On a chilly afternoon, with snow blanketing the ground, the high school band rehearses for their final football game when suddenly, they hear gunshots. The story unfolds through flashbacks that take us a few weeks prior. We meet Arthur (Michael Angarano), a high school student who spends his days working as a busboy at a local Chinese restaurant. There, he interacts with Annie (Kate Beckinsale) and Barb (Amy Sedaris), who are both waitresses. Annie, once Arthur's babysitter, finds herself navigating a complex life. She is recently separated from her husband Glenn (Sam Rockwell), who is attempting to reclaim his life, working at a new job, and striving to prove his worth in hopes of seeing more of their young daughter Tara (Grace Hudson). Annie also bears the weight of caring for her ailing mother.
Glenn, still residing with his parents, aspires to build a career in real estate despite being employed at a carpet sales job that his father considers beneath him. Simultaneously, Annie finds herself entangled in an affair with Barb’s husband, Nate (Nicky Katt), a relationship that only deepens her discomfort and guilt, as it betrays her friendship with Barb. Their clandestine meetings take place at a motel outside town, which happens while Glenn looks after Tara for the day. During this time, Glenn shows an interest in rekindling his relationship with Annie, even inviting her out on a date. Yet she remains unimpressed with his lackluster job status, and suspicions arise about her fidelity.
Meanwhile, Arthur struggles with a chaotic home life dominated by the stark contrast between his clashing parents, Louise (Jeannetta Arnette) and Don (Griffin Dunne). Recently, Louise ejected Don from their home for his failures as a husband and father. Caught in the emotional turbulence, Arthur finds himself drawn to Lila (Olivia Thirlby), a new girl in school with a passion for photography, who aims to capture memories in the yearbook with the hope of earning art credit.
As tensions rise, Barb begins to suspect Nate’s infidelity when she discovers a motel receipt in his clothing, igniting her anger, especially since she works tirelessly to support him. The weight of the betrayal festers, and when Nate seeks to confront Annie, it only adds to the brewing chaos. A fateful encounter between Barb and Annie occurs at the restaurant the following day, where Barb confronts Annie, demanding she resign. However, Annie, in need of a paycheck, finds herself torn.
Glenn grows increasingly aggressive, confronting Annie about her perceived sleeping arrangements with Nate, eventually leading to a confrontation outside her home. In an alcohol-fueled rage, Glenn causes a scene, upon which Annie resorts to pulling a gun to ensure he leaves her property. In a heartbreaking twist of fate, Tara, overwhelmed by unrest in her surroundings, wanders off unnoticed while Annie, weakened from the pressures of her life and guilt, sleeps exhausted on the couch.
When Annie awakens to find Tara missing, panic sets in as she frantically searches the neighborhood, enlisting Barb in her desperate plea for help. The police become involved, bringing Glenn in from work to eliminate him as a suspect in Tara's disappearance. As the community bands together, the school closes early to mobilize students in the search efforts.
Hours of searching lead to a tragic discovery: Arthur, in a moment of rebellion, stumbles upon Tara's lifeless body after she falls through the ice while playing near the lake. The aftermath leaves Annie shattered, not only with grief but also knowing her choices have tangled her life into a web of sorrow. In the wake of Tara's death, both Glenn and Annie’s troubled relationship reaches a boiling point. Glenn, unable to forgive Annie's infidelities, becomes embroiled in further conflict when he learns of her affair with Nate, serving as a raw reminder of his own failures as a father.
Amidst the turmoil, Arthur grapples with his own feelings of betrayal as he watches Don attempt to re-enter their fractured family unit while simultaneously flirting with infidelity again. Enraged by the chaos surrounding him, Arthur pressures Don to make an uncompromised decision about his family.
Ultimately, Glenn's grief consumes him as he seeks Annie out, breaking into her home with a shotgun, burdened by heartbreak and the haunting memories of their lost daughter. Upon Annie's return, Glenn forcibly drags her into the snowy woods, leading to a chilling standoff that culminates in an ambiguous and tragic end, leaving viewers to ponder the fate of both characters following the harrowing gunshots that interrupted the earlier narrative.
