On a late October evening in 1977, Nina Larkin hosts a birthday dinner for her husband, Sam. The party is smaller than planned, as several guests have canceled due to illness. The only attendees are their neighbors from across the street, Honey and Finn Finnegan, and Bess, who is newly divorced. The atmosphere is strained. Bess becomes drunk and combative, launching into a rant about Richard Nixon. Nina reflects on how these neighborhood dinner parties, once a welcome escape, now feel stale and repetitive.

Upstairs, Nina and Sam’s 17-year-old daughter, Clara, tries to imagine she’s constantly being filmed, which helps her maintain her poise. She’s thrilled with her recently developed breasts, a change she sees as miraculous. After a brief, coded phone call with Finn and Honey’s son, Dune, she decides to make an appearance at the dinner party. She puts on one of her mother’s tops, applies makeup, and heads downstairs, feeling confident and grown-up.

Clara’s arrival at the dinner party causes a stir. Bess greets her enthusiastically, and in the process, her wraparound skirt comes undone, revealing a leotard underneath. The conversation shifts to Sam’s work at Xerox, where he has recently attended a conference demonstrating new personal computers. The guests are intrigued by a feature called “universal undo,” which allows users to reverse any action. Nina, weary of the party and annoyed with Sam, uses Clara’s presence as an excuse to end the night. She asks Clara to help her clear the table in the kitchen.

Nina’s younger daughter, Bridie, is anxious about the possibility of her parents getting divorced, a fear heightened since Bess’s marriage ended. Bridie’s fears have turned her into a snoop, constantly watching her parents for signs of trouble. While pulling handbags down from a shelf in her mother’s closet, a book tumbles down and hits her on the head. She’s shocked to discover it is The Joy of Sex: A Gourmet Guide to Love Making.

Bridie takes The Joy of Sex to Clara, who is amused and intrigued. They sit on Clara’s bed, laughing at the book’s illustrations and chapter headings like “Mouth Music.” They speculate on whether their mother or father bought it, but Clara rules out both parents. The shared, illicit discovery creates a rare moment of closeness and fun between the two sisters.

The next day, the Larkin family has a lunch of leftovers from the party. Sam is in a sour mood, which only lifts when Clara presents a potato dish she made especially for him. After Sam leaves for the office, Nina anxiously watches for Finn to leave a book in her mailbox, wanting to retrieve it before Sam returns. She and Finn are having an affair. As prearranged, Finn walks across the street and places a book containing a thick manila envelope into their mailbox, a signal for Nina.

Finn recalls meeting his wife, Honey, and their subsequent courtship, which has led to a passionless and dutiful marriage. His reflects that his dissatisfaction intensified after he suffered a major heart attack, which made him feel a new urgency to live authentically. The affair with Nina began the previous spring at the Finnegans’ lake house: Nina had been watching Finn for weeks and followed him to the boathouse during a rainstorm. Finn had unbuttoned her blouse and initiated their physical encounter. Now, months later, Finn is resolved to divorce Honey and build a new life with Nina.

Finn and Honey’s daughter, Fern, is intensely self-conscious about her stutter. It causes her significant anxiety, particularly when she has to read aloud in her French class, where other girls mock her. Her family avoids discussing the issue, leaving Fern to manage her struggles alone.

Honey is a devout Weight Watchers meeting leader, obsessed with helping others feel confident. She believes Fern’s stutter is linked to her weight and would improve if she lost a few pounds. She strikes a deal with her daughter: She will look into getting Fern a speech therapist if Fern agrees to attend Weight Watchers meetings with her. Fern reluctantly agrees. Finn arrives home as they are shaking on the deal.

Finn recalls the morning of his heart attack, the day after his 52nd birthday—the age at which his own father died of a coronary. While shoveling snow, he collapsed. He remembers that he felt he was floating above his body and had to choose between staying with his deceased mother or returning to his daughter, Fern, who was sobbing over him. The experience convinced him that he could no longer remain in his unfulfilling marriage to Honey.

Clara strategizes how to win the affection of Dune, who has transformed over the summer into a handsome young man. She is jealous of his budding romance with a popular girl named Greta. Clara’s new drama teacher, Mr. Goodwin, is directing the school musical, Godspell, and she decides to ask Dune to be her audition partner. She believes that working closely together will make him fall for her.

Dune feels conflicted about his long-standing habit of spying on the Larkin sisters in their bathroom with a pair of toy binoculars. Now that he and Clara are growing closer romantically, the peeping feels wrong, and he resolves to stop. Before throwing the binoculars away, he takes one last look. He sees his father, Finn, walk across the street and place a book and a large manila envelope into the Larkins’ mailbox. He thinks about investigating to see what’s in the envelope, but then Clara emerges, heading over to his house for their rehearsal.

Nina reflects on her life before Sam. Her first engagement ended when her high school sweetheart Patrick left her on their wedding day. Wanting a fresh start, she moved from Manhattan to Rochester for a job at an advertising agency, where she met Sam, but their marriage has always lacked passion. In the present, Nina feels pressured by Finn’s desire to end their respective marriages, but after breaking things off with him weeks earlier, she feels miserable. She retrieves the package Finn left in the mailbox and discovers it contains airline tickets to the Dominican Republic. He wants them to get quick divorces so they can marry each other.

During their Godspell rehearsal, Clara and Dune disagree on an audition song. She suggests the more somber “Send in the Clowns,” while he wants to perform something unexpected. They compromise, and the tension between them dissolves into flirtation. The rehearsal ends with a passionate make-out session on Dune’s bed.

Late one night, Sam comes home extremely drunk, supported by a handsome young coworker named Garret, who works on the development side at Xerox’s Palo Alto Research Center (PARC). Nina has never seen Sam in this state and is unsettled. As Garret leaves, he gets into a distinctive pickup truck that Nina recognizes. The driver is Margaret, Nina’s old friend and former landlady, who inherited a bar downtown and made it a welcoming space for gay patrons. The encounter leaves Nina suspicious about the nature of Sam’s relationships.

In early December, Nina chaperones Bridie’s French class on a trip to the local art gallery. She has been feeling unwell since attempting to end her affair with Finn. At the gallery, she’s deeply moved by Claude Monet’s painting Waterloo Bridge: Veiled Sun. The painting’s depiction of beauty emerging from a gloomy landscape connects with her own feelings of being trapped. In a moment of quiet rebellion, when she is alone in the gallery, she steps past the security line and touches the surface of the canvas, an act of transgression that solidifies her resolve.

Very early one morning, Fern is awakened by a noise. From the bathroom window, she sees Nina walk across the street with a suitcase and get into her father’s car. She watches in horror as her father kisses Nina before they drive away. Fern runs outside barefoot into the snow, trying to get their attention, but her father drives away without noticing her.

Clara comes downstairs to find the kitchen empty, and a note from her mother propped on the table. The letter explains that she has left with Mr. Finnegan and will return on Saturday. Clara is stunned and walks into the living room in a daze, where she is met by her father. She hands him the note.

On the flight to Santo Domingo, Nina is consumed by guilt, replaying the image of Fern running outside into the snow. Finn, however, is cheerful and optimistic. Upon arriving in the Caribbean, Nina feels overwhelmed by the heat and the unreality of the situation. Finn has filled their hotel room with roses and wants to take pictures to commemorate the start of their new life. The first photo captures Nina looking more like a hostage than a happy bride-to-be.

Sam reflects on his lifelong struggle as a closeted gay man. He has always hidden his true identity to meet the expectations of his family and his corporate career at Xerox. His marriage to Nina was an attempt to lead a conventional life, while his desires were relegated to furtive, shame-filled encounters with other men. His recent, more emotionally involved relationship with his coworker Garret has threatened this carefully constructed facade. Nina’s departure has left him feeling both exposed and trapped.

Honey wakes up to find Finn gone and a note on the kitchen table. Her daughter Fern, who witnessed their departure, is sitting in the dark, wrapped in a blanket. Honey recalls her final, fraught conversations with Finn, in which he told her he was unhappy in their marriage, and she responded with threats of religious and social damnation. She reflects that being sexually assaulted by her cousin when she was a teenager left her with a deep-seated fear of intimacy, which contributed to the breakdown of her marriage. Stunned and lost, Honey impulsively decides to take the children to their lake house.

At Finnegan’s Grocer, Finn’s second-in-command, Helen, recalls his recent confession about leaving Honey for Nina. Before he left, Finn gave Helen his contact information for emergencies. Shortly after he departs, a deli employee, Robert, leaves a note on Finn’s office door warning that one of the new refrigerators is making a strange noise.

In Santo Domingo, Nina feels alienated and out of place. At the hotel pool, she befriends another woman, Judith, who is also there to finalize a divorce. On Thursday, Nina and Finn go to the courthouse, and their respective divorces are granted. That afternoon at the beach, they have intensely passionate sex in a changing cabana, a moment that Nina feels solidifies their union. The next morning, they are married in a brief ceremony, with Judith acting as their photographer.

Back in Rochester, the malfunctioning refrigerator at Finnegan’s Grocer fails. The temperature rises, causing a batch of roast beef to spoil. Unaware of the spoilage, Robert prepares dozens of “beef on weck” (117) sandwiches, which are distributed to three store locations. He also sets out free samples, which are consumed by numerous customers and employees throughout the day.

Helen is forced to manage a rapidly escalating public health crisis as customers and employees fall ill with salmonella poisoning from the contaminated beef. The situation worsens when Robert’s elderly grandmother is hospitalized in intensive care as a result of the food poisoning. Finn’s uncle, Dennis, whom Finn had previously forced into retirement, sees the scandal as an opportunity to regain power. Dennis suggests to Helen that leaking the story of Finn’s elopement to the press will distract public attention from the salmonella scandal, and Helen makes the calls to the press.

Clara and Bridie struggle to get through the school week. At lunch on Friday, a cruel classmate shows Clara an item in the newspaper’s society column announcing her mother’s marriage to Finn. Humiliated and furious, Clara goes home and begins a frantic campaign of cleaning and cooking, using domestic order to cope with her emotional chaos.

Upon landing in Rochester, Finn and Nina are met with the news of the dual scandals. A newspaper headline details the salmonella outbreak at Finnegan’s Grocer, and the society page reports on their elopement. They drive to their temporary rental house—the start of their new life already mired in crisis. The local Finnegan’s is closed, forcing Nina to shop at a competitor’s supermarket for the first time.

When school resumes after the winter break, the director of the school play, Mr. Goodwin, informs Clara that Dune has threatened to quit Godspell if he is forced to perform alongside her. Goodwin tells Clara he tried to talk Dune into being more accommodating, and offers to recast Dune if Clara wants to stay. Feeling the situation is untenable, Clara agrees to drop out of the play. Afterward, in the school parking lot, she sees Dune waiting in his car and thinks he wants to talk. As she approaches, he speeds away without acknowledging her.

Robert’s grandmother, Concetta, dies from complications of salmonella poisoning. The death provides the Finnegan’s Grocer board with the justification to oust Finn. Led by Dennis, the board forces Finn to step down as president. To ensure his son Dune’s future at the company, Finn accepts a reduced, powerless role as head of the Finnegan Community Foundation. Dennis and Helen now effectively run the company.

In the months following the elopement, Clara channels her rage into perfecting her cooking and maintaining control over the household. She refuses to see or speak to Nina. She confronts Dune one last time, declaring her love for him, but he rejects her, blaming Nina for ruining his life. Devastated, Clara realizes their relationship is over and that he cannot separate her from her mother’s actions.

Fern finds a surprising sense of community at her mother’s Weight Watchers meetings. A classmate, Jenny, introduces her to amphetamine diet drops, which she calls “pep juice.” The drops suppress her appetite, leading to rapid weight loss and thrilling her mother. Fern’s friend, Phoebe, warns her of the dangers of the Dexatrim, noting that the drugs cause insomnia. One night Fern finds her brother, Dune, drinking heavily, claiming he’s fulfilling his new role as “man of the house.”

Dune is deeply unhappy. He feels burdened by his mother’s expectations and miserable performing in Godspell with his replacement co-star, Deirdre. His drinking escalates to help him cope with his anger and loss. He begins dating Greta again, but the relationship is strained. One night, he throws the withered gardenia corsage out his window that he had bought for Clara for the New Year’s formal they never attended.

Sam feels trapped by Nina’s departure. Instead of feeling liberated, he is now subject to social pressure to start dating women again. Garret pushes him to be more open about his sexuality, but Sam is terrified of losing his job at Xerox and causing his daughters more pain. His anxiety spikes when he comes home from work to find Garret has dropped by unannounced and is charming Clara and Bridie in the kitchen.

Finn and Nina’s new life is one of social isolation. Finn is shunned at church, and a cooking class Nina planned to teach is boycotted. Weighed down by their circumstances, Nina loses her passion for cooking. Her greatest source of pain is Clara’s continued hostility. Clara refuses to let Nina into their old house and controls Bridie’s visits to Nina and Finn’s new house, creating a painful rift between Nina and both of her daughters.

When Clara falls ill, Nina sees an opportunity for a truce. She arrives at her old house with a car full of groceries and comfort foods. She finds the kitchen has been completely rearranged and reorganized by Clara. They have a tense and painful confrontation in which Clara reveals the personal cost of the elopement: Her breakup with Dune and her decision to quit the school play. Clara also announces that she has deferred her admission to Cornell to stay home and look after Bridie. Stunned and worried by Clara’s act of self-sabotage, Nina lashes out, and Clara tells her to leave. Nina realizes Clara’s obsessive cooking and household management is not just a coping mechanism but a “coup”—a deliberate and successful attempt to replace her in the family.