One evening in 1937, fourteen-year-old Eugene Morton, fantasizes about being a baseball player outside his New York home. His mother, Kate, is inside with her younger widowed sister, Blanche. Kate calls Eugene inside to do chores, but Laurie, Blanche’s thirteen-year-old daughter, doesn’t have to help because she has a weak heart. Directly addressing the audience, Eugene explains that the two families share a house because Blanche’s health prevents her from getting a job. Eugene’s father, Jack, is the primary breadwinner. As they set the table, Nora, Blanche’s sixteen-year-old daughter, runs in with exciting news: She has been offered a job as a dancer in a Broadway musical. Nora wants a future on the stage but also to earn money for her family. Blanche, unable to decide if Nora should quit high school for this opportunity, decides to leave the decision to Jack. Nora storms to her room and wishes her father was still alive. She and Laurie vow to save money for their own home. 

Downstairs, Eugene’s eighteen-year-old brother Stanley returns from his job. He’s worked full-time since graduating high school. He confides in Eugene that he stood up to his boss for treating another employee unfairly. Now Stanley will be fired unless he apologizes. Stanley wants to stick to his principles and not write the letter but will talk to his father first.

Soon, Jack comes home from one of his jobs. The company has declared bankruptcy, and Jack got sent home without his much-needed week’s pay. At dinner, no one talks about these serious issues, and afterward, Jack listens to the radio for news about Europe, where they have Jewish relatives. Eugene and Stanley go to the bedroom they share, where Stanley explains about masturbation while Eugene confesses to a crush on Nora. Meanwhile, Nora interrupts Jack to tell him about her audition. While Jack and Nora take a walk, Blanche and Kate discuss an upcoming party that Kate wants Blanche to attend. Kate hopes Blanche will meet a nice man, but Blanche already has a date with their Irish neighbor, Mr. Murphy. Kate worries he may be a drinker. 

Eventually, Nora and Jack return, and Blanche agrees with Jack that Nora should stay in school and skip the audition. Kate wants Jack to get some rest, but Stanley is still waiting to talk with him. He explains the choice he faces about his job. While Jack agrees about the importance of principles, he expresses concern that the family can’t afford them right now. Stanley returns to his bedroom, and Eugene offers to help write the apology.

One week later, Eugene tells the audience Jack has suffered a minor heart attack. In their room, Stanley confesses to Eugene that he lost his salary gambling. The brothers, nervous about their father and about money, briefly quarrel. Meanwhile, Jack disregards the doctor’s orders to stay in bed and comes downstairs, worrying Kate. Nora, who is still angry about the audition, rushes out of the house before Blanche comes down for her date. Kate goes to the boys’ bedroom to get money for Blanche, and Stanley admits what happened. She cautions him not to tell Jack. They will figure out what to do without bothering him.

Blanche can tell Kate is upset when she comes downstairs again, but Kate won’t say what’s wrong. Then Laurie enters with a letter from Mr. Murphy’s mother. He had a drunken car accident and must cancel the date. In the ensuing discussion, Kate and Blanche end up arguing. Kate says that she feels like she has been taking care of everyone her whole life, and now her husband is sick from taking care of Blanche’s family. Blanche is shocked and disturbed at Kate’s anger. She decides to move out and get a job. Blanche asks to leave the girls until she is settled. 

Meanwhile, Stanley is about to strike out on his own. He believes he is at fault for breaking up the family and he will join the Army to earn money. Later that evening, Eugene and Laurie discuss Stanley’s departure and Blanche’s impending move. During this talk, Eugene suggests that Blanche might be exaggerating Laurie’s heart flutter to keep her close by.

When Nora returns late that night, Blanche shares her plans to move. Nora is angry that her mother is leaving when she was not allowed to leave her mother. She reveals that she is jealous that Laurie gets so much attention because of her heart condition and has always felt unloved. Blanche denies Nora’s accusations.

Kate and Blanche finally talk. Blanche explains that she realizes she must be independent, for herself and her daughters. They agree that Blanche, Nora, and Laurie will stay in the house until Blanche finds a job. 

The next day, Stanley returns. He realized his family needed him more than they needed money. Jack forgives Stanley for leaving in secret and says he’s a good son. Just before dinner, Jack enters the room reading a letter from a Jewish cousin whose family escaped Poland and is arriving in America. Everyone agrees to open the house to their family. Eugene addresses the audience and tells them that puberty is now over for him.