Carla Pratesi, a prostitute, is killed. Her death is followed by a number of attempted murders. Carla's sister undertakes her own investigation. Police enquiries uncover a drugs trade connected to a call-girls organization but the murderer remains at large. Finally, a witness identifies the killer as a well-known actor. However, he has a strong alibi (he was shooting a film). The following night, a girl who manages to escape from the maniac's clutches swears he is a different famous actor but he turns out to have a strong alibi too! Eventually the police set a trap in the park and, with the help of Carla, kill the madman. It emerges he had been disfigured by the atomic blast at Hiroshima and went crazy because his disformed features revolted women and but them off having sex with him. He created masks reproducing the features of handsome actors just to approach prostitutes!