Jimmy Mathew Horne and Fletch James Corden are two friends living in London, each carrying his own heavy cloud of life: Jimmy is dumped by his unscrupulous girlfriend Judi Lucy Gaskell, and Fletch is fired from his job as a clown after an ill-judged punch. In an attempt to escape their troubles, they set their sights on a remote village in Norfolk that somehow appears on an old map, offering a chance to press pause on their messy days and start anew. As they reach a windswept pub on the village fringe, Jimmy’s mood darkens—partly because Fletch has smashed his phone—yet they glimpse a striking scene: a string of foreign history students leaving the premises.
Inside, they are met by a morose crowd of locals and a seemingly deranged vicar Paul McGann who believes Jimmy might be a long-lost descendant of a local vampire slayer. The students are heading to a cottage for the night, and Jimmy and Fletch soon follow the van to catch up as its engine stalls. There they meet Heidi [Tiffany Mulheron], Lotte [MyAnna Buring], Anke [Louise Dylan], and Trudi [Ashley Mulheron], and they are coaxed aboard to join a night of uncertain plans. The mood shifts quickly when the village reveals a chilling curse: every female child will become a lesbian vampire on her 18th birthday, a dark legend tied to Carmilla [Silvia Colloca], the Vampire Queen who descended on the village during a blood moon, killing the men and seducing the women.
The lore grows stickier as the Baron's line—Baron Wolfgang McLaren, Jimmy’s ancestral connection—enters the tale with a sacred sword crafted for the final confrontation. Across the centuries, the sword was used to defeat Carmilla, but a curse was left behind: when the blood of the last McLaren mixes with a virgin girl, Carmilla will be resurrected. The night unfolds with a cascade of transformations: Heidi and Anke are turned, and Trudi also becomes one of the undead. Eva [Vera Filatova], the shadowy mistress of Carmilla, tries to pull Lotte into her expanding clan, while the trio of Jimmy, Fletch, and Lotte wrangles with fear, desire, and the looming threat.
The group returns to the cottage, the van is destroyed, and the threat closes in. Judi arrives at the door, and Jimmy—still clinging to hope for their relationship—takes her into the bedroom, a decision that becomes a tragic pivot in the night. Lotte then reveals a crucial secret to Fletch: she is a virgin and wishes to sleep with Jimmy, a confession that intensifies the stakes. The vicar delves into research about the vampire slayer who felled Carmilla, arms himself, and hurries off to find Jimmy.
Judi’s true nature as a vampire is exposed, and after a tense struggle, Fletch and Jimmy kill her. The vampires close in on the cottage, and a pivotal mistake occurs when Jimmy inadvertently invites them inside. Eva learns that Jimmy is the descendant of the baron, and that Lotte is a virgin, and she abducts them to further Carmilla’s cause. The vicar—resolved to protect the living—rescues Fletch from Trudi and shares the troubling truth about the village and Jimmy’s lineage. They chase after Jimmy and Lotte in the crucifix‑strewn car, a relic-laden ride that feels almost like a last beacon of hope.
As the shadow of sacrifice looms, the vampires prepare to offer Lotte and Jimmy as a conduit to Carmilla’s return. Fletch and the vicar scramble to recover the Sword of Daeldo from the baron’s tomb, a weapon that could finally end Carmilla’s threat. While Fletch works to pry the tomb open, the vicar checks on his daughter Rebecca [Emer Kenny], only to discover she has already been turned. Rebecca attempts to seduce Fletch, but the moment turns deadly when she is accidentally impaled on the very sword that could save them all. Fletch chooses not to reveal what happened to the vicar.
At Carmilla’s tomb, Lotte confesses her love for Jimmy, and the vampires begin draining their blood in a desperate bid to resurrect the Queen. With the sword in hand, Fletch and the vicar race back toward Carmilla’s resting place. They reach Jimmy and Lotte, but the trail of danger doesn’t end there—the vicar sacrifices himself so the others can reach the car and claim the sword. Eva separates Lotte from the men, torquing the tension as Lotte fights back while Fletch and Jimmy fetch weapons. Lotte strikes a defining blow, killing Eva with her cross necklace and incensing Carmilla.
The fight intensifies as Fletch makes a daring move to kill Carmilla before Lotte is turned, but he is captured. In a final act of courage, Jimmy hurls the Sword of Daeldo, piercing Carmilla’s heart and shattering the ancient evil. With Carmilla defeated, the village’s curse begins to lift, and the surviving trio—Jimmy, Fletch, and Lotte—decide to continue their mission to rid the world of evil, reaffirming their bond and a new sense of purpose in the face of a lingering, volcanic legend.
