The main plot involves Dr. Caligari's experiments with her patients at C.I.A (Caligari Insane Asylum) where she transfers glandular brain fluids from one patient to another. Two of her main patients, Mr. Pratt, a cannibalistic serial killer, and Mrs. Van Houten, a nymphomanical housewife, are the primary subjects of her mindswapping. Mrs. van Houten becomes the cannibal and Mr. Pratt the nymphomaniac; although, they seem to still retain some elements of themselves as well. Apparently Caligari's unconventional idea is to cure people by introducing equally opposite traits to balance out disturbed minds, but this is never implicitly stated in the film. Several other doctors, a married couple Mr & Mrs. Lodger, become concerned with Caligari's experiments and approach Mrs. Lodgers father Dr. Avol who confronts Caligari only to fall victim to her mindswapping and receives an injection of Mrs. Van Houtens fluid turning him into a transvestite nymphomaniac. Sex is a very prominent theme throughout the movie, especially for Mrs. Van Houten who appears topless and performs masturbation at several points, but there are no hard core graphic scenes as this was released as an R rated feature. By the end of the film Mrs. Van Houten has injected Dr. Caligari with her own nymphomanical fluid and herself with Caligari's ancestor's (the original Dr. Caligari from the Cabinet of Dr. Caligari)thus the patient becomes the doctor, the doctor becomes the patient and the inmates are left running the asylum.