Delphine Seyrig plays Countess Báthory, who arrives at a hotel in Ostend—off-season—and takes an interest in a couple of young honeymooners, eventually regaling them with the story of her ancestress, who preserved her youthful beauty by bathing in virgin blood. With gorgeous production design, dazzling costumes, and a haunting score by François de Roubaix, Harry Kümel’s “fairy tale for adults,” as he called it, is one of the most elegant iterations of the vampire genre.