A hard-working, blue-collar dad just wants to provide a good life for his quick-witted 10-year-old daughter. His mundane San Fernando Valley pool cleaning job is a front for his real source of income: hunting and killing vampires.
Bud Jablonski (Jamie Foxx) works as a pool cleaner and after seeing a man on the nearby house leaves, Bud silently breaks in and was confronted by two vampires living there - an elderly woman and a younger man. After a lengthy fight, he kills the vampires and extracts their teeth.It is revealed that Bud is actual job is a vampire hunter where he takes off the fangs of the vampires he killed to be sold for a paycheck with fangs from older vampires, called "Elders", command a higher pay-out.
Bud tries to sell the teeth to Troy (Peter Stormare) at the pawnshop, but the prices offered are low and does not help him with his money troubles. The union pays higher, but Bud is working without a permit and hence has to approach Troy and the black market, which doesn't pay as much. He can only get $2800 for the fangs of the 2 vampires he killed.
Bud badly needs the money as his ex-wife Jocelyn (Meagan Good) is planning to move to Florida (to live with her mother) with his daughter Paige (Zion Broadnax) as her private school fees are too high ($5000). To pay the school bills, and also to fund braces ($4800) for his daughter (Bud has exactly 7 days to come up with the money), Bud is forced to go back to the vampire hunting union. He had been kicked out off because of his risky and aggressive hunting style that contravened many of the union's protocols.
With the help of his friend John Elliot (Snoop Dogg) who is well respected within the union & its chief Ralph Seeger (Eric Lange), Bud gets another chance at the union, under strict conditions. In his previous stint, Bud was reckless, would endanger civilians and would conduct attacks on vampires in vicinity of innocent humans. He also endangered a fellow union members life.He is forced to only work the day shift which does not pay as much and he must also be baby-sat by a union rep Seth (Dave Franco), who is tasked to look for any violations committed by Bud and report them. Seth doesn't want to be in the field, but Seeger offers him a promotion, if Seth can report a violation on Bud. Bud sells his fangs at the Union, but had to pay $5000 as joining fee, 15% commission and 50% deposit till he submits his paperwork.
Meanwhile, a female vampire, Audrey (Karla Souza) finds the vampires that Bud killed and mourns the death of the old vampire. Audrey has figured out a way to survive in sunlight, by staying in the shades. In her search for Bud, she finds the pawnshop owner; she tortures, interrogates, and kills him. She reveals that humans used to worship vampires as gods before the humans turned on them and that she has plans to recreate that old "god worship" hierarchy.
Seth is a complete novice in the field. He knows all theory but is useless in a crisis. Juvie vamps are new vamps who are converted by an existing vampire. They can't process human blood yet and survive by drinking animal blood instead. There are 5 species of vamps, Southern, Eastern, Spider, Uber and Juvie. They are organized by age, and sunlight is the only thing they are scared of. They can't reproduce, but they can turn people. Bud decides to go after Juvies, even though they pay less, as he is out of time.
Meanwhile, Bud goes around killing vampires with Seth to earn the money he needs. Seth has to be with Bud all the time and inevitably, he is attacked by vamps. Seth urinates on himself and vomits after his first encounter. Bud gives him a special powder to wash himself with, as when a vampire dies, it releases a chemical that other vampires can sniff and track down their killer. Bud lives next door to Heather and is friends with her. She is a nurse.
Despite violating several protocols (when Bud finds Troy's body, as per protocol he has to report civilian death to the union. But he skips it as it will place him under a 30-day suspension and he does not have 30 days), Seth does not report Bud after learning of his aim to support his family with his earnings. After Bud (with Mike Nazarian (Steve Howey) & Diran Nazarian (Scott Adkins)) finds and destroys an unusual nest of vampires due to their sheer numbers and the different types living together, Audrey contacts Bud (she is able to track him down as Heather's boyfriend is a vampire and he "smelled" Bud when he returned to his apartment earlier. Heather is also a vampire) threatening his family, revealing the old vampire was her daughter.
Bud rushes to his ex-wife to save her while being pursued by vampires. He fails to get there in time and his family is taken hostage and Seth gets transformed into a vampire. Seth gets hungry and attacks Bud, but Bud cuts off his head. Seth is somehow not killed and decides to help Bud. Bud now has to rescue his family and stop Audrey's plans. Bud confronts Heather, who says she hates working for Audrey, but has no choice. She also tells Bud that the Vampire he killed earlier in the week is Audrey's daughter.
Seth and Heather (Natasha Liu Bordizzo) help Bud attack Audrey's stronghold and they are joined by John. In Audrey's lair, they find a factory that produces a sunscreen that allows vampires to survive in the daylight, allowing them to take over the entire Silicon Valley.Midway through the fight, John gets bitten and eventually sacrifices himself so Bud can go on ahead to save his family. Bud is no match for Audrey but manages to trick her during the fight (He expends his last bullet on Audrey, prompting her to charge him. But she ends up severing her neck, as Bud has installed a silver wire in the path at head height) and saves his family.
Later, Seth helps Bud stay in the union by citing protocol to justify his actions. As the Jablonski family drives away, John climbs out of a sewer manhole showing that he survived the fight.
