The film centers on Dracula's plot to convert Billy the Kid's fiancé, Betty Bentley, into his vampire bride. Dracula impersonates Bentley's deceased 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.
Eventually, the Count kidnaps Betty and takes her to an abandoned silver mine. Billy confronts the Count, but soon finds that bullets are no match for a vampire. The Count subdues the notorious outlaw and sets out to transform Betty into his vampire bride. Just then, the town sheriff and a country doctor arrive. The doctor hands Billy a silver scalpel, telling him he must drive it through the vampire's heart. Billy throws his gun at the vampire and knocks him senseless, making him easy pickings for a staking. With the Count destroyed, Betty is saved and Billy takes her away, presumably to live happily ever after.