THE VAMPIRE LOVERS

In Styria, 1794, a female vampire in a diaphanous gown materialises from a misty graveyard and kills a man she lures out of a tavern. While returning to her grave, she finds her shroud missing. She is thus forced to face Baron Hartog, a vampire hunter who was stalking her in order to avenge the death of his sister. He decapitates her.

Decades later, Austrian General Spielsdorf is throwing a ball in his estate to celebrate the birthday of his niece, Laura. A countess, who has recently moved into the general's neighbouring property, is in attendance with her daughter Marcilla. After talking with a mysterious man in black, the countess tells the general she has to go visit a sick friend and asks him to care for Marcilla in her absence. Despite Marcilla's strange demeanour, Laura befriends her. Marcilla seems to be sexually attracted to her new friend. Laura starts experiencing disturbing nightmares where she is attacked by a giant cat, then dies of a gradual anemia. On her breasts, two puncture wounds are discovered. Marcilla disappears, and General Spielsdorf leaves to find Baron Hartog.

Marcilla, now going by the alias "Carmilla", is reunited with the countess. They stage a carriage breakdown near the residence of Mr Morton, a wealthy Englishman living in Styria and a friend of the general's. Once again, the countess manipulates Mr Morton into offering hospitality to her alleged relative (this time introduced as her niece). Carmilla later attempts to seduce Morton's daughter Emma, who resists her more romantic overtures. Emma also falls ill and starts suffering from nightmares of the giant cat, while her breasts show the same wounds as Laura. After Emma's father has to leave on a business trip to Vienna, Emma's governess, Mademoiselle Perrodot, is seduced by Carmilla and becomes her accomplice after sleeping with her. Meanwhile, Carmilla has started feeding on people from the nearby village, causing several mysterious deaths where the corpses are drained of all blood.

Morton's butler, Renton, learns about local vampire superstitions and enlists the help of the doctor who had already treated Laura. They use garlic flowers and crucifixes to ward Emma, who is now dying. Carmilla kills the doctor on the road. She then seduces and subjugates Renton, who was under the impression the only real vampire was Mademoiselle Perrodot. With Renton under her control, Carmilla manages to have the wards removed. Knowing she has been discovered, she dispatches Renton, with the intention of retreating into her grave and taking Emma with her as her lover.

Morton, who was called home by Renton, meets General Spielsdorf and Baron Hartog, who were on their way to the ruins of Karnstein Castle, along with Laura's fiancé Carl. Hartog reveals the Karnsteins were a family of vampires from the 16th century. In his youth, he managed to destroy nearly all of them, starting with the female vampire who had killed his sister. However, he could not find the grave of Mircalla Karnstein. Looking at her portrait in the castle hall, Spielsdorf and Morton realise she is the same girl they separately know as Marcilla and Carmilla. Carl makes haste and rides back to Morton's to rescue Emma.

As Mircalla prepares to leave with Emma, Mademoiselle Perrodot begs to be taken with her. Mircalla kills and drains her instead. Carl arrives and chases Mircalla away using a poignard as a cross. Mircalla dematerialises and flees to Karnstein Castle, where the Baron and the others await her return. Once located in her resting coffin, General Spielsdorf drives a stake into Carmilla's heart and cuts off her head, thus avenging his daughter's death. Emma is freed of the vampire's sickness and influence. Meanwhile, the image of Mircalla in her portrait on the wall turns into a fanged skeleton.

A mysterious man in black watches all these events unfold from a distance, occasionally laughing with contempt.