On a full moon night in the 1980s, Heather first shifts into a wolf, attacking her human mother Patti and revealing a curse she inherits from her father Henry. A few years later, Heather works alongside Henry at a local diner and keeps active by playing hockey with her younger twin brothers, Cooper and Hardy. Patti has slipped into alcoholism, adding tension and complexity to a family already coping with the strange turn Heather’s life has taken.
Around this time, Heather meets a new neighbor, Jonny, a figure skater who recently moved in with her father. Jonny has a boyfriend, and the dynamic between Jonny and Heather grows as they spend time together—Heather is drawn to Jonny, watching her skate at the local rink, and the two eventually bond during outings to a casino with friends. On a night shaped by a full moon, Heather’s condition flares up again as she struggles to head home.
The morning after one such episode, Heather is found unconscious and wrapped in a blanket on Patti and Henry’s doorstep. They urge her to be more careful, but the bond between Heather and Jonny deepens, and the two continue spending time together. Heather even experiences a fantasy in which Jonny feeds her eggs, a moment that foreshadows the vulnerability beneath Heather’s increasingly dangerous exterior. Their closeness is tested when Cooper and Hardy sneak into a bar and discover the two sharing a private moment, and Hardy’s coldness grows as a result of the revelation.
One night, Jonny invites Heather to her house, and the two share a consensual, intimate moment. Heather has another fantasy in which Jonny is naked, and the moment unsettles Jonny, who begins to pull away after Heather leaves. Seeking clarity, Heather approaches Jonny’s father, but he dismisses her concerns, leaving Heather devastated and isolated. A party invitation becomes a turning point: Jonny tearfully tells Heather they can’t talk anymore, and Patti consoles Heather back at home, offering a fragile sense of comfort.
Tragedy strikes when Henry dies of a heart attack at work, his body reverting to wolf form in the moment of death. The family grapples with the loss; Hardy accuses Heather’s sexuality of triggering Henry’s death, while Cooper, who has begun to reconcile with Heather, defends her in the heat of a confrontation with Hardy. The argument spills into the night, and Heather runs out as Patti tries to separate the feuding brothers.
Driven by heartbreak and anger, Heather heads to the bar to confront Jonny, hoping for some closure. Instead, Rick interfere, dragging Heather outside and beating her. In the moment of the ensuing assault, Heather fully transforms, overpowering Rick and disappearing into the woods as dawn approaches.
The next morning, Patti finds Heather naked, bruised, and bloodied at her bedroom door. While Patti helps Heather bathe and heal, she urges her to leave town because the place no longer feels safe for her. Heather drives off into the night, choosing a solitary path away from the life she’s known.
> You can't mess with animals, man. Cardinal rule.
In the post-credits scene, Jonny’s friend Otto is being interviewed about Rick’s death, underscoring a grim truth about the town and the forces that move beneath its surface.
