Four sisters—Caroline, Joanna, Paulina, and Vicky—come together during the festive season to celebrate Christmas at the picturesque Yorkshire mansion owned by Caroline and her husband, Peter. Caroline, with an intense fixation on perfection, ardently wishes to ensure that every detail of their gathering is flawless; however, as fate would have it, things veer off-course from her ideals.
The chaos begins on December 22 when the Christmas tree takes a tumble, prompting Peter and his children, Daisey and Henry, to transform the tragedy into a creative opportunity by redecorating it with handmade ornaments. Vicky, the vibrant and youngest sister, is the first to arrive, followed closely by Joanna, who brings along her boyfriend Felix and their mother. Paulina arrives somewhat tardily on foot, with their uncle John observing the family's dynamics from a distance.
As they gather around the tree, Joanna's critical eye surveys the decorations, reflecting her displeasure as she shows little enthusiasm for her lively niece and nephew. In contrast, Vicky, effusive and free-spirited, joyfully shares trinkets sourced from her recent adventures couch-surfing across the U.S.
The warmth of the fireplace invites the adults to move into the library, where Paulina is diligently focused on her thesis about the legendary Beatles. Meanwhile, Caroline insists on presenting the meticulously planned holiday schedule. Tensions boil over when Joanna becomes increasingly irritated at Vicky's jokes about her age, leading her to announce that she and Felix will be opting out of the festive spirit and staying in town instead.
Before they part ways, Vicky accidentally reveals that she recently spent two weeks with their estranged father James and his much younger girlfriend Jackie in Florida, jaw-dropping news that leaves the other sisters stunned. Their mother enters just in time to witness the shock among her daughters.
As they congregate near the fire in reflective silence, an unexpected car pulls into the driveway. Vicky had invited James and Jackie to join their Christmas festivities without so much as a heads-up to anyone else. After the introductions and the subsequent tea, the sisters find a moment to retreat and voice their critiques of Jackie’s American accent and youthful appearance, noting her remarkably young age of only 35 years.
Upset and fed up with the criticism, Vicky takes off in Felix's luxurious Rolls-Royce, while backstories unfold revealing Joanna's profession as a fashion editor, attributing her high-end clothing to her work benefits. That night, Vicky finds herself at the village pub, where she charms the bartender, leading to an incredibly memorable evening. Not far behind, their mother also ends up spending the night with John.
As the 24th arrives, the family heads out to support a local fundraising event for their church. Vicky takes the initiative to sell Joanna's stylish clothes at absurdly low prices, even offering Felix's car as a raffle prize. The couple must engage in somewhat humiliating challenges to reclaim their possessions, with Joanna needing to buy back her clothes while Felix spins to win back his vehicle.
Tensions ignite again during lunch when John silences James, prompting them to step outside for a confrontation. In a twist of fate, James surprises everyone by proposing to Jackie. Later, he approaches his daughters, apologizing for his departure a staggering 27 years prior but justifying his absence by explaining he financed their lives unknowingly while being updated by their mother all these years. The girls casually invite him for drinks at the pub, a complex mixture of emotions surfacing throughout.
Returning to the mansion, the family returns from a lengthy drinking session to discover Jackie has organized a spectacular New York-style light show, only for it to inadvertently short-circuit the manor's antiquated electrical system. As darkness envelops them, Peter hands out blankets for warmth, while Joanna sneaks in and out of Caroline's bathroom with undisclosed intentions.
On Christmas Day, amid the revelations and chaos, Peter uncovers a somewhat shocking pregnancy test in their bathroom. Convinced that it belongs to his wife, he hastily storms out intending to end their marriage. Caroline, however, confronts everyone about the situation, leading Joanna to admit the test belongs to her. Amidst the fallout, their mother unveils a long-held secret caked in shame—the reason behind their family’s heartbreak: James fled upon learning of her pregnancy with John, thus revealing Vicky as John's biological daughter.
With emotions running high, the family races to town to witness the children's nativity play as James seeks out Peter to make amends. Ultimately, the meticulously planned Christmas dinner Caroline prepared must be abandoned as the family finds themselves at a nursing home, delivering meals to those in need, shaping a different kind of holiday spirit altogether.
