Lara (Eleanor Tomlinson) and her estranged father, Dr. Hill (Stephen Rea), travel behind the iron curtain to a decrepit castle outside the Hungarian town of Styria. In the nearby woods, Lara witnesses a violent car crash. Carmilla, (Julia Pietrucha), the lone survivor, crawls from the wreckage. When Lara hides this beautiful and mysterious stranger in the castle, the two start an intense and chaotic friendship. As their relationship deepens, crops whither, farm animals die, and the young women of Styria begin to go mad. When local girls are found dead from apparent suicides, Lara wonders if Carmilla is to blame or is there a darker secret behind the mass hysteria destroying the town.