Carmilla – Sheridan Le Fanu

"You will think me cruel, very selfish, but love is always selfish."

Laura, a lonely girl living in a castle in Styria, welcomes a mysterious guest named Carmilla, who arrives after a carriage accident. They develop an intense, passionate friendship, but Laura begins to suffer from nightmares and a wasting illness. It is revealed that the beautiful, languid Carmilla is a centuries-old vampire who preys on young women.

Predating Dracula by 25 years, this novella established the archetype of the female vampire and the lesbian subtext often found in the genre. It is a masterpiece of atmospheric, erotic horror.