Bud Jablonski (Jamie Foxx) is a pool cleaner with a peculiar side job: vampire hunter. As he kills an older female and an adolescent male vampire at a house where he supposedly gets hired to clean the pool, he harvests their fangs as they're worth good money.A lower-level criminal vampire named Sasha is seen being tortured by Audrey San Fernando (Karla Souza), who is also revealed to be a vampire and claims to have "big plans" with the Los Angeles area and its vampire population. The camera pans to a sign by a development project, revealing her to be a rich and powerful real estate magnate.Bud goes home to his apartment and is revealed to have financial issues as he's behind on rent. He takes a shower and picks up his daughter Paige (Zion Broadnax) from school. Although technically still married to her mother Jocelyn (Meagan Good), they do live apart from each other. Bud takes Paige to a frozen yogurt place and brings her home late.Jocelyn reveals that she's taking Paige to her mother's in Florida. Heartbroken at the thought of losing his daughter, Bud pleads with her to give him time until Monday. He hopes that selling his newly harvested vampire fangs will net him around 10,000 dollars, enough to pay for Paige's braces and other various expenses. As his lies in the past were the reason she and Bud went their separate ways, Jocelyn is very skeptical he will follow through with his promise, but she gives him a chance.Bud visits Troy (Peter Stormare), a dodgy pawn shop owner. Troy only offers him a fraction of what Bud knows he can get for the fangs at the vampire hunting organization known as "The Union", from which it is revealed Bud was expelled. Needing the money by Monday, Bud texts his old friend Big John Elliott (Snoop Dogg) in the hopes he can get him in.Audrey threatens her business partner that he may meet with the same fate as Sasha if he backs out of their deal. She also reveals she has a "product" that will allow vampires to walk in daylight. She and her henchman Klaus (Oliver Masucci) visit the house where Bud killed the two vampires. It is revealed the old woman was dear to her heart, and she swears to take revenge on whoever destroyed her.Big John meets Bud outside the Union and they meet with Ralph Seeger (Eric Lange), the curmudgeonly director who has no intention of allowing Bud back in due to his numerous prior code violations. After a great deal of convincing, Seeger allows Bud to work the day shift, which is considered second rate to the much more profitable (and dangerous) night shift.Bud and Big John head downstairs to the financial department to get payment for Bud's fangs. Cashier Seth (Dave Franco) gives him a handsome fee at first, but reduces it to a mere fraction after withholding several fees. Wanting to be promoted to his superior Carol's position, Seth is told by Seeger to partner up with Bud and report any code violations he makes in an attempt to get him out. Seth reluctantly agrees.Seth displays a great amount of theoretical knowledge about vampires, leaving Bud visibly impressed but not wanting to show it. Meanwhile, Audrey visits Troy to intimidate him, and ends up killing him.On their first mission together, Seth is told by Bud to stay in the car, but gets a call from Seeger, who tells him to get inside and verify any code violations. Horrified by the vampire slaughter, Seth wets himself and vomits outside the car. Bud, developing a soft spot for Seth, drives him home. After arriving home himself, Bud meets and welcomes Heather (Natasha Liu Bordizzo), a new tenant in his building, who claims to work as a nurse.The next day, Bud finds out Seth has been writing him up for several code violations. They go into Troy's pawn shop and find him dead with all of his teeth pulled and out on the desk. Bud then reveals he needs the money to keep his family. Seth promises not to report to Seeger.On their next mission, Bud and Seth meet with the Nazarian Brothers, famed hunters who pose as stereo repairmen. Together, they clear out a vampire nest, and the mystery product from before is revealed to be a "vampire sunscreen", allowing them to be out in the sun for fifteen to twenty minutes. Seth notices the nest contains several different types of vampires that would never choose to live together. Bud agrees he has a point, but has to run to pick up Paige from school.Having an uneasy feeling, Bud asks Paige if she'd like to stay in after they return home. Jocelyn reminds him that she's been looking forward to attending a birthday party for the past week now, and that he has to take her. Reluctanctly, he does.At the party, Bud gets a phone call from Audrey and she threatens to kidnap his wife and daughter. He gets Paige in the car as quickly as possible and immediately gets pursued by Audrey's goons. He slits one of their throats in the parking lot and gets involved in an adrenaline-pumping car chase as Paige plays with her iPad in the back seat.When Bud gets Paige back home to Jocelyn, he is ambushed by Audrey and her goons. He reveals his secret to his wife and daughter and tells them he is a vampire hunter.Bud gets knocked out and when he wakes up, it's revealed Seth was bitten and turned into a vampire. Because he cannot control his hunger, Seth lunges at Bud, who cuts his head off. Because he was turned by an "über Vampire", Seth's condition is still unstable, however, and cutting his head off doesn't kill him.As Bud heads back to his apartment complex, he goes to find Heather as she is the only person he has confided with. It turns out Heather is also a vampire turned by Audrey, and she and Bud fight briefly. Heather then reveals that the elderly vampire Bud destroyed is in fact Audrey's daughter, who wasn't turned until after she got old in "human years".Audrey and Klaus take Jocelyn and Paige to an underground temple lair. In the meantime, Heather reveals that Audrey wants to flood the Valley with vampires and facilitate them by buying property all over the area.Bud, Seth and Heather go to an abandoned shopping mall and easily dispatch of some of Audrey's goons. When they get surrounded, Big John arrives and mows down dozens of them with his mini gun.Bud and John go into the underground compound and find vampires working in a production facility for "vampire sunscreen". They dispatch of them. Meanwhile, Klaus smells Bud's presence and alerts Audrey. As Bud and John go deeper into the underground lair, they get ambushed by a pack of vampires and John gets bitten. He closes the gate behind Bud and tells him to go ahead and find his wife and child. With Bud out of sight, John empties the clip of his gun on the approaching vampires and then detonates an explosive around his belt, sacrificing himself and killing his enemies.Klaus confronts Bud, but Heather and Seth come in crashing through the roof and tell him to go ahead and find Paige and Jocelyn. They begin to fight Klaus, but he effortlessly gets the better of them in combat.Bud finds Paige and Jocelyn with Audrey and also gets bested in combat. Just as she wants to deliver the killing bite, Paige stabs her through the heart from behind with a wooden stake. It doesn't seem to phase Audrey, however, and she snaps it off. She throws both Jocelyn and Bud across the room.With Seth and Heather being held in a choke hold by Klaus, they join forces and pull his arms off, defeating him.With the wooden stake still in Audrey's heart, Bud shoots his last silver bullet at her neck in an attempt to finish her. However, she catches it between her teeth. As she runs towards Bud to finish him off, he closes his eyes, seemingly at peace with his imminent demise. However, a slicing noise reveals that Audrey has run into his wire trap, decapitating her. As her severed head mocks Bud one last time, Audrey is destroyed.After the final battle, everyone heads back upstairs where they meet a distraught Seeger. As he starts to cite union regulation in the hopes of getting Bud permanently expelled, Seth defends him by refuting all of his claims. An infuriated Seeger tells Seth he won't be getting promoted to Carol's position, but Seth tells him he's a "field man" now and will continue to fight vampires alongside Bud.Bud asks Jocelyn if he can move back into the house with her and Paige, but she only agrees to take things slow as long as Bud will only give her straight answers and stop lying. She kisses Bud on the cheek.As the camera pans to the horizon, Big John is revealed to be alive (or potentially a vampire), crawling out of a manhole.