Kath, portrayed by Winona Ryder, embarks on a peculiar journey with Max, played by John Gallagher Jr., as they head to a secluded cabin in the woods in the dead of night. Kath, who is in her middle age, shares the road with Max, who is a decade younger. Upon arriving at the cabin, they discover that it has been double-booked. Al, played by Owen Teague, attempts to dislodge them, yet Greta, portrayed by Brianne Tju, graciously offers them a place for the night, setting up an unusual dynamic. Both Al and Greta are in their twenties, wearing matching green coats, an outfit that becomes significant as the story unfolds.
Inside the cabin, they stumble upon a game called Pillow Talk, which claims to "reconnect lovers." As the game progresses, Kath recounts her romantic history with Max; she reveals she is a horticulturist who teaches adult classes and met Max when he was a student. The game takes an unexpected turn when Greta is prompted to lick Max's elbow, leading to an awkward encounter that leaves Kath feeling uneasy. Retreating to her room, she is unprepared for what the morning holds.
When dawn breaks, Kath wakes to an abandoned cabin and ventures into the woods, where she finds Al, who is clearly distressed. He reveals that Max and Greta have seemingly left together, shaking Kath to her core. Back in the city, she processes the surreal turn of events with a friend, who nudges her to uncover Greta's identity. Despite not finding Greta online, a search of the cabin's ownership leads Kath to contact Nicholas Barlow, portrayed by Dermot Mulroney. Although Nick is reluctant to give away Greta's phone number, he agrees to meet Kath at her nursery store to pick up a book.
During their encounter at the store, an unexpected acquaintance recognizes Nicholas and divulges his impressive background as a retired scientist who was once involved in biotech. He opens up to Kath about leaving his career to care for his father, who suffered from a genetic degenerative neuron disease. His work is now focused on seeking a treatment for this illness, which Kath keenly inquires about.
The narrative flashes back to a week prior when Kath hosted a dinner party for her Gen-X friends. During this gathering, Max expresses discontent, inadvertently leading to his fateful encounter with Al and Greta in a liquor store. The film intricately weaves these moments, bridging the past and present, as Kath and Nicholas surveil Greta to learn more. Their investigation culminates in a confrontation during a house party that forces Kath to face the disturbing situation head-on.
As the plot thickens, Max's connection with Greta unfolds, leaving him entangled in a dangerous web. The tension peaks further when Kath discovers through Nicholas that Al is his son, sparking horror and confusion in her mind. Her quest takes a dark turn when Kath finds Max in a precarious situation, raising questions about ethical boundaries, love, and the cost of youth.
As secrets unravel, Kath plays on Nicholas's emotions, suggesting she too desires the transfusion, which spins the plot into a thrilling conclusion. The dynamics between Kath, Nicholas, Al, and Greta make for an intense climax, firmly depicting the lengths one might go to in pursuit of youth and the ramifications of those choices. With a powerful conclusion, Kath stands at a crossroads, gazing out from the cabin's window, contemplating the turmoil that has unfolded, embodying the film's central themes of love, betrayal, and the fear of growing old.
