The Brides of Dracula
Marianne Danielle, a young French teacher traveling to take up a position, finds herself stranded overnight in rural Transylvania. She accepts the hospitality of the mysterious Baroness Meinster at her remote castle, only to discover a chained young man within the castle grounds and learn from the Baroness that he is her son, mentally deranged. Pitying him, Marianne steals the key and releases him, unknowingly freeing Baron Meinster, a vampire. The Baroness, having kept her son imprisoned to prevent his evil, is killed by him, and he soon begins to prey on the local village girls. Dr. Van Helsing arrives in the area investigating the unusual deaths and realizes a vampire is at work. He soon uncovers Meinster's identity and his growing influence, including turning a village midwife and later Marianne herself into his vampire servants. Van Helsing battles Meinster, eventually defeating him by exposing him to sunlight, which turns him to dust, and then cures Marianne of her vampirism.