The scene opens as usual on the living room at 6:30 pm, just before dinner time. Mary and Cathleen are alone in the room; Cathleen, at Mary's invitation, has been drinking. Although they discuss the fog, it is clear that Cathleen is there only to give Mary a chance to talk to someone. They discuss briefly Tyrone obsession with money, and then Mary refuses to admit to Edmund's consumption. Mary delves into her past memories of her life and family. As a pious Catholic schoolgirl, she says that she never liked the theater; she did not feel "at home" with the theater crowd. Mary then brings up the subject of morphine, which we learn Cathleen gets for her from the local drugstore. Mary is becoming obsessed with her hands, which used to be long and beautiful but have since deteriorated. She mentions that she used to have two dreams: to become a nun and to become a famous professional pianist. These dreams evaporated, however, when she met Tyrone and fell in love. She met Tyrone after seeing him in a play. He was friends with her father, who introduced the two. And she maintains that Tyrone is a good man; in 36 years of marriage, he has had not one extramarital scandal.
Cathleen then exits to see about dinner, and Mary slowly becomes bitter as she recalls more memories. She thinks of her happiness before meeting Tyrone. She thinks that she cannot pray anymore because the Virgin will not listen to a dope fiend. She decides to go upstairs to get more drugs, but before she can do so, Edmund and Tyrone return.
They immediately recognize upon seeing her that she has taken a large dose of morphine. Mary tells them that she is surprised they returned, since it is "more cheerful" uptown. The men are clearly drunk, and in fact Jamie is still uptown seeing whores and drinking. Mary says that Jamie is a "hopeless failure" and warns that he will drag down Edmund with him out of jealousy. Mary talks more about the bad memories from the past, and Tyrone laments that he even bothered to come home to his dope addict of a wife. Tyrone decides to pay no attention to her. Mary meanwhile waxes about Jamie, who she thinks was very smart until he started drinking. Mary blames Jamie's drinking on Tyrone, calling the Irish stupid drunks, a comment which Tyrone ignores.
Mary's tone suddenly changes as she reminisces about meeting Tyrone. Tyrone then begins to cry as he thinks back on the memories, and he tells his wife that he loves her. Mary responds, "I love you dear, in spite of everything." But she regrets marrying him because he drinks so much. Mary says she will not forget, but she will try to forgive. She mentions that she was spoiled terribly by her father, and that spoiling made her a bad wife. Tyrone takes a drink, but seeing the bottle has been watered down by his sons trying to fool him into believing that they haven't been drinking, he goes to get a new one. Mary again calls him stingy, but she excuses him to Edmund, telling of how he was abandoned by his father and forced to work at age 10.
Edmund then tells Mary that he has tuberculosis, and Mary immediately begins discrediting Doc Hardy. She will not believe it, and she does not want Edmund to go to a sanatorium. She thinks that Edmund is just blowing things out of the water in an effort to get more attention. Edmund reminds Mary that her own father died of tuberculosis, then comments that it is difficult having a "dope fiend for a mother." He exits, laving Mary alone. She says aloud that she needs more morphine, and she admits that she secretly hopes to overdose and die, but she cannot intentionally do so because the Virgin could never forgive suicide. Tyrone reenters with more whiskey, noting that Jamie could not pick the lock to his liquor cabinet. Mary suddenly bursts out that Edmund will die, but Tyrone assures her that he will be cured in six months. Mary thinks that Edmund hated her because she is a dope fiend. Tyrone comforts her, and Mary once again blames herself for giving birth. Cathleen announces dinner. Mary says she is not hungry and goes to bed. Tyrone knows that she is really going for more drugs.
Notice that, as mentioned in previous sections, the play is structured around either waiting for meals or recovering from them. In this case, the family is biding time waiting for dinner to be served. However, the process of having meals together breaks down over the course of the day. Breakfast goes smoothly, but then lunch is stalled for a long time as the family waits for Tyrone to return from the garden. Dinner itself is a disaster; Jamie is not even home from carousing, and Mary does not attend because she has lost her appetite as she takes more drugs. The central activity of the family eating together has fallen apart as the day has gone on.