In Los Angeles, city construction worker Nick Longhetti, frets about telling his wife Mabel that he has been forced to work an additional late shift when the couple had planned to spend the weekend together. Meanwhile, Mabel excitedly prepares their young children, Tony, Angelo and Maria, to spend the weekend with her mother, Martha Mortensen. Later, Mabel dresses and waits for Nick at home, while he confides in one of his fellow workers, that he worries about his delicate and unusual wife and is frequently unsure how she will behave. Finally gathering the nerve to telephone Mabel several hours after he was expected home, Nick apologizes profusely and insists they will have the next day to themselves. Disappointed and a little high from having had a drink, Mabel wanders to a nearby bar where she flirts with smalltime businessman Garson Cross. After another strong drink, the dazed Mabel agrees to take Garson home. However, once there, Mabel grows agitated by Garson’s attempts at intimacy and knocks him down. Eventually, though, she allows him to spend the night. The next morning, Garson amiably attempts to chat with Mabel, but now anxious and short tempered, she sends him away. Soon after, Nick arrives home with his entire work crew and invites them to a meal of spaghetti. Despite Mabel having met several of the men before, she politely asks each his name as if they were strangers. When one of the men begins singing a bit of opera and another takes it up, Mabel is delighted and wants to dance, embarrassing Nick, who shouts at her in anger. Later, a phone call from Nick’s mother Margaret interrupts, prompting the men to leave. Afterward, Mabel tells Nick that she only wanted to make his friends feel welcome and comfortable. Although Nick remains angry, he assures Mabel that she did nothing wrong. When Mabel pleads with Nick to tell her what and how she should be, he offers no response. The following morning, Martha brings the children home, and Nick insists on teaching them to whistle before they leave for school. Afterward, Mabel grows increasingly annoyed as Nick repeatedly asks her if she will be all right while he is at work and demands to know if he thinks she is “wacko.” Mabel then spends the day anxiously waiting for the children to return from school. After walking them home from the bus stop, Mabel sits on the porch with them, saying earnestly that the only thing she has ever done with her life is to create them. When she tentatively asks if they consider her to be weird or “dopey,” Tony assures her that she is smart, pretty and nervous. Spotting some of the children’s friends approaching with their father, Mabel makes a game of darting into the house with her children and hiding. The man, Harold Jensen, brings his children to play with the Longhetti children, but when Mabel insists that he stay, then encourages the children to dance to Swan Lake which is on the radio, Jensen grows uncomfortable. After Nick telephones and hears Mabel’s effusive description of the impromptu party, he hangs up. Deciding the children should dress up in costume, Mabel helps them change into various disguises, then returns to the yard to continue dancing with them. Discomfited by Mabel’s insistence that he join her, Jensen admits he is uneasy about leaving his children with her and orders them to change out of their costumes just as Nick arrives with his mother. Shocked when Maria dashes by naked, Nick immediately turns on the hapless Jensen. When Mabel defends Jensen, Nick slaps her and attacks Jensen until Margaret intervenes. After Jensen and his children depart, Margaret puts her grandchildren to bed, while Nick heatedly tells Mabel that she is going to be committed until she gets better. Disregarding this, Mabel forgives him for slapping her and says she understands that Nick was only embarrassed and unsure how to respond. Annoyed, Nick declares that he does not know who she is any more, which dismays, then angers Mabel. Moments later, the family physician, Dr. Zepp, arrives, further alarming Mabel. As Margaret blames her for drinking and being irrational, Mabel accuses Nick of a conspiracy, but he insists that Zepp is only making a social call. When Nick declares that he loves Mabel, Margaret shrilly accuses her daughter-in-law of being an unfit mother and wife. After Nick orders Margaret upstairs, the stunned Mabel says that she has several good points, but when she realizes Zepp is planning to give her a tranquilizing shot she grows hysterical, begging not to be hospitalized before rushing upstairs to the children. Zepp and Nick follow, and Zepp announces that he has the paperwork to have Mabel committed. Over the next six months, while Mabel is hospitalized, Nick remains tense and belligerent at work, refusing to discuss his situation, even when his friends offer sympathy. Feeling guilty about his children, who miss their mother, Nick abruptly takes them out of school one afternoon to go to the beach, where he orders them to have fun. On the way home, while allowing each to have small sips of beer, Nick apologizes to them for sending Mabel away. The day of Mabel’s return, Nick excitedly rounds up dozens of his and Mabel’s friends and family to welcome her back, but when one of Mabel’s friends suggests that the party is excessive and might distress her, Nick abruptly orders everyone to depart except his mother and Dr. Zepp. Mabel’s parents, Martha and George, bring her home, where she greets the children and, after some awkwardness, settles down quietly. Disturbed, Nick pulls Mabel aside to the stairwell to privately assure her that she must be herself and insist that she resume her free-spirited manner. Urging everyone to sit at the dinner table, Nick then asks Mabel to describe her hospital experience, but she demurs, prompting Nick to agree that the only thing that matters is having a good time in the present. When Mabel thanks everyone for coming, then abruptly asks them to leave as she and Nick want to go to bed, her parents become anxious. After Mabel tells a silly joke, however, the ill-tempered Nick demands that only serious conversation be allowed at the table and insists that Mabel relate her experience. Mabel complies, but when she relates undergoing electro-shock therapy and the family recoils, Nick orders her to continue. Mabel turns to her father and quietly asks him to stand up for her against Nick’s callousness. Misunderstanding, George stands up from his chair, then admits that he does not understand his daughter. When Mabel retreats to the living room in tears, a confused Nick follows, but reacts furiously when she begins singing softly. After the distressed family members leave, Nick orders Mabel off the sofa and she flees to the bathroom, followed by her husband and anxious children. Frightened when Mabel grabs a razor blade and badly cuts her hand, the children begin crying and screaming, further agitating Nick, who drags them upstairs, only to have them break away from him and run back to their mother. Outraged, Nick follows, vowing to kill Mabel and the children, but when he again takes the hysterical children upstairs, they rush back to Mabel. Abruptly calm, Nick tells Mabel that the children need to know that she is all right. Mabel hugs her children and calmly guides them upstairs to bed where she has a private word with each. Nick and Mabel then return downstairs, and as Nick bathes and bandages her hand, Mabel wonders if she is crazy and how the situation got so far out of control. The couple then begins tidying up the dining room together.