The story takes place 12000 years in the distant future, a future where nuclear war took place, and from the ashes of the Earths remains vampires emerged as a dominant race. Taking the title of Nobles, they enslaved the remnants of humanity and ruled over them with the aid of special magical technology and a race of inhuman creatures. But over time, they slipped into decadence and decau and humanity won their freedom.
The film begins with a young maiden, Charlotte Elbourne, being abducted by the Noble Meier Link. Her family calls upon two famous bounty hunters to get her back (preferably alive, but dead if shes been changed into a vampire). One is the Marcus Brothers, the most brutal family of bounty hunters. The other is D, a dhampir (a half-human half-vampire being) who has taken to hunting vampires, who keeps a magical talking parasite in his left hand and bears a stoic demeanor.
D meets the Marcus Brothers: the brutal leader Borgoff, the knife-wielding Kyle, the hulking hammer-swinger Nolt, the psychic Grove (though his abilities have left him mortally weak) and their adopted stepsister Leila. While the Marcuses have a head start, Ds Left Hand is able to magically track down Meier to a resting house (however, Borgoff schemes to let D do all the work and get the girl from him afterwards). Meiers carriage sets off with Charlotte inside; D fights Meier but halts when Charlotte calls out to Meier. Leila appears close behind but is injured in the fight; D tends to her wound, and in disgust she snarls at him.
Meiers carriage is tracked to the Barbarois, a community of monstrous beings that have served vampires since time immemorial. D enters, and discovers that three guardians have been paid to guard Meier: a shadow-being called Benge, a werewolf named Mashira and a woman named Charlotte who can use her hair like tentacles and absorb elements. Benge uses his ability to surreptitiously kill Nolt, but he manages to warn his brothers before dying; consequently Grove uses his psyche to enter Barbarois and annihilate as many Barbarois as possible. Meiers carriage leaves Barbarois and a pursuing D strikes down Groves spirit, but Benge uses his power to temporarily trap D inside a shadow.
The Marcus brothers take off after the carriage, but soon their tank is incapacitated by Caroline. Benge stays behind to deal with them, but thanks to Nolts final warning they are able to kill him. But they still need to get fuel for their tank, so Kyle and Leila head to a nearby town. They find D is also in town, so Leila turns the townsfolk against him to get him out of their hair. But one of them unexpectedly stands up with a gun to defend D, saying D saved his life as a child and hes returning the favour.
At a stop, Charlotte steps out to enjoy the sunlight. D meets her and questions her. He learns that shes in love with Meier, and that shed rather die than return home. This revelation disgusts and enrages Leila, who swiftly captures her; however Mashira and Caroline were keeping watch nearby, and attack. Mashira gets Charlotte away, while Caroline engages D and Leila. D manages to stop Caroline temporarily before he is overcome by heat syndrome (as a half-human half-vampire he can endure the sunlight, but every now and then it gets too strong and he must bury himself for a time). Leila helps him bury himself in return for having assisted her, but has to deal with a regenerated Caroline. Fortunately a storm begins, and a lightning bolt strikes Caroline and electrocutes her, ending her permanently.
During the storm, Leila has to seek shelter in the same place as D. Although she is harsh towards him, the rain eventually softens her. She shares a bit of her past: her father was killed trying to rescue her mother from being abducted by a vampire, who was turned (and later stoned to death by members of her own village). Filled with rage towards all vampires, she joined the Marcus Brothers to kill them all; shes resigned to this as the only life she will ever have. D, as a dhampir, is a kindhearted soul who is resigned to never having a normal humans life; but he reminds Leila that his fate is sealed, unlike hers. They both make a pact, that whichever of them dies first will have the other put flowers on their grave. As the rain stops, they go back to business rivalry and take off on their separate ways.
Borgoff and Kyle work out that Meier is headed for the Castle of Chaythe, a fearsome place avoided by humans and vampires alike. However, to get there the carriage has to cross a bridge, which is where they set up an ambush: they place bombs under the bridge and with this force the carriage to a stop. Mashira seemingly bails out, leaving Meier and Charlotte unprotected. Kyle forces her out, but Meier steps out into the sunlight to save her, burning himself terribly. Charlotte breaks free and runs to save Meier, to the surprise of Borgoff and Kyle (and Leila, who witnesses the bridge from afar); the two of them decide to just let Charlotte die and then kill Meier, since they get paid for her return either dead or alive. But before they do anything, Mashira kills Kyle and cuts out Borgoffs eye; hed gotten away to remove the bombs from underneath the bridge.
The surviving Marcuses and D continue the pursuit of Meier and Charlotte, though now its for personal reasons: Borgoff and Leila want to avenge their fallen brethren, and D wants to prevent the possible conception of another dhampir. Mashira stays behind to stall D, and Meier and Charlotte finally reach the Castle. There they greet Carmilla, and their purpose is revealed: aeons ago vampires used to travel into space in rocket ships, to distant worlds. Meier and Charlotte desire this ship to head to the legendary City of Night and Stars, where they can be together without resistance from anyone.
However, Carmilla has her own plans. She creates an illusion of D and Charlotte to slice Meiers head in half, a mirage of Nolt and Kyle to trick Borgoff into becoming her vampire servant, a hallucination of a newly-orphaned Leila to throw her off track, and a vision of Meier to lure Charlotte to her tomb to feast on her blood. Borgoff attacks Leila and D, but Grove uses up his last strength to use his spirit to destroy Borgoff. D, unfazed by whatever apparitions Carmilla shows him, makes his way into her tomb, where she has drank enough blood to take on a corporeal body. She causes Ds vampire instincts to surface and he is almost overcome, but Meier puts himself back together in time for the two to team up, and eventually Carmillas body is destroyed and her spirit swallowed by Left Hand.
However, it is too late for Charlotte, who was drained of blood beyond recovery. She and Meier have one last moment of love before she passes away. Meier decides to carry on his journey with Charlotte by his side, but D proposes to take her body back to her family. The two fight, but eventually D settles for taking Charlottes ring as proof of her death. Meier and Charlotte leave in the rocket ship, with D and Leila watching. Leila has been inspired by the dream the two lovers had: having lost her family a second time and seeing that vampires can love just as humans can, she decides to start a new life, a life away from hatred and vengeance.
The film ends many decades later, as a family holds a funeral for their beloved matriarch Leila. Her granddaughter sees D watching from a distance, and comes to invite him home (times have changed since, as vampires or at least only D are held in better regard). He declines, saying he only came to keep a pact with an old friend, but says hes glad she was able to make a life and family for herself. He gives the girl a thankful smile, before he rides away...