In the early 20th century, Transylvanian vampire Count Dracula met English lawyer R. M. Renfield, who was hoping to broker a deal for some land but ended up becoming Dracula's familiar.For decades, Renfield has relied on supernatural powers that are initiated by eating bugs. Dracula has recently had a close call with some vampire hunters who almost killed him, so the duo move to New Orleans to recuperate. There, Renfield discovers a 12-step self-help group for persons in co-dependent relationships, and he plans to use the crowd there to hunt out abusive lovers whom he can kill and give to Dracula to feast on without feeling remorse. He follows a narcissistic boyfriend to a warehouse with stolen drugs, and as he batters some lower-level criminals, they are all attacked by an assassin hired by the Lobo crime family who are pushing drugs into the city.Renfield kills the assassin and attempts to hunt down the man who hired him, Teddy Lobo, but Teddy drives off in a hurry, and a weakened Renfield drags the corpses back to Dracula's lair in the basement of a dilapidated hospital. Lobo runs into a sobriety checkpoint that is run by Rebecca Quincy, a second-generation police officer who sees the opportunity to take a high-level criminal off the streets and arrests Teddy after he speeds through the checkpoint and hurls bricks of cocaine at the police. At the police station, Teddy easily gets out of custody since the feds cooperate with the Lobos. Meanwhile, Quincy has a confrontation with her sister Kate, who has also dedicated herself to police work but is gathering a large-scale case with the FBI, frustrating Rebecca, who wants answers and justice immediately.Dracula tells Renfield that the criminals he has brought as food are insufficient, and the vampire desires the blood of someone pure and innocent instead. Renfield goes to a restaurant to abduct commoners while Quincy is also led there with clues at the crime scene. The two are caught in an attack on Quincy's life that Teddy has been pressured into making so that the fierce reputation of the Lobos will be reestablished. Instead, Renfield and Quincy defend themselves, killing several gang members and leading Teddy to escape.Teddy's mother, Bellafrancesca, orders him to hunt down the man who killed her foot soldiers, and he ends up encountering Dracula when Renfield is away. The two agree to form an alliance while Renfield has taken to heart the teachings of his self-help group and decides to make a life for himself apart from his master. Setting up an apartment and changing his attitude to one of helpfulness, he gives a statement to the police to help them try to finally stop the Lobo Crime Family. Dracula learns of Renfield's betrayal and slaughters the support group members in front of his former minion.Quincy appears and finds Renfield surrounded by dead bodies, causing her to arrest him until she is immediately swarmed by police officers and the Lobos, who also want revenge on Renfield. Quincy refuses to hand him over, and she barely escapes with Renfield. Quincy wakes up the next morning to find that Renfield has saved her life, and he explains his true origin while confirming that he wants to reform himself. The two fight through a group of corrupt police officers and decide to storm the Lobos headquarters, only to find that Dracula has empowered over a half-dozen gang members to have all of Renfield's supernatural abilities, including Teddy. After a fight, Renfield kills Teddy.Quincy heads to stop Dracula and finds that her sister is beaten to near-death and only the healing properties of Dracula's blood can save her, which he will offer in exchange for Rebecca's loyalty. She tricks Dracula, leading to him having a final standoff with Renfield and Quincy that ends with the two collaborating to capture him in a magical circle.Renfield and Quincy beat Dracula into pieces, capture loads of his healing blood, and divide up the bits of his corpse into pieces of concrete that they scatter across the water system, either finally destroying the vampire or at least making it very hard for him to reform his body. Renfield later resurrects his self-help group friends with him feeling empowered to make a new life for himself.