After witnessing a man's death in a bizarre accident, Father Pergado goes on a spiritual retreat, where he encounters his alien double bent on world conquest.
In the Nineteenth Century, in London, the psychologist Charles Marlowe researches a new drug capable to release inhibitions and uses his patients as guinea pigs. He discusses the principles of Freud with his friend Dr. Lanyon and decides to experiment his drug in himself. He becomes the ugly and evil Edward Blake and his friend and lawyer Frederik Utterson believes Blake is another person that might be blackmailing Charles. Meanwhile Charles loses control of his transformation.
The Theatre of Death in Paris specializes in horror presentations. A police surgeon finds himself becoming involved in the place through his attraction to one of the performers. When bloodless bodies start showing up all over town, he realizes there could be links with the theatre.
After the original owner dies in a mental asylum, a man moves into an abandoned mansion with a sordid history. Meanwhile, a few locals conspire to steal a large amount of money, said to be hidden somewhere on the premises.