In a quiet suburban neighborhood, chaos erupts when a mother discovers her dog's mutilated body displayed gruesomely on the lawn. Meanwhile, in their classroom, a slideshow showcasing Brigitte (Emily Perkins) and Ginger Fitzgerald (Katharine Isabelle) explores staged deaths for a school project. Their teacher, Mr. Wayne, becomes suspicious and calls them in for a meeting post-class. Embracing teenage rebellion, the girls sneak out, lighting cigarettes and gaming on the field while mocking their peers and visualizing their demise.
As the tension escalates, the rumors spread when Trina Sinclair’s (Danielle Hampton) friend overhears Brigitte’s morbid depiction of Trina’s fate. Amidst the chaos, a confrontation leads to Brigitte being pushed into the remains of a dog, a victim of the Beast of Bailey Downs, a feral creature terrorizing the neighborhood. Undeterred, the sisters hatch a plan to kidnap Trina’s dog, intending to feign the beast's involvement in its supposed disappearance.
On their quest, they stumble upon yet another gruesome dog carcass. In a twist of fate, as they attempt to retrieve it, a leg detaches in Brigitte's hand—a moment soaked in blood as she mistakenly believes the crimson is from the dog when, in reality, it is from Ginger's first menstruation. Darkness descends when the Beast attacks, dragging Ginger into the woods. Brigitte valiantly rescues her, but the encounter leaves deep marks, both physically and emotionally.
As days pass, the unsettling transformation begins for Ginger; she begins healing rapidly but at an alarming cost, sprouting hair and a tail as she grapples with her monstrous side. The sisters’ bond frays as Ginger explores her new desires, leading her down a spiral further into darkness, and culminating in the shocking death of a neighbor's dog—an act that terrifies Brigitte.
In her desperation, Brigitte turns to Sam ([Kris Lemche]), and together they uncover the truth about the Beast—the impending doom draped in the spirit of a lycanthrope. Sam, suggesting a silver ring as a remedy, highlights the urgency, but Brigitte’s efforts to pierce Ginger’s navel prove futile. Their dilemma deepens when Trina confronts the Fitzgeralds, claiming her dog has been taken. Here, chaos unfolds as Trina slips and fatally injures herself, prompting panic and the hasty concealment of her body in the freezer.
Facing the repercussions of their actions, Brigitte and Ginger spiral deeper into a world of guilt and fear, attempting to divert attention by pretending Trina's death is a cruel joke. Their mother begins to suspect something sinister, leading to a frantic struggle for both sisters as they see their once unbreakable bond now splintering under the strain of their situation.
On Halloween night, Brigitte takes desperate measures, using monkshood in a last-ditch effort to save Ginger—her sister increasingly consumed by darkness and violence. As the sisters’ lives intertwine fiercely and dangerously with their mortality, Brigitte finds herself entangled in a web of violence, loss, and sacrifice that forces her to confront unspeakable horrors.
When the inevitable confrontation with Ginger-Wolf arises, the once inseparable sisters clash under the moonlight, revealing twists of loyalty and despair. In a climactic showdown, Brigitte chooses between hope and pain, ultimately opting for the knife—a painful tribute that seals their fates as the movie nears its heart-wrenching conclusion. Amidst sobs and heartache, Brigitte listens to Ginger-Wolf's breath slow to a stop, forever haunted by their shared journey of darkness.
