Daughters of Darkness (in France, Les Lèvres rouges, and in Belgium, Le Rouge aux lèvres, both literally translated as The Red Lips) is a 1971 Belgian horror film (with dialogue in English), directed by Harry Kümel. It is an erotic vampire film, following a style Camille Paglia calls psychological high Gothic.
A recently married young couple, Stefan (John Karlen) and Valerie (Danielle Ouimet), are on their honeymoon. They check into a grand hotel on the Ostend seafront in Belgium, intending to catch the cross-channel ferry to England, though Stefan seems oddly unenthused at the prospect of introducing his new bride to his mother. It is off-season, so the couple are alone in the hotel. Alone, that is, until the sun sets and a mysterious Hungarian countess, Elizabeth Báthory (Delphine Seyrig) arrives in a vintage Bristol driven by her ‘secretary’ Ilona (Andrea Rau). The middle-aged concierge at the hotel swears that he saw the Countess at the same hotel when he was a little boy. The countess quickly becomes obsessed with the newlyweds, and the resulting interaction of the four people leads to sadism and murder. Ilona, Stefan, then the Countess all die, leaving Valerie, now transformed into a creature similar to the Countess, stalking new victims.