Unhappy married couple Miriam and Caleb drive to the secluded home of Miriam's sister Greta and her husband Dylan to help prepare for Dylan's upcoming family reunion. Despite tension between Miriam and Caleb, they have an easy rapport with Greta and Dylan, who has known the sisters since high school. Greta privately offers Miriam marital advice, and Miriam implies that she envies Greta's successful marriage. Later, during a drunken campfire conversation after the others have gone to bed, Miriam kisses Dylan, then apologizes and reveals her marital problems and insecurities, to which Dylan is sympathetic. Early the next morning, Dylan begins sexually assaulting Miriam while she is asleep. She wakes and implores him to stop, but he persists. Miriam then wanders into the forest, where she encounters a wolf carrying a slain rabbit. She returns to the cabin and initiates sex with Caleb, but he rebuffs her. She later confronts Dylan about the assault, but he denies responsibility, claims that she wanted to have sex with him, and assures her that he will not tell Greta what happened. During a swim in a nearby lake, Miriam tells Greta about the assault, but Greta refuses to believe her and suggests that Miriam is trying to cover up an attempted seduction of Dylan. That night, while the group prepares for dinner, Dylan tells Greta that he slept on the couch after the night by the campfire, upsetting Miriam, who behaves aggressively towards the group and embarrasses Caleb by claiming that he secretly dislikes Dylan and Greta. The day before the family reunion, Miriam lures Dylan to a guest cabin on the pretext of another sexual encounter. She convinces him to strip naked and be blindfolded, asking him what it felt like to assault her, then bludgeons him unconscious. She ties him to a chair and duct-tapes a plastic bag around his head. As he begins to suffocate, she tears the bag out of remorse. Dylan headbutts her and breaks his restraints. After a struggle, Miriam finally chokes him to death, crying afterward. Miriam collects Dylan's blood in containers, dismembers his corpse, and saves some of the bones, which she later pulverizes with a sledgehammer. After clearing evidence from the scene, she burns the rest of the body and scatters the ashes across the water. She then dons a wig and travels to a motel, where she encounters a couple arguing. She interjects and loudly rebukes the man, much to the couple's surprise. In her motel room, Miriam pours the corpse's blood down the bathtub drain and cleans the tub. On the day of the family reunion, Miriam makes final preparations with Greta, who is furious about Dylan's unexplained absence. Miriam describes a dream in which she discovered Greta
hanging from a belt and felt guilty for not responding sooner, to which Greta responds with disgust. Miriam insists that Dylan is not the right partner for Greta, which prompts Greta to claim that she only invited Miriam and Caleb at Dylan's suggestion and that Miriam is self-righteous and overprotective. Miriam makes ice cream for the reunion by herself, secretly adding Dylan's powdered bone to the mix. Greta rejoins Miriam after calming down and asks her if she survived in Miriam's dream. Miriam responds that she tried to hold Greta up and offer words of reassurance, wanting her last experience to be one of love rather than panic. Greta tearfully assures Miriam that she loves her. During the reunion, Greta sits beside Miriam, and, along with many of Dylan's relatives, enjoys an ice cream cone while Miriam quietly cries. ==Cast==