The film begins with an inner monologue from a young woman, who expresses her anxious thoughts about contemplating ending her relationship. Though she cannot pinpoint how long she has been feeling this way, she acknowledges that her month-long relationship with Jake feels significantly extended.
Set in the depths of winter, Jake is taking her on a road trip to introduce her to his parents in a rural area. As she waits on the street corner for his arrival, she becomes increasingly regretful for agreeing to this trip without breaking things off first. Throughout the car ride, the young woman occasionally drifts into her thoughts, ignoring Jake's attempts at small talk. They pass a demolition site featuring a swing set, prompting her to remark on the strangeness of this juxtaposition.
As their journey continues, the snowfall intensifies, while their conversations dive into deeper, philosophical matters. The characters demonstrate an analytical nature and a profound education on various topics. At one point, Jake calls her “Lucy,” although she is referred to by different names throughout the film. When Jake turns on the radio to sing a song from the musical Oklahoma!, she is taken aback to learn of his fondness for musical theatre.
The young woman recites a lengthy poem reflecting on the comfort of home, intertwined with existential dread upon arrival. The themes of loneliness, regret, and the terrifying passage of time resonate deeply with her, eliciting a recognition from Jake, who feels the poem encapsulates his own experiences.
Interspersed throughout the film are glimpses into the life of an elderly janitor, showcasing the same swing set in his backyard. His existence is marked by solitude as he observes students rehearse for a school production of Oklahoma!.
Upon arriving at Jake's parents' farmhouse, tensions arise when Jake initially hesitates to enter. Instead, he insists on showing her the stable first, where they discover several deceased sheep. Jake sidesteps questions about their demise, instead recounting an unsettling tale of a pig from his childhood that met a grim fate.
Once inside, they initially find Jake's parents missing, only to later discover them upstairs getting ready. Jake gives the young woman a tour of the house, where she is reminded of her childhood home. A baby photo on the wall unnervingly resembles her, creating a moment of confusion. When they come across the basement door, covered in scratches and taped shut, Jake warns it is unsafe, implying the markings originate from the family dog.
Dinner time reveals Jake's parents to be both welcoming and unusual. As the young woman presents her artwork, she notices their inability to engage with it meaningfully. She shares the story of how she and Jake met at trivia night, although her narrative is riddled with inconsistencies. The father interprets everything literally, while the mother mispronounces words and laughs hysterically, rendering her comprehension questionable.
Mid-dinner, the young woman receives an ominous voicemail from someone identified as "Lucy." The cryptic message underscores her growing fear and uncertainty. Despite the unsettling tone of the voicemail, she remains composed and continues the dinner conversation.
As dessert is served, she muses about studying Gerontology, critiquing societal treatment of the elderly. This conversation is interrupted by Jake's mother, who is momentarily overtaken by a sound in her ears attributed to tinnitus, wondering aloud if someone is attempting to share universal secrets.
As the evening progresses, odd occurrences escalate—Jake's parents appear to age and reverse between scenes, and the young woman finds herself in Jake’s childhood bedroom, discovering a journal that contains her own poem.
Amid the bizarre atmosphere, Jake’s father wrongly believes the young woman plans to stay the night. Despite her insistence on returning home, he offers her Jake's childhood bed and a stained nightgown from his mother. Afterward, the mother sends her to the basement for laundry, where she receives another mysterious call echoing the prior message. She discovers a flooded washing machine full of identical shirts and several paintings signed by Jake that resemble her artwork.
The young woman ultimately persuades Jake to depart, but their return trip is plagued by a worsening blizzard. During the ride, Jake mistakenly calls her “Amy,” further blurring her memory of events at the farmhouse. Their discussion transitions to the film A Woman Under the Influence, where she critiques it extensively, suddenly adopting an air of condescension. Jake, feeling emotionally connected to the film, struggles to articulate his thoughts.
Jake impulsively decides to stop for ice cream at a place called "Tulsey Town." The young woman recognizes one of the employees but cannot remember her. The employee cryptically suggests that Amy shouldn't press forward with her journey.
After leaving the ice cream shop, Jake pulls over at his old high school to dispose of the ice cream cups. He disappears inside, leaving the young woman alone for an unsettlingly long duration. When she eventually extracts herself from the vehicle, she inadvertently locks herself out.
Seeking Jake, she encounters the janitor, initially trying to evade him but ultimately engaging in conversation. She reveals that nothing significant occurred between her and Jake on trivia night and admits she cannot visualize Jake's face.
Reuniting, the couple crosses paths with two dancers who mimic their movements, launching a surreal, dreamlike ballet sequence. This performance culminates in a dance fight, leading to Jake's demise at the hands of the janitor.
Concluding his shift, the janitor hesitates in his truck, broken by the burden of his thoughts. Hallucinating characters from a Tulsey Town commercial, he follows an animated pig reminiscent of one from Jake's earlier story.
In the high school auditorium, an aged version of Jake delivers a Nobel Prize acceptance speech discussing his metaphysical journey, while Lucy/Amy observes from the audience, along with others who appear much older. His speech culminates in singing "Lonely Room" from Oklahoma!, a poignant reflection of isolation and empowerment.
The film's denouement reveals a quiet school parking lot blanketed in snow the following morning. As the storm subsides, a faint sound of an engine starting resonates, possibly indicating that Jake has reconsidered his stance on ending things.
