While walking her guard rounds in the country, Doris Lang, the daughter of a deceased werewolf hunter, is attacked by Count Magnus Lee, a 10,000-year-old, long-lost vampire lord (also known as a Noble), who intends to make her his new vampire bride.
Doris later encounters a mysterious dhampir and vampire hunter, known only as D, and hires him to protect her from Count Lee. While in town with Dan, her younger brother, and D, Doris is confronted by Greco Roman, the mayor’s son, about the Count’s attack and D, and promises to help her if he has Doris for himself. When Doris refuses, Greco reveals what happened to the entire town, including Dan. D requests that the authorities, including Greco’s father, the town sheriff and Dr. Feringo (Fehring in the English dub), should hold off Doris’ incarceration at the local asylum until he kills Count Lee.
That night, D is attacked by Rei Ginsei, Count Lee’s servant and a mutant with the ability to warp the space around his body, and Lamika, Count Lee’s daughter, who is highly prejudiced against humans and dhampirs. D holds off the attack and orders the pair to return to the Count’s castle. The next day, he travels the castle and attempts to confront the Count. Aided by the symbiote in his Left Hand, D holds his own against the Count’s monstrous minions, including Rei and his companions Gimlet, Golem and Chullah. While in the castle’s catacombs, he is ensnared and captured by the Snake Women of Midwich. Doris is then kidnapped by Rei and brought to the Count. Using his vampiric powers, D kills the Snake Women, rescues Doris before she can be killed by Lamika, and escapes the castle.