It is based on the J. Sheridan Le Fanu novella Carmilla .
Is part of the so - called Karnstein Trilogy of films , the other films being Lust for a Vampire ( 1971 ) and Twins of Evil ( 1972 ) .
It is based on the J. Sheridan Le Fanu novella Carmilla and is part of the so - called Karnstein Trilogy of films , the other films being Lust for a Vampire ( 1971 ) and Twins of Evil ( 1972 ) .