

Police Comissioner Datti is investigating the murder of a female doctor whose murderer seems to be a thirty-fivish year old man. Soon another murder follows: Pianist Robert Dominici's girlfriend is found killed. The killer also challenges Datti on the phone and says he can't be caught since he has a secret which makes him invulnerable. In the meantime the clues seems to point in strange directions...
Ruggero Deodato
Gloria Datti

Carola Stagnaro
Dr. Carla Pesenti
Daniele Brado
Dr. Vanni

Caterina Boratto
Robert's Mother
Lewis E. Ciannelli
Chief Physician
Renata Dal Pozzo
Agent Corsi