THE FRENCH SEX MURDERS

A petty criminal named Antoine (Peter Martell) is blamed for the murder of a prostitute who was killed at Madame Collette's exclusive whorehouse in Paris. He is sentenced to death by guillotine, and he swears revenge on everyone who helped convict him. At the last moment, he manages to escape from the prison – but is then decapitated in a motorcycle accident. A scientist Prof. Waldemar obtains the criminal's severed head from the morgue for purposes of experimentation. The judge, who sentenced Antoine to death later turns up murdered, and then one by one, the prostitutes at Madame Collette's begin turning up murdered as well. Everyone believes that Antoine is causing the murders to happen, and that he is wreaking vengeance from beyond the grave.

The film concludes with the revelation that the murders were believed to be caused by Antoine's revenge from beyond the grave, following his decapitation and the subsequent killings among those connected to his trial.

The ending ties the string of murders back to the initial injustice and Antoine's vow, playing ambiguously with supernatural overtones. By suggesting the killer's identity is linked to the supposed vengeful spirit, the film leans into giallo tradition, where the line between rational crime and supernatural retribution is blurred for maximum effect.