After a zombie apocalypse, Mike and Kim reinforce their cabin in the woods, eking out a fragile existence. The duo weather an exhausting routine where supplies dwindle, and the man on watch keeps a meticulous tally of the zombies he destroys. He communicates his presence with a rhythmic series of knocks set to familiar rock songs—a strange, almost ritualistic way to identify himself and prove that he has not become infected. The warning signs of infection loom close by, with symptoms described as dark, almost unnatural features: black irises, black blood, and violent paranoia. These unsettling details color the tense atmosphere as they argue about the next steps for survival, weighing caution against hope.
As the supplies run thin, [Mike] insists they should return to hunting for food, but [Kim] would rather stay put, clinging to the safety of their cabin. The disagreement becomes more pronounced when flashbacks reveal a grim memory: a second couple, [Todd] and [Erika], had once lived with them until tainted meat sickened them all. The truth that follows is brutal and blunt—the pair, and even their own baby, were forced to die after consuming the tainted food. The weight of that memory haunts the present as they reckon with fear, scarcity, and the fragility of trust in a world where danger can strike from any direction.
While [Mike] goes out on a scavenging run, a call comes in on a walkie-talkie from a man who identifies himself as Ranger Mark. Initially, the message is seemingly helpful, offering aid and a sense of companionship in a desperate time. Yet the tone shifts as the communications grow abusive and misogynistic, revealing a more sinister threat lurking beyond the forest. Kim keeps these calls to herself, not telling [Mike] about the escalating menace. The isolation grows heavier, and the sense that any ally might be a mirage intensifies the looming dread.
An unproductive outing convinces [Mike] that the area has become too dangerous for their meager supplies. He proposes a drastic plan: move to the coast, where they could live in a mansion, operate a generator, and perhaps reclaim a semblance of normal life. The idea tempts Kim, who yearns for safety and stability, but the reality of leaving everything behind proves too daunting for one partner to undertake alone. She agrees to the plan in principle, yet the stubborn barrier of trust remains, and she chooses to stay vigilant rather than step into the unknown with him.
Back at the cabin, Kim experiences a relentless barrage of nightmares and hallucinations. Erika and her baby appear in haunting visions, and Ranger Mark’s taunting grows louder in her mind, turning the past into a relentless echo that gnaws at her resolve. Paintings seem to move on their own, as if the house itself is complicit in the fears that have taken up residence inside her. The boundary between memory and present danger fractures, and Kim’s sense of safety slips away with each waking moment.
When [Mike] finally returns, a crucial moment of misfire shatters any remaining sense of normalcy: his coded knock is wrong. The suspicious signs mount—blood on his skin and visible cuts—which prompt Kim to repel him from the doorway. He protests that he is not infected, but her distrust deepens, the old patterns of fear and resentment surfacing in a fight for control and safety. The tense stalemate pushes him to try to break the entry, and in a desperate act of self-preservation, she cuts off several of his fingers to prevent him from forcing his way back in.
Recovery brings a grim clarity: the relationship has fractured beyond repair. He awakens to find that he is bound to a chair, and the conversation turns toward the impossible question of what to do next. Kim’s conviction that the other remains tainted—infected despite his protests—forces a brutal conclusion: she ends his life. The horror isn’t over, though. A spark of defiance or perhaps a final superstition erupts as she dances in the yard, thinking she has escaped the nightmare that has defined their days. But the nightmare returns in a new form: Mike’s reanimated corpse attacks, and she kills him again, this time with a grim, ritual certainty.
In the final shot, the vision she has fought to survive reveals its final, chilling truth: her irises and the blood she carries have turned pitch black, a stark, unambiguous symbol of how far she has wandered into a world where hope, humanity, and danger fuse into one irreversible nightmare. The stillness of the ending lingers, a stark reminder that survival in this world comes at a price that can redefine one’s very being.
