The film is about two couples: Jack (Pollack) and Sally (Davis), and Gabe (Allen) and Judy (Farrow). Gabe is an English professor at a college, Judy works at a magazine, Jack is a businessman, and Sally is a co-worker. The film starts when Jack and Sally arrive at Gabe and Judy’s apartment and announce their separation. Gabe is shocked, but Judy takes the news personally and is very hurt. Still confused, they go out for dinner at a Chinese restaurant.
Later that night, Judy asks Gabe if he ever fantasizes about other women. Gabe brushes her questions off, and they go to bed. The next day, Gabe approaches Rain, a student of his whom he admires for her brilliant writing. Rain and Gabe go out for a walk while discussing her writing.
That night, Sally goes to the apartment of a colleague. They plan to go out together to the opera and then to dinner. Sally asks if she can use his phone, and calls Jack. Learning from him that he has met someone, she accuses him of having had an affair during their marriage.
Shortly after, Gabe, Judy and Sally are out walking when they spot Jack with a blonde woman in her late twenties. Sally hastily departs, dropping her purse and its contents while climbing into a taxi. Judy and Gabe are introduced to Jack’s new girlfriend, Sam, an aerobics trainer.
While Judy and Sam shop, Gabe tells Jack that his new girlfriend is a ‘cocktail waitress’ and tells him that he is crazy for leaving Sally for her. About a week later, Judy introduces Sally to Michael (Neeson), Judy’s magazine colleague. Michael asks Sally out.
Later, at a party, Jack is embarassed when Sam defends astrology to several guests, and they get into a heated debate. Jack drags Sam away and she becomes upset and hysterical. Jack aggressively shoves her into the car. While trying to drive away Jack accidentally hits two cars. Sam gets out and screams, and again, Jack grabs her back into the car.
Cut to Michael and Sally, who are having sex. It then cuts to her talking to an analyst. She then discusses her feelings about which people are hedgehogs are which are foxes. Cut back to Michael and Sally who are discussing their sex. She said that they had two separate but nice experiences.
Jack goes to Sally’s house, where he finds her with Michael. Jack bursts in and begins arguing with Sally and Michael. She tells Michael to go upstairs. Jack accuses her of sleeping with Michael in “their” bed. Later, Jack tells her that he wants to get back with her. The doorbell rings and it is Sam, who Jack has left in the car. After some argument, she demands Jack and Sam to leave.
Meanwhile, Gabe has developed a friendship with Rain and has her read the manuscript for his working novel. She comments on its brilliance, though has several criticisms, to which Gabe becomes defensive due to its pseudo-autobiographical nature of relationships and the trivializing of affairs. At dinner, she reaches for his manuscript (his only copy) only to realize she had left it in a cab. Then a cabdriver finds the manuscript. Rain says that leaving the manuscript was somehow Freudian because she doesn’t like competition. He says he doesn’t need maturity lessons from a 20-year-old twit. They arrive at the cab driver’s house where the driver says that Gabe has a beautiful daughter.
Less than two weeks later, Jack and Sally are back together and the couple meet Judy and Gabe for dinner like old times. After dinner, Judy and Gabe get into an argument about her not sharing her poetry with him, then argue about many things. (This narrative strand was used by Allen’s idol, Ingmar Bergman, in one of his most famous and acclaimed films, Scenes From a Marriage. Allen reverses it, however, as in Bergman’s film, Johan, won’t show his poetry to his wife, Marianne, whereas Judy won’t show her poetry to her husband, Gabe.) During a quiet moment Gabe suggests sex, she says “You always get sexual at the oddest times.” He tries to touch her again. Sitting on the couch, she tells him that she thinks the relationship was over, a week later Gabe moves out.
Judy helps Michael to get over Sally by spending time with him.
At Rain’s twenty-first birthday party hosted by Rain’s parents (Blythe Danner stars as her mother), the lights go out because of a storm, and Rain asks for a “birthday kiss.” Illuminated by the lightning, Gabe and Rain have a romantic moment, but afterward he tells her he cannot pursue it and leaves.
Michael tells Judy that he needs time alone. Then he told her that he couldn’t help still having feelings for Sally. Judy becomes frustrated with Michael and walks out into the rain. Highlighting her “passive aggressiveness,” Michael follows and begs her to stay with him. A year and a half later they marry.
At the end, we see a pensive Jack and Sally back together envying Judy and Gabe, who are ironically not together. Jack and Sally admit their marital problems will exist (ie. her frigidity is not solved), but they find they accept their problems as simply the price they have to pay to remain together.
Gabe is living alone because he says he’s out of the race and doesn’t want to hurt anyone. He said that he realized how much how he messed up with his relationship with Judy. The film ends with an immediate cut to black after Gabe pleads with the unseen documentary crew, “Can I go? Is this over?”