The film centers on Dracula's plot to convert Billy the Kid's fiancée, Betty Bentley, into his vampire bride. Dracula impersonates Bentley's uncle, calling himself "Mr. Underhill", and schemes to make her his vampire bride. A German immigrant couple come to work for her and warn Bentley that her "uncle" is a vampire. While Bentley does not believe them, their concerns confirm Billy's suspicions that something is not quite right with Betty's uncle.