Young women in Paris are being killed and Pierre Dupin thinks he has the solution to the crimes. He and his fiancée, Camille L'Espanaye, had recently visited a carnival side show where Dr. Mirakle showed off his large ape. Mirakle has been taking women off the street to conduct experiments he hopes will prove that man evolved from apes. Mirakle takes a liking to the pretty Camille and uses his gigantic ape to kidnap her. Pierre manages with considerable difficulty to convince the police that he is telling them the truth and they set off to the Rue Morgue to stop the evil doctor and rescue his bride-to-be.
—garykmcd