Malcolm Gephardt, owner of the Half Moon bar in the small town of Gillam, New York, arrives on a Friday evening to find the place unusually packed. A blizzard is approaching, and competing bars have closed early, driving the crowd to his door. Since buying the Half Moon from its longtime owner, Hugh Lydon, two years earlier, the bar has been a financial struggle, and Malcolm's wife, Jess, left him seventeen weeks ago on Halloween. He notices Billy, an enforcer who works for Hugh, sitting alone and watching him, a reminder that Malcolm is behind on payments from a private loan arrangement with Hugh.
The night turns sour when Tripp, a belligerently drunk regular, provokes a younger patron and is punched. Malcolm and his young bartender Roddy move Tripp to the kitchen, but Tripp slips out the back exit unnoticed. After the storm drives customers home, Malcolm's close friends Patrick and Siobhán deliver difficult news: Jess is involved with Neil Bratton, Patrick's college friend, a successful lawyer who recently moved to Gillam after a divorce. Malcolm is blindsided and confirms that Jess has been staying with Neil, not with her mother as he assumed.
The narrative shifts to May 2004, when Malcolm and Jess, then twenty-five and thirty, discover she is pregnant. Malcolm proposes, and they marry at a courthouse, celebrating at the Half Moon. Jess miscarries at nine weeks, but they resolve to try again.
Twelve years later, Hugh offers to sell Malcolm the bar. Years of fertility treatments have drained the couple's savings, so they agree they can only afford the business, not the building. But Hugh privately offers Malcolm a large personal loan to buy the building too, and Malcolm accepts without telling Jess or hiring a lawyer. When Jess discovers the deception through a congratulatory card from Hugh, she is furious. Malcolm deflects by accusing her of unilaterally pushing their fertility treatments beyond what he wanted, exposing a deeper rift.
Jess's perspective unfolds in extended flashback. Over nearly seven years, she endures multiple rounds of intrauterine insemination (IUI) and in vitro fertilization (IVF), two chemical pregnancies, one ectopic pregnancy, and two miscarriages. The most devastating loss comes at eleven weeks, just as Malcolm had begun choosing baby names. She is passed over for partner at her law firm, partly because treatments caused her to decline work travel, and pivots to a position at a media company called Bloom. She secretly asks her fertility doctor to use a donor egg without Malcolm's knowledge, and the doctor refuses. When she raises donor eggs and adoption openly, Malcolm declines both, saying he considers the two of them a complete family. Jess cannot accept this, and their marriage slides into silence and distance.
At a work conference in San Francisco, Jess nearly has an affair with a stranger but pulls away before anything happens. Back home, she breaks down in front of Malcolm, who holds her and admits he does not know how to fix their problems. She meets Neil at a Memorial Day barbecue at Patrick and Siobhán's house, where he arrives with his three young children; his ex-wife lost primary custody after driving drunk with the children in the car. Jess and Neil's connection builds slowly through texts and charged encounters, culminating in a furtive kiss at a New Year's Eve party. Weeks later, Neil comes to her house while Malcolm is at the bar, and their physical relationship begins.
Jess leaves Malcolm on Halloween. She tries to tell him about Neil, but he interrupts with a petty argument, and the moment passes. She spends seventeen weeks at her college friend Cobie's apartment in Manhattan. Neil, impatient with her reluctance to go public, gets drunk with Patrick and confesses everything.
Back in the present, the blizzard knocks out power. Trapped in his dark house, Malcolm discovers bags of baby clothes Jess stored in the attic. Lying in bed, he realizes Neil has three young children and that Jess's attraction may be partly about the ready-made family she never had. On Sunday, Rob Waggoner, a young police officer and Tripp's son, comes asking about Tripp, who has not been home since Friday. Rob suspects his father planned to disappear, having found research on remote locations and a changed life insurance beneficiary named Mark Duro. Officers later discover evidence that someone was living on the bar's unused second floor. Billy confronts Malcolm at home, demanding payment by the weekend.
Jess, meanwhile, has moved into Neil's house. She bonds with his children but recognizes troubling tendencies in Neil. He tells her he has had a vasectomy, extinguishing her hope that a new relationship might lead to pregnancy. When Malcolm drives to Neil's neighborhood and confronts Jess, she sits in his car and says she does not know if she loves Neil. Malcolm accuses her of seeking a ready-made family; Jess counters by referencing a night she caught him in the kitchen with another woman, a near-infidelity they never discussed. Malcolm apologizes for the first time. Jess tells him she has a plan to solve their financial crisis.
Jess proposes arson. She argues that a fire in the Half Moon's basement, disguised as an accident caused by an old space heater during the power outage, would appear accidental. The fire insurance policy she purchased after discovering Malcolm's side deal with Hugh would produce a payout large enough to clear their debts. That afternoon, they go to the bar, drink Manhattans, and begin staging the scene. Jess lights a match, but the flame dies. As she reaches for a second, Malcolm stays her hand. He thinks of his bartender Emma's cardigan in the broom closet, a colleague's children's photo on the microwave, and a framed photograph of his father standing outside Gephardt's in 1982. He cannot go through with it. They restore everything and leave.
The next morning, federal agents arrive asking about Tripp, whose business partner has been arrested. They show Malcolm a driver's license for Mark Duro, and Malcolm recognizes the photo as Roddy but says nothing. He tracks Roddy to a diner, where Roddy reveals the full scheme: Using his skills in skip tracing, the practice of locating hard-to-find individuals, Roddy built a fabricated identity for Mark Duro. Tripp stayed upstairs at the bar Friday night, was driven to a New Jersey hotel, and flew to Lima on a false passport. The Toronto itinerary and a Panama City apartment were decoys, and a staged accident in Panama using a purchased corpse would produce a death certificate for the insurance claim.
Meanwhile, Jess discovers a legal mechanism to free them from Hugh's debt. Malcolm's mother, Gail Gephardt, tips Jess off after recalling that in the 1970s, Malcolm's father, Darren Gephardt, accepted the land beneath the Half Moon from Hugh to settle a gambling debt. Malcolm and Jess drive through the night to Hugh's home in South Carolina. Jess proposes a deal: Malcolm signs the land over to Hugh, and Hugh takes back the entire property, clearing Malcolm's debt. After a tense exchange, both men agree.
Jess breaks things off with Neil and realizes her feelings for him have evaporated. Malcolm signs over the bar and informs his staff, who are supportive. He learns that Tripp was supposedly killed in a taxi accident in Panama City, but the Feds have doubts. Weeks later, Tripp is captured at a farm in Peru's Sacred Valley, traced through internet café searches for his own name. He is extradited and charged with fraud, money laundering, perjury, and theft. Roddy is never mentioned in the coverage, and Malcolm realizes Roddy has escaped consequences entirely.
Malcolm reconnects with Adrian Walsh, a former colleague who manages a bar on St. John in the U.S. Virgin Islands. Adrian recommends Malcolm as his replacement, and Malcolm is hired with a one-year contract and free housing. Jess is initially skeptical but recognizes they need a fresh start. They put their house on the market and donate the baby items from the attic. On a summer Friday morning, Jess drives Malcolm to the airport. She expresses anxiety about the unknown, and Malcolm tells her that if it does not work out, they simply come home. She holds him tightly, and he kisses the part in her hair before heading inside.