Spike [Alfie Williams] has been found by The Fingers, a Satanist cult led by Sir Jimmy Crystal [Jack O'Connell]. The group wears unflattering blonde wigs modeled after a notorious predator, and their ranks include Jimmy Ink [Erin Kellyman], Jimmima [Emma Laird], Jimmy Fox [Sam Locke], Jimmy Jimmy [Robert Rhodes], Jimmy Snake [Ghazi Al Rufai], Jimmy Jones [Maura Bird], and Jimmy Shite. In a brutal initiation, Spike must fight and kill one of the Jimmys to join the Fingers. He faces Jimmy Shite, who taunts him and drives him to the edge, until Spike exposes Shite’s pants and thrusts a knife into his thigh. Shite bleeds out after a ruptured artery and dies; Sir Jimmy proclaims Spike a new “Jimmy,” sealing his place in the circle.
On the outskirts, Samson [Chi Lewis-Parry] feasts on another kill while the world around him creaks with danger. Nearby, Dr. Ian Kelson [Ralph Fiennes] retrieves the corpse of a pregnant infected woman—the one who gave birth to Baby Isla—and adds her remains to his Bone Temple. Kelson then tranquilizes Samson with morphine, keeping the creature calm as the night drifts by. It soon becomes clear that Samson seeks out the drug, visiting Kelson almost as if drawn by a calm, lucid state, and the doctor watches the sky with him while a Duran Duran track hums in the background.
A trio of survivors trudges through the woods in search of safety: Tom [Louis Ashbourne Serkis], his pregnant partner Cathy, and their companion Jonno [Gordon Alexander]. They move with stealth to avoid the infected, but danger closes in as they’re spotted. Jonno fights to protect them, cutting through the danger with grit, but the savage life of the woods bites back when his blood spills and infection takes hold. Tom and Cathy return home features a farmstead that has fallen under the Fingers’ control, where they find George [David Sterne], Matthew [Elliot Benn], and Jane (Lynne Anne Rodgers) living under the oppressive grip of Sir Jimmy’s cult.
Inside the barn, Sir Jimmy directs the dark theater of sacrifice, forcing Jimmima to dance to an unsettling fixation on a children’s program, while the brutal ritual edges closer to its terrifying climax. Matthew’s desperate counterattack—boiling water hurled in an attempt to free them—creates a brief chaos, allowing Cathy to slip away, though many are captured and corralled for what follows.
Kelson continues his unsettling dance with Samson, savoring the vulnerability of the drugged figure while the clock ticks down. When night falls, Kelson prepares to euthanize the creature, only to be moved by a sudden, almost prophetic moment—the Alpha looks to the sky and utters a word: moon. This small sign sparks a renewed sense of possibility in Kelson, who weighs the consequences of his choices.
The Fingers herd the captives into the Bone Temple and set up a ritual that culminates in fire, gore, and a chilling sense of ritualistic menace. Sir Jimmy is enthralled, while Spike, still in the mix, is drawn toward the flame-lit spectacle but remains a step away from it as Ink [Erin Kellyman] begins to see the truth behind the madness. Kelson’s moment of performance art—flames, hallucinogens, and a thunderous soundtrack—concludes with an ominous order: the Fingers must obey Sir Jimmy, and the cult will continue its ghastly work. Ink, sensing the danger, acts decisively: she stabs Sir Jimmy when he tries to bristle with authority and then annihilates the remaining Fingers, stepping into the role of protector as she drags Spike away.
As the chaos quiets, Ink unveils her true name to Spike: Kelly. They move off into the woods, while Samson returns, and a drug-weakened Sir Jimmy—crucified upside down and tasting the end of his reign—sees visions of Satan as he carries Kelson’s body toward the night. The infected close in, finishing Sir Jimmy’s story in the glow of burning embers and shifting shadows.
In the distance, Jim [Cillian Murphy] and his teenage daughter Sam observe from their cottage, listening to the distant commotion. They arm themselves and head out, prepared to defend a pair they have only just met, hinting at a fragile hope that survives even as the world teeters on the edge of collapse.
