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 professor 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.