Two married couples — Debs Alexandra Daddario and Josh Daveed Diggs, and Mitch Josh Gad and Melanie Ashley Park — spend New Year’s together in a snowbound cabin high on a mountain. Debs is an author who has published one novel but works as an editor, while Josh is a skilled nature photographer. Mitch is a financial manager who has just earned a promotion, and Melanie is currently unemployed after publishing two cookbooks. Debs and Mitch share a long friendship with each other, a foundation that will be tested as the night unfolds.
On the morning of New Year’s Eve, Debs and Mitch hike up the mountain, their pace cautious after a tense few days. A tree nearly crashes down on them, forcing a quick retreat to the safety of the cabin. Through the window, they glimpse Josh and Melanie in a moment of intimacy, an image that leaves them shaken and unsettled. Debs wants to confront the couple, but Mitch urges restraint, insisting they need time to process what they’ve seen before saying another word.
When Debs senses the heater is failing, she reaches out to Gary Kevin Pollak, the house owner who rents the place to them, and asks for help. The group struggles to regain their composure as buried resentments and doubts surface: Debs is wrestling with writer’s block on her second novel, Mitch is unhappy in his job, and Josh hints that Debs’ first novel may not be entirely authentic to her voice. Debs is torn between speaking up and staying quiet, while Mitch feels unsteady about how lucky he appears to have landed Melanie. The tension grows when Josh boasts about his National Geographic work, prompting Debs to question his honesty in a quiet, pointed way.
The situation takes a sharper turn when Melanie finally admits that she and Josh had sex. It’s a revelation that shocks Mitch to his core and makes the night even tenser. In the wake of the confession, Mitch tries to leave, but a heavy snowstorm locks everyone inside the cabin, trapping them in their rooms and forcing further conversations that would otherwise never happen.
Gary arrives again to fix the heater, and a kitchen confrontation shatters several bottles of alcohol. The four choose to talk through their issues in private spaces, trying to parse truth from defensiveness. Both Josh and Melanie insist the fling was a one-time impulse, yet they differ on who initiated it. Melanie reveals she acted out of feeling like a burden, given Mitch’s regained employment, while she remains unemployed. Debs, speaking with rare candor, admits she nearly cheated on Josh with a musician she writes about, sensing a stronger connection there than with the person she is with.
As Mitch helps Gary repair the heater, he discovers a dead squirrel lodged inside the mechanism and, tucked away, a bottle of unusual liquor left by the previous occupants, famous in local legends as a bootlegger’s stash. Gary warns of potential side effects. Mitch drinks and slips into a lucid state where he imagines a future in which Debs and he could be a couple, but Debs gently rejects the idea, reaffirming her commitment to Josh. Josh and Mitch engage in a charged exchange about truth and loyalty, while Melanie joins the two men with a drink. By the time the alcohol flows freely and the clock edges toward midnight, all four have gathered again, and Debs finally takes a cautious drink as the new year begins.
As the night progresses, the four open up in ways they hadn’t before. Josh confesses that he struggles with his own self-image, and while he doesn’t dismiss Debs’ first novel, he questions whether it truly reflects her. Debs admits her second manuscript is finished but she fears exposing it to others. Melanie confesses that she doesn’t feel they truly know each other, and she reveals that someone else wrote her second cookbook. They eventually venture outside to verify the fallen tree and watch the sunrise together, a fragile moment of shared reality after a night of emotional upheaval.
In the aftermath, Debs and Josh decide to work through their differences, while Mitch and Melanie choose to separate. Debs hands Mitch a copy of her new manuscript to read, a gesture that signals a shift in their friendship and relationships. Debs and Josh drive away together, while Melanie heads to her parents, and Mitch remains at the cabin for a while longer to process what happened and what comes next. The quiet morning light wraps around them as each of them steps into an uncertain future, having confronted the layers of desire, ambition, insecurity, and honesty that defined their New Year’s confrontation.
