At Arkham Asylum, the inmates are playing a game of bingo and one of them is boasting to the Penguin of how he stashed his take and will split it 50/50 with him if they get out. The guy reveals the money is hidden in a cemetery but nothing further, but reveals he went to the Joker first, just as the Joker escapes yet again. The Penguin manages to make his own escape when they go into lockdown.
Batman gets word of the escapes as the two villains meet each other and they form a partnership to split the money – the Joker hits Penguin with a pair of electro-buzzer and he falls into the river. The Penguin recovers and sees the Batman following the Clown Prince. Batman closes in on the Joker while the Penguin gets to the cemetery first and follows the vague directions. Batman catches up to Joker for a big fight while the Penguin finds the tomb where the money supposedly is. The Penguin opens up a coffin but finds it empty and inadvertently spills some of his blood on the corpse within. He stalks off to find the money while the corpse begins to regenerate at amazing speed. Then it comes at the Penguin, who flees into the night with the creature, now a gray-skinned ghoul-like creature in hot pursuit.
The Joker plummets off a bridge and tries to get Batman to grab him while he's wielding an electro-buzzer, but Batman spots it and lets him fall. The Joker plunges into the water and the buzzer short-circuits, leaving him to sink into the waters. The creature is following the Penguin's blood when a night watchman surprises it and attacks him, biting into his neck. The Penguin flees but the creature catches up to him and animates the now-vampiric night watchman. The creature insists the Penguin act as his human guardian during the daytime and hypnotizes him when the villain proves reluctant.
Batman returns to the Batcave where he is morose over the Joker's apparent death. The vampire believes he is in Transylvania but Penguin quickly corrects him, and he relates how he was relocated to Gotham. He insists that the Penguin give him a tour so he can find some more food, and the two head out.
Bruce meets with a reporter, Vikki Vale, who is impressed that he's been there so long and starts flirting with him. However, Bruce has to leave, citing an upcoming energy expo, but he invites her as his date. Back at the manor, Bruce and Alfred overhear news reports of increased numbers of missing persons, and wonder if the Penguin is involved. As Batman prowls the city, a young woman has her purse snatched and Batman goes in pursuit. The purse-snatcher runs into the transformed night watchman, who attacks him and goes after the woman. Batman intercedes but his opponent has superhuman vampiric strength. Worse, the vampire's two victims turn into vampires and attack, forcing Batman to flee but the three leap up after him. Fighting on the train tracks, an outmatched Batman manages to pull himself away leaving them to be hit by a train, but they disappear afterward.
The original vampire, now dressed and somewhat more human, is impressed by the reports of a "Bat Man." The next morning Bruce briefs a skeptical Alfred who reminds him about Vikki Vale. That night, the Penguin awakens the vampire who is now almost entirely human, who in turn wakens his now-vast army of vampiric underlings. The head vampire sneaks into the energy expo party, where Alfred is keeping the serving staff on their toes. The vampire introduces himself to Bruce as "Dr. Alucard" and they spar verbally, and Alucard asks about the solar energy program Bruce is managing. Alucard briefly uses his hypnotism on Bruce, forcing Bruce to come with him out onto the balcony. Alfred intervenes before anything can happen, however, and Bruce connects the incident to Alucard.
Down in the wine cellar, Alucard makes one of the staff a vampire and sends him back upstairs. Alfred approaches him and notices he doesn't have a reflection in the mirror, and then the server flees. Alucard hits on Vikki and departs before Bruce can catch him, and Bruce then figures out that Alucard is…Dracula written backward. Bruce quickly puts it all together and begins to research the information in his father's medical library. Vikki gets a call and close to sunrise Bruce tunes in to find Vikki s reporting that a bat-figure has been spotted at the disappearances so Batman is the prime suspect. At the cemetery, Dracula catches the broadcast and decides to take Vikki as his bride.
Batman focuses on the cemetery since the night watchman was the first victim, while Alfred enhances his Bat-arsenal with garlic. A new watchman spots Batman at the cemetery and calls n the police, which mobilize in force. They open fire on Batman who is forced to flee through the streets and take refuge in a building, unaware that Dracula is also present and taking some of them out. Batman makes it to the roof but turns around to discover all of the policemen have been dispatched. Dracula appears behind him and appeals to him as a kindred servitude, offering to make Batman a servitor vampire. Batman is unimpressed and attacks, but Dracula is his physical superior and stays clear of the garlic-covered weapons. A rooftop chase ensues until they fight again and Dracula defeats him and prepares to eliminate the only other Bat Man in Gotham, but the sun rises and Dracula is forced to flee.
A badly injured Bruce makes it back to the Batcave where he dreams of the night his parents died, but this time he's Batman forced to witness the killing, then Batman turns into a vampire and attacks Bruce.
The Penguin goes out to prepare for Dracula's awakening the next night but the Joker shows up and enters the mausoleum and the catacombs underneath. The two fight but the Joker takes out the Penguin and finds Dracula's bier. He opens it and Dracula grabs him and feeds. Later, a vampiric Joker breaks into a blood bank and Bruce gets the Batwave signal and goes to investigate. Batman arrives and the two fight until Batman uses garlic gas bombs to drive him off. The fight continues as Batman dons a pair of electrified brass knuckles to knock him out and use as a test subject.
Back at the Batcave, an imprisoned Joker rages while Batman prepares a serum to restore him to normal. The next night Dracula's vampiric minions stalk the city as Bruce deciphers a cure from the Joker's blood and Alfred rigs up the solar generator to bombard the blood with sunlight. They don't have much luck with a cure but Alfred researches Dracula's history and comes up with the legend of Dracula's bride. Vikki arrives at the manor for their dinner date, and Bruce has Alfred make his apologies. The Joker is growing weak with hunger and is forced to feed on bugs. Vikki is disappointed at Bruce's non-appearance and there's nothing Alfred can say to console her.
Batman tries to force Joker to reveal Dracula's resting place in return for blood, but the Joker can't do so as long as he's Dracula's thrall. Bruce gives him blood, but then comes up with a cure after more research. Alfred lets Bruce know about Vikki's departure and then they feed Alfred with new blood that has the cure. The Joker goes into physical convulsions but is then restored to his normal human form. Joker has no memory of what has happened to him since he was at Gotham Cemetery, but that's enough to give Batman the location. Bruce prepares a mass dose of the cure and heads out, while Vikki misses her downtown train. Dracula appears with her and asks for her to join him…for a drink. She passes and calls Bruce for help, but Bruce can't take the call. Alfred suggests he wait until sunrise but another night may doom Gotham. Bruce tries to call Vikki back and gets no answer, and realizes that Dracula has fixated on her.
Dracula is preparing to make Vikki his new bride using the ashes of his former bride, Camilla. Batman arrives at the cemetery and enters into the catacombs, while Dracula begins the ceremony but senses Batman's presence. One of his minions attacks Batman, who injects him with the cure. The other vampires come at Batman, who has more then enough cure to go around. When they threaten to overwhelm him, Batman uses garlic gas-bombs to hold them off.
As the victims return to life and leave, Batman closes in on Dracula after subduing Penguin. Dracula uses his hypnosis against Batman, who collapses as Vikki's body decays while her essence flows into Camilla. But Bruce remembers how his parents died, and the memories let him shake off Dracula's control. Batman interrupts the ceremony and Vikki regains his life force, while a furious Dracula attacks and Batman realizes his last dose of antidote is laying spilled out on the ground. Meanwhile, Penguin has freed himself and goes after Vikki.
While Batman fights a holding battle, he sends a triangulating signal to Alfred. Vikki flees aboveground with the Penguin in pursuit. Batman leads Dracula further into the catacombs…and all the way to the Batcave. Dracula beats Batman into near unconsciousness while Alfred heads for the solar generator. At the cemetery, Vikki takes refuge in a mausoleum and Penguin stumbles across the stolen loot while pursuing her.
In the Batcave, Alfred shoots Dracula with a crossbow loaded with the antidote, but Dracula is unaffected as he is supernatural. He knocks out Alfred but Batman ascends to the upper level…where he activates the solar generator, blasting the pursuing Dracula. The vampire lord begins to disintegrate as he realizes Batman is Bruce Wayne, but it's too late – he's blasted into nothing but a skull.
At the cemetery, Penguin grabs Vicky but snaps out of it when Dracula is destroyed. He goes for the loot but the police have arrived and take him into custody. Penguin is blamed for the crimes and Batman's good name is cleared. Vicky is left to contemplate Batman and what he has done for the city…and herself.