Set in Kringletown, a year-round Christmas town high in the Colorado Rockies, the story follows Atlas Peter Maxheimer, known as Max, the youngest of three brothers in a family that owns and operates Evergreen Farm, a Christmas tree farm with vendor booths, a gingerbread house, and a reindeer barn. A metafictional Narrator, later revealed to be BKJ (Bob Krampus Junior, the son of the town's Santa figure and unofficial mayor), frames the story throughout.
On Thanksgiving Day, Max bursts into his family home claiming he heard "invaders" on the vacant property next to the farm, discussing land development. His parents, brothers Felix and Ansel (who co-own Toboggan Tours, a local touring company), and his best friend Cole Black all dismiss him as dramatic. The next morning, Max discovers his parents have left on a surprise trip to the European Christmas markets and will not return until Christmas, leaving him to oversee the farm and prove he can eventually take it over.
The Narrator introduces Betty, who has come to Kringletown to visit her Uncle Dwight, the owner of the vacant thirty-acre parcel adjacent to Evergreen Farm. Betty is reeling from the failure of her year-round Christmas shop in Fort Collins, unemployed and living in her parents' basement. Dwight pitches her on running a competing Christmas farm on his land. Despite her fear of failing again, Betty agrees.
Max and Betty bump into each other twice on town sidewalks, bundled in winter gear that hides their identities. They share playful, flirtatious exchanges but neither learns the other's name. Meanwhile, Betty scouts Evergreen Farm per Dwight's instructions, asking about vendors and suppliers. Kate, who works the farm's register, reports the snooping to Max, deepening his suspicion. Betty also meets Cole's wife, Storee Black, at the farm, and Storee warmly offers friendship.
Dwight sets Betty up in a small prefabricated cottage on his property, complete with her belongings, her car, and her pet tarantula Buzz. That night, Max sneaks onto the neighboring property with a flashlight and a crowbar to investigate. Betty flings open her door and hurls a two-liter bottle of Pepsi at his head, knocking him unconscious. She calls the police, and Max is arrested for trespassing.
Their next encounters are hostile. Betty recognizes Max as the intruder when he confronts her at the farm's gingerbread house and throws a tube of icing at his forehead. When Max later brings chocolate-covered pretzels as a peace offering, the bag breaks, Betty panics and hurls a Coca-Cola bottle at his chest. Max explains through her doorway that he was merely investigating his new neighbor, but Betty refuses to believe him.
Max learns from Sherry Conrad, a local gossip, and BKJ that Betty is Dwight Yokel's niece and that a "Coming Soon: With Joyful Ring Farm" sign, advertising a planned competing Christmas farm, has appeared on Dwight's property. Because the land sits just outside town limits, the town's ordinance banning overlapping businesses does not apply. Dwight confronts Max at the farm parking lot, warning him to stay away from Betty and boasting that the new farm will intercept visitors. Dwight also tells Betty that his enmity toward Max dates to high school, claiming Max interfered with his relationship with Jessica, a girlfriend who died of cancer.
Desperate, Max presents friends with a crayon-drawn "Battle Plan": He will woo Betty into falling for him, then dump her before Christmas so she is too heartbroken to continue the rival farm. Everyone rejects the plan. After the group disperses, Storee secretly offers to help under two conditions: Cole must not know, and Max must follow her lead.
Storee orchestrates a series of encounters. She invites Betty for coffee at Warm Your Spirits, the local café, and plants Max there holding Storee's baby, Florence, to look approachable. At a fruitcake-baking competition, Storee deliberately causes a diaper emergency so she and Cole must leave, forcing Max and Betty to sit together. Their conversation is painfully awkward, but moments of genuine connection emerge. When Ansel flirts with Betty, Max grabs her hand and pulls her away, admitting he is intensely attracted to her.
On Cupid Christmas Night, a couples-only town event, Storee arranges for Betty to arrive by pretending to mix up dates. After Cole and Storee slip away, Max leads Betty under mistletoe and kisses her for the first time. They hang ornaments on the town's wishing tree, where tradition holds that a wish comes true if the ornament survives overnight. Lying on blankets beneath the stars, they share stories, but Betty grows withdrawn when the conversation touches on Dwight, sensing a gap between her uncle's portrayal of Max and the man before her.
Storee stages a fake party at Max's house using mannequins and Christmas music. Betty arrives to deliver Max's ornament from the tree and spontaneously kisses him, then grows mortified when she realizes there was no mistletoe. Max hugs her goodbye, confirming she shares his feelings. Betty later confides to Storee that Atlas does not seem like the man Dwight described.
At the café, Max and Betty flirt openly. Dwight walks in and erupts. He reveals his deepest grievance: He once hung an ornament on the wishing tree for Jessica's recovery, and it disappeared overnight. Dwight says he was told a Maxheimer took it and assumed it was Atlas. Betty, devastated, walks away from Max.
A brutal snowstorm knocks out power across the area. Max treks through over a foot of snow to Betty's cottage, where he finds her nearly frozen. He carries her back to his house, sets her before the fire, and ventures back into the blizzard a second time to retrieve Buzz. Warmed and recovering, Betty tells Max she believes he is not the man Dwight described. Their intimacy escalates through the night.
The next morning, Betty proposes an alternative to the rival farm: individual cottages on Dwight's land as an adults-only retreat, filling Kringletown's lodging gap. Max enthusiastically supports the idea. On their first official date, they discover near-perfect compatibility. Max buys her a snow globe matching her vision of red cabins with candy canes. That night, they sleep together at her cottage, and Max stays over. They begin dating exclusively.
Betty refines her "Candy Cane Cottages" concept: individual red-and-white log cabins with hot tubs, a spa, a bar, hiking trails, and a main lodge. Max privately admits to Storee that he is falling in love. His parents return unexpectedly from Europe and walk in on Max and Betty in a compromising position, but the introduction turns warm; Max's mother, Ida, and father, Otto, are charmed by Betty and supportive of her plans.
Cole discovers through archived surveillance footage that it was Ansel, not Atlas, who took Dwight's ornament years ago, having grabbed the wrong one in a botched prank on Felix. Before Max can tell Betty the full truth, she finds his crayon "Battle Plan" in his glove compartment. Dwight arrives at the same moment, reads the diagram, and declares Max was manipulating her all along. Remarks from local townspeople Martha and Mae about searching archives to block Betty's business confirm her fear that the community was complicit. Betty, humiliated and reminded of false friends who abandoned her in Fort Collins, orders Max to leave.
Max confronts Ansel, who confesses and produces the ornament from his safe. Max assembles the townspeople, and together they devise a plan. Ansel returns the ornament to Dwight, who is moved to learn that Jessica herself handmade it. Dwight and Max reach a fragile truce. The group then cuts power to Betty's cottage, forcing her to call Dwight, who drives her into town. A staged commotion on the sidewalk sends Betty stumbling into BKJ's arms. Max steps forward holding chocolate-covered cherries and, before the whole town, confesses that while the wooing plan was real, his feelings became genuine almost immediately. He tells Betty he loves her. She says she loves him too and forgives him. They kiss as the town cheers.
In an epilogue set one year later, Max and Betty are married and expecting their first child. Betty's Candy Cane Cottages are being installed on Dwight's land, on track for a soft opening by Christmas. Max has incorporated several of Betty's ideas into the farm. He and Dwight maintain a functional peace. Ansel, Felix, and Max now meet monthly, rebuilding their sibling bond. BKJ signs off as his father, Bob Krampus, retires from the Santa role.