Marianne Danielle, a young French schoolteacher from Paris is en route to take up a position in Transylvania, is abandoned in a village by her coach driver. At the local inn, she ignores the warnings of the locals and accepts the offer of Baroness Meinster to spend the night at her castle. At the castle, she sees the Baroness's handsome son, whom she is told is insane and kept confined (his leg is chained). When she sneaks to meet him, he says his mother usurped his rightful lands and pleads for her to help. She agrees, and steals the key to his chain from the Baroness' bedroom. Upon discovery of this, the Baroness is horrified; yet when her son appears, she obeys him and goes into the next room. Later, the servant Greta (who has taken care of the Baron since he was a baby) goes into hysterics. She forces Marianne to look at the Baroness' body, and the puncture marks in her throat. Marianne flees into the night. She is found, exhausted, by Dr. Van Helsing. She doesn't remember all that has happened, nor is she familiar when asked with the words "undead" or "vampirism." He escorts her to the school where she's to be employed.
When Van Helsing reaches the village inn, he finds there is a funeral in progress. A young girl has been found dead in the woods with wounds upon her throat. He contacts Father Stepnik, who turns out to have asked the expert on vampirism to come here. Father Stepnik has suspicions about the castle and the Baroness. That night, Baron Meinster's first victim rises from her grave, aided by Greta, as witnessed by Van Helsing and the priest. Van Helsing goes to the castle and discovers the Baroness has now risen as a vampire, full of self-loathing and guilt. After sunrise the next morning, he "releases" her with a wooden stake.
The Baron, meanwhile, visits Marianne at the school and asks her to marry him. She accepts, much to the good-natured envy of her roommate Gina. Once Gina is alone, however, Baron Meinster appears and consumes Gina's blood. When Van Helsing comes for a visit the next day, he finds the school in a small uproar over Gina's death. Van Helsing gives instructions about the body — to be kept away from the school and with people watching it until he returns. As it happens, Marianne is alone with the coffin at sunset. The locks on the coffin fall off (without unlocking), and Gina rises. She talks soothingly to a terrified Marianne, asking forgiveness for "letting him love me," and asking to kiss her. She also reveals the whereabouts of the Baron, who is hiding at the old mill.
Van Helsing discovers the body of the stablekeeper, Severin, and enters the stable just in time to see Gina escaping. Marianne doesn't want to believe the Baron is a vampire, but she does tell Van Helsing what he needs to know. The vampire hunter goes to the old mill and is confronted by both of Meinster's "Brides" as well as Greta—who, as a human, isn't repelled by the cross. Greta is killed in a fall but the cross falls into the well below the mill and is now out of Van Helsing's reach as the Baron arrives, brandishing a length of chain. In the fight that follows, the Baron bites Van Helsing and leaves him. When Van Helsing wakes, he realizes what has happened. He heats a metal tool in a brazier until it is red-hot, then cauterizes his throat wound and pours holy water on it to purify it; the wounds immediately disappear.
Italiano
Narra della sfida fra il barone Meinster e Van Helsing, cacciatore di vampiri: il primo si nasconde al secondo, che investiga sulle strane morti.