Upon the death of Mamaloi, her foster daughter Lisa Fortier and the voodoo clan learn that their leader did not name a successor. The Mamaloi’s son Willis is infuriated at the assumption that Lisa, a voodoo priestess herself, will be favored to take over, and bitterly insults her, prompting Lisa’s fiancé, ex-police detective Justin Carter, to threaten him. Now determined to seek revenge against Lisa and the clan, Willis enlists Ragman, a disgruntled, deposed Papaloi, who gives him a bag of bones and an incantation to awaken a curse that he promises will avenge them both. That night at a mansion he is house-sitting, Willis sheds dove’s blood and recites the incantation over the bones, which ignite and turn to ash. Although Willis believes he has failed, Lisa senses from afar that another’s soul has been reawakened by fire. Back at the mansion, the unwitting Willis is attacked by Blacula, a menacing vampire of commanding stature who has been awakened by Willis’ incantation. Soon after, Willis, now a vampire slave, is frustrated that he cannot view his dapper appearance in a mirror because a vampire casts no reflection, as he dresses for a party at Justin’s. Forbidding Willis from leaving the house, Blacula threatens to kill him if Willis does not obey his every command. Powerless to control his own blood thirst and rage, Blacula remembers the moment that lead to his tragic destiny: In the 1700s, when African prince Mamuwalde and his wife Luva ask Count Dracula at his Transylvanian castle to sign a petition abolishing slavery, the white man scoffs at the black couple and condemns Mamuwalde to eternal life as a vampire by biting him and entombing him in a coffin, thus turning him into Blacula. Back in the present, Willis’ friends Elaine and Louis arrive at the mansion to pick him up for the party but instead become Blacula’s and Willis’ next victims. Later at the party, Blacula, who introduces himself as Mamuwalde, entrances all the women with his mysterious appearance and impresses Justin and Lisa with his knowledge of African artifacts, which Justin collects. As Lisa shows him around the house, Blacula asks her if she can change the destiny of a soul as some of the party guests have suggested. Blacula’s thoughts are suddenly diverted upon seeing Lisa’s friend Gloria cut her hand. Soon after, Blacula finds Gloria resting upstairs and bites the horrified woman, who stumbles downstairs and dies in front of the party guests. Meanwhile, Blacula transforms into a bat and flies to a prostitution district, where he returns to human form and is accosted by two pimps demanding money. Angered that the men have made “slaves” of their black sisters, Blacula feeds on their blood until they die. Later that night during a police investigation, Sheriff Dunlop learns that all three of the recent murder victims have snake-like puncture marks and are drained of blood. Suspecting the voodoo clan, he enlists his old co-worker Justin to interview Lisa, who claims that Willis is the only person in the clan who holds a vendetta, but only against her. Days later, Willis’ girl friend Denny comes to the mansion looking for him, and as Willis seductively massages her back, he bites her, turning her into another vampire slave. Meanwhile, Lisa is watching over Gloria’s body when the deathly pale corpse grabs her neck to bite her, but Blacula arrives just in time to order his slave to leave. Although frightened by Blacula’s ominous powers, Lisa agrees to help release him from the curse. After the discovery of bat fur at a crime scene, Justin immerses himself in occult book research and becomes convinced that a vampire is responsible for the murders. Dunlop scoffs at the idea, until noticing that crime scene photographs are strangely missing images of the victims’ bodies, another vampire phenomenon. Meeting Blacula to show him his African jewelry, Justin vows to kill the creature responsible for the murders, but Blacula warns that Justin will die before he can outwit a vampire. Later that night at Lisa’s apartment, Blacula begs her to exorcise the demonic plague in his body. When two of Dunlop’s policemen arrive at the apartment to serve her with a warrant, Blacula subdues the men and takes Lisa to the mansion, where she begins her ritual, chanting over a lock of Blacula’s hair and a voodoo doll resembling him. Learning of Blacula’s location, Dunlop, Justin and several officers race to the mansion. Although Justin has armed them with wooden stakes to kill the vampires, the disbelieving policemen fall easy prey to the hungry vampires inside. Justin and Dunlop narrowly escape death several times by stabbing the vampire slaves with stakes. Having broken his last stake, Justin grabs a bow and arrows and shoots Willis repeatedly, until one of the arrows makes its mark. A fiendish Denny turns on Justin, but recognizing her beneath the gruesome death mask, Justin is unable to kill her. An officer then drives a stake through her heart before she can cause more harm. Meanwhile, Blacula can feel the curse lifting as Lisa falls deeper and deeper into a voodoo trance, but the rite is cut short when Justin bursts into the room. His escape from the vampire curse thwarted, Blacula chokes Justin, but Lisa promises to try again if Blacula will release her lover. Blacula tosses Justin aside and forces Lisa into the hallway, where he kills several police officers and attacks Dunlop. Seeing Blacula’s hideous transformation, Lisa realizes her life is in peril. Justin rushes to her aide with his one remaining arrow but drops it when Blacula attacks him. Lisa takes the arrow and stabs the vampire voodoo doll repeatedly until Blacula staggers, collapses and dies from the wounds Lisa has inflicted.