In early September, middle-aged New York City social worker John Morden and his wife, Iris, prepare their two sons for another year at an elite private school they cannot afford. At the welcome-back party, Iris introduces herself to Nina Bishop, the young school psychologist recently arrived from Iowa with her new husband, Chuck Bishop. Wealthy socialite Claire Laurent interrupts the conversation, startling them with bawdy comments about her sex life. Claire explains that she only attended the event as a favor to her husband, toy manufacturer Leo Rothenberg, whose bratty thirteen-year-old daughter, Lucy, attends the school. Despite Claire’s protests, Iris recruits her and Nina for the school pageant decorations committee. Although the Bishops’ apartment is not yet furnished, Nina offers to host the committee’s first dinner party meeting. After an awkward start, the couples discuss the pageant’s 1960s theme. John recalls his youth as a “flower child,” and bonds with Leo about the music and trends of the era. At his job as a Wall Street stockbroker, Chuck aspires to make a good impression on his boss, and gratefully accepts an investment tip from his suave associate, Jeremy Brimfield. One afternoon, Leo fights with his ex-wife, Madeleine, insisting he spoils Lucy with gifts because he was unable to give her a perfect family life after the divorce. Unwilling to put aside her differences with her stepmother, Lucy begins therapy sessions with Nina. Lucy comes to trust Nina, who encourages the girl to make more of an effort to connect with Claire. Leo and Claire host the next committee meeting, and Claire takes pleasure in showing off their lavish décor and serving classy hors d’oeuvres. The couples lose track of time, and Leo suggests they reconvene at the Mordens’ apartment the following week. A few days later, Chuck is arrested for “stock parking,” and the story gains widespread media attention. After he is released on bail, Chuck confronts Jeremy Brimfield, believing Jeremy’s advice led to his arrest. Although Chuck pleas his innocence, he struggles to find an attorney that will take the case to court. Iris refers him to her liberal lawyer friend, Sol Chamberlain, who agrees to represent Chuck despite their political differences. To cover the bills, Nina starts a private psychology practice in her apartment, which adds to Chuck’s stress. One night while Leo is detained at work, Claire sends a limousine to pick up Lucy from a friend’s house. Hoping to get her stepmother into trouble, Lucy gets drunk on whiskey in the limousine’s back-seat bar and instructs the chauffeur to drive her around town. She eventually winds up at the Bishops’ apartment, seeking Nina’s comfort. Nina returns Lucy to Leo, who is relieved to see her home safely and reprimands Claire for being careless. Claire blames Lucy for failing to establish a relationship, but Nina reminds her that Lucy is just a child caught in the middle of her parents’ mistakes. Once upstairs, Claire admits that she does not want to be a mother to Lucy. Leo is unwilling to compromise for his daughter, and the two agree to get a divorce. The news shocks the Mordens and the Bishops, who help Leo move into a new apartment. As the men re-paint the interior, the women spend the afternoon out, and Nina says that she considers Iris and Claire to be close friends. Over time, Nina becomes increasingly frustrated by Chuck’s reclusiveness, but Iris urges her not to give up on the relationship so quickly. Now alone, Leo struggles to connect with his daughter. Lucy blames herself for the dissolution of Leo’s marriage, but Leo insists Claire simply did not know how to be a parent. Nina returns home to find that Chuck has done the chores and prepared dinner. He apologizes for pushing her away, claiming that he wanted to protect her. They reconcile, and Nina helps Chuck and Sol prepare their defense. Meanwhile, Claire loans Iris a revealing dress for John’s black-tie work gala. John is stunned by his dowdy wife’s glamorous transformation, but Iris is hurt by the implication that he is more concerned with physical attraction and does not appreciate everything she does to keep their family together. Sol Chamberlain eventually uncovers evidence revealing that Jeremy Brimsfield used Chuck as a pawn in the stock parking scandal, and Chuck is cleared of all charges. On the night of the school pageant, Claire attends the opera with her new lover. While listening to another snooty socialite speak negatively about marriage, Claire has second thoughts about her decision to walk out on Leo and creates an excuse to leave the theater. Arriving at the school during the final musical number, Claire sits next to Leo in the audience and joins her friends in an enthusiastic round of applause.