In 1986, in Brooklyn, New York, a Berkman family tennis game ends unpleasantly when Bernard, a noted author and professor, lobs a powerful ball that hits his wife, Joan. Joan stalks angrily off the court, stung by the ball and Bernard’s aggressive behavior. The next morning, their twelve-year-old son Frank discovers that Bernard spent the night on the sofa bed. Although Frank adores his mother, his sixteen-year-old brother Walt admires Bernard, and dismisses as amateur Joan’s recent work as a writer. Bernard, who values intellect above any other quality, brings Walt to a university writing class he teaches, where Walt is exposed to a sexually explicit story written by a seductive twenty-four-year-old student, Lili. While driving home, Bernard hails Lili’s story as risky, post-modern writing and urges Walt to read the work of Franz Kafka, whom Bernard champions as his own literary predecessor. Bernard and Walt bond further after seeing Joan talking intimately with an unfamiliar man on the street; Bernard becomes suspicious and Walt’s contempt for his mother deepens. Following a particularly nasty argument, Bernard and Joan announce they are getting a divorce and that the boys, and their cat, will evenly split their time between two homes. Both boys are distraught, but Walt blames his mother for the split. When Bernard introduces the boys to his ramshackle new house, which he describes as “elegant,” it is evident he has given little thought to their tastes or comfort. Tension flares between the boys after Frank complains about the house and defends Joan, and a resentful Walt briefly and painfully pins Frank to the floor. Walt’s resentment toward Joan is vindicated when Bernard reveals that Joan has been having affairs for years, although Bernard believes she left him because his recent work has been unsuccessful. Despite Joan’s attempt to discuss the matter with her son, Walt refuses to continue staying with her. Meanwhile, Frank’s behavior has deteriorated: he is secretly obsessed with sex, drinks beer and after masturbating in the school library, spreads his semen on a bookshelf. Walt’s days are complicated by the discovery that his mother once slept with his friend Otto’s father. At the same time, Walt, who ignorantly parrots what his father says about books and writers, becomes involved with his first girl friend, Sophie Greenberg. Bernard, already parsimonious and insensitive, becomes more self-absorbed than ever after receiving a rejection letter from a publisher. He shows little interest when Frank is sick, and insists on playing an overly competitive ping-pong game with him, during which Bernard advises Frank, who aspires to be a tennis pro like his teacher Ivan, that he is in danger of becoming a philistine. One evening, Walt witnesses the warmth of a normal family when Sophie invites him to dinner with her family. However, familial normalcy slips even farther from Walt’s grasp after Bernard invites Lili, on whom Walt has a mild crush, to rent a room in his house. Bernard further fails both his sons in one night by leaving Frank alone at home while he takes Walt and Sophie to see Blue Velvet , an embarrassingly sexually perverse film, after which Bernard accepts Sophie’s money to help pay for dinner. Frank runs to his mother’s house and discovers she is having an affair with Ivan, whom he idolizes. Soon after, Bernard and Lili start having an affair, while on the same night, Walt and Sophie, both virgins, begin exploring sex. When Walt later wins a prize at the school talent contest by playing a Pink Floyd song that he claims he wrote, his parents, unaware that the song was plagiarized, are proud of his apparent achievement. Nevertheless, Walt is so insulting to Joan that she slaps him. Bernard also receives a blow when, over dinner, Lili tells him that an excerpt from Joan’s soon-to-be published novel has appeared in The New Yorker magazine. After dinner, a confused Walt lashes out at Sophie and ends their relationship. Some time later, Joan and Ivan go out of town, expecting that Bernard will pick up Frank for the weekend, but Bernard forgets about him and takes Walt and Lili to State University of New York at Binghamton, where he speaks at a poorly attended reading. Completely forgotten, Frank lays out his mother’s lingerie, plays with some condoms and throws up after getting drunk. Joan and Bernard soon must confront how deeply their divorce has affected their sons after the principals at both schools call them in for conferences; one about Frank’s masturbation and the other concerning Walt’s musical deceit. Each parent blames the other. However, Bernard reluctantly agrees for Walt to see a school therapist, who helps Walt finally to comprehend how much he misses his mother by prodding him to fondly recall their special closeness when he was a boy, particularly when she would quell his fear about an exhibit of a squid and a whale locked in combat at the American Museum of Natural History. His father, notably, was always absent. Walt returns to Bernard’s house, but after encountering Bernard attempting to force himself on Lili, Walt leaves and wanders the neighborhood alone. He eventually goes to see Joan, and after admitting his regret about breaking up with Sophie, they have an honest discussion. They are interrupted by Bernard, who makes a disingenuous offer at reconciliation, which Joan responds to with laughter. When Bernard angrily vows to fight for full custody, Joan claims he only wanted partial custody because it is less expensive than paying full child support. A stunned Walt reluctantly agrees to return to Bernard’s house after Frank refuses to go back, and Frank sweetly offers Walt temporary custody of their cat. However, the cat leaps out of Walt’s arms and hides under a parked car. Bernard tries to grab him, but is distracted by a police officer ticketing his double-parked auto, and the cat escapes again. Ivan arrives just as Bernard collapses from an apparent heart attack and Ivan and Walt ride with Bernard when he is taken away in an ambulance. In the morning, Bernard tells Walt that he collapsed from exhaustion, not a heart attack. When Walt reveals he does not want to return to Bernard’s house, Bernard admits he is hurt and insists that Walt has no choice in the matter. Bernard attempts to cajole Walt, and although they share a warm moment, a distrusting Walt abandons his father at the hospital without saying goodbye. Walt then runs to the Museum of Natural History, where he gazes intently at the squid and whale exhibit.