty | Betty |
| TTony ValenteInspector Sanders | Inspector Sanders |
| MMichel ClinfordNot listed | Not listed |
| DDeborah ErgasSusan | Susan |
 Alessandra IzzoNot listed | Not listed |
 Gianfranco GalloNot listed | Not listed |
| SSacha DarwinMrs. Sanders | Mrs. Sanders |
| SSolvi StübingHarriet Anderson | Harriet Anderson |
| LLouis DekNot listed | Not listed |
 Gianni DeiHarry Francis | Harry Francis |
| LLara OrfeiNot listed | Not listed |
 Laura TroschelMirta Francis | Mirta Francis |
 George ArdissonChief of Police (as Giorgio Ardisson) | Chief of Police (as Giorgio Ardisson) |
 Giovanna LenziJulie Garrett (as Jeannette Len) | Julie Garrett (as Jeannette Len) |
 Linda ChristianThe Narrator | The Narrator |
| SSimonetta GalleseNot listed | Not listed |
| VVittorio ForteNot listed | Not listed |
| AAlessandro CroceNot listed | Not listed |
| GGiovanni NardoniNot listed | Not listed |
| EEmy ValentinoNot listed | Not listed |