Les Lèvres Rouges - Harry Kümel (1971)

Two days after getting married in Switzerland, Valerie and Stefan Chilton travel by train to take a boat to England to visit Stefan's mother at the Chilton Manor. However, the train must stop in Ostend and the couple lodges in the royal suite at a seaside hotel. The concierge, Pierre, advises that the place is empty since it is out of season and they become aware of three murders in Bruges. On the same night, the Hungarian Countess Elizabeth Bathory arrives in the hotel with her secretary Ilona Harczy and Pierre swears that she had been in the hotel 40 years ago with the same appearance. When Valerie and Stefan cross the mysterious countess' path, she affects their lives. Meanwhile, a retired detective snoops at the hotel suspecting that the countess is the serial killer who drains the victims' blood to use as an elixir of youth.