It is morning in the Tyrones’ summer home when the play begins. James Tyrone—an aging matinee star—is spending time with his wife, Mary, who has recently returned from a sanatorium. James expresses his happiness at Mary being back and encourages her to “keep up the good work.” Mary appears restless, admitting she got little sleep the night before because of a nearby foghorn that blared until morning.
Before long, James and Mary’s eldest son, Jamie, enters. He’s thirty-three and good-looking but “lacks his father’s vitality,” since “the signs of premature disintegration are on him.” His little brother, Edmund, also enters. He is ten years younger, thinner, and looks sickly. Once the two brothers settle in, the family bickers in a way that fluctuates between playfulness and flat-out scorn, especially when James accuses his sons of making fun of him behind his back. After arguing, Edmund gets up and leaves the room, exhausted by the way his father berates him and Jamie for having no work ethic. After he leaves, Mary says that James should go easy on Edmund, since the young man has a “summer cold.” “It’s not just a cold he’s got,” Jamie interjects. “The Kid is damned sick.” Spinning to face him, Mary responds, “Why do you say that? It is just a cold! Anyone can tell that! You always imagine things!”
Jumping in, James suggests Mary shouldn’t worry, maintaining that Jamie simply meant that Edmund might have a “touch of something else, too, which makes his cold worse.” He then says Doctor Hardy thinks Edmund might have caught “malarial fever” from working in “the tropics,” but Mary disregards this, saying Doctor Hardy is unreliable because he’s cheap.
When Mary leaves, James chastises Jamie for talking about Edmund’s health in front of her, saying this is the one topic he should avoid in her presence. The two men then admit to one another that they think Edmund has consumption, at which point Jamie suggests that his little brother wouldn’t ever have gotten this sick if James had sent him to a “real doctor” instead of saving money by using Doctor Hardy. Defensively, James upholds that Hardy is a perfectly respectable doctor, though he admits to wanting to avoid expensive “society doctors.” He then says Jamie doesn’t know the value of a dollar, lampooning him for leading the life of a wannabe actor on Broadway, where Jamie spends his time drinking and visiting whores. He also accuses Jamie of teaching Edmund his wicked ways, saying the poor boy doesn’t have the “constitution” to lead the kind of life Jamie has taught him. Nevertheless, they agree that Edmund’s wide-ranging adventures as a sailor have done him no good.
James also laments that Edmund is sick, since it’s terrible timing for Mary, who had “control of her nerves” before he became ill. In response, Jamie tells his father that he heard Mary get up in the middle of the night and retreat into the guestroom. He begins to note that this has always been a “sign,” but before he can finish James interrupts to insist that Mary just got up to escape his snoring. They then argue about who’s to blame for Mary’s addiction, with Jamie suggesting that the “cheap quack” who treated Mary after Edmund was born was perhaps responsible for her dependency. As his father refutes this point, though, they quickly change the subject because Mary enters the room. In order to avoid her, they go outside to trim the hedges.
At this point, Edmund comes into the parlor and talks to his mother, who criticizes her husband for never providing the family with a permanent home. Since James was a famous actor, the family was constantly traveling from one place to the next and living in second-rate hotels. According to Mary, this is why Jamie and Edmund were never able to meet respectable women—after all, they didn’t have a presentable home where they could entertain people. As for herself, she has always felt lonely and untethered because of this lifestyle, so much that she deeply misses her days as a young girl in a convent, when she was studying to be a nun or a concert pianist.
During this conversation, Edmund makes references to Mary’s addiction, though she tries to stop him from speaking about the matter and says it “makes it so much harder” to live “in this atmosphere of constant suspicion.” Nevertheless, Edmund says he heard her go into the spare room the previous night. And though she shames him for suspecting, she also admits she understands why he thinks she might relapse. “How can any one of us forget?” she asks. Changing the subject, she tells Edmund he should go outside because it’ll be good for his health. When he leaves, she sits nervously and fidgets with her hands.
That afternoon, Edmund sits in the parlor and has a glass of whiskey with Jamie. Together, they wait for lunch as their father talks outside with a passing neighbor. Meanwhile, Mary comes downstairs, and it’s immediately clear she has taken morphine. Jamie sees this right away, but it takes Edmund longer, especially since Mary won’t look him in the eye. After a moment, she exits, and James finally comes in, has a drink of whiskey (along with his sons), and claims whiskey in “moderation” is healthy, even for a sick person like Edmund. At this point, Mary reenters and goes on a long rant, which she delivers with a sense of distance that James recognizes as a sign of relapse. Then, seeing Edmund’s glass on the table, she worriedly tells him he shouldn’t drink, asking if he remembers her own father, who had consumption but wouldn’t stop drinking and, as a result, died an early death.
Shortly thereafter, James admits he feels like a “fool” for having believed in Mary, and though she pretends to not understand what he’s talking about, she eventually says, “I tried so hard!” In response, James simply says, “Never mind. It’s no use now.” This dynamic continues throughout lunch, with Mary rambling on in a removed manner and frequently casting blame on James for never providing her with a proper home. In keeping with this, she suggests that James is a cheapskate who, despite his riches, fears ending up in the poorhouse.
Eventually, the telephone rings and James answers it, since he’s expecting a call from Hardy, who has news about Edmund’s condition. When returns, he only says that Hardy wanted to make sure Edmund sees him that afternoon. At this point, Mary announces she must go upstairs, and it’s obvious that she wants to take more morphine. Resigned to this reality, James tells her to go right ahead. Then, when she’s gone, Edmund tries to convince his father and brother that they shouldn’t give up on Mary, but they tell him there’s no use trying to intervene now that she has relapsed. Nevertheless, Edmund is undeterred and goes upstairs to reason with her. When he leaves, James tells Jamie that Doctor Hardy informed him that Edmund does indeed have consumption and that he’ll have to go to a sanatorium. He then asks his son to accompany Edmund to the doctor’s, but to refrain from using the excursion as an excuse to get drunk.
When Mary comes downstairs again, she looks even more “detached.” Jamie leaves, and James tries to convince Mary to get out of the house, but she says she doesn’t like being driven around. When Edmund comes downstairs, James gives him money and tells him not to share the cash with Jamie, who will only spend it on alcohol. He then departs. Before Edmund also leaves, he pleads with Mary to stop taking morphine, but she pretends she doesn’t know what he’s talking about. At the same time, she tells him she understands why he doesn’t believe her. Defeated, he exits, leaving her alone.
That evening, Mary sits in the parlor with Cathleen, a housekeeper. Giving Cathleen drinks of James’s whiskey, she speaks nostalgically about the past, telling the young woman about her life in the convent and how good she was at piano. She had decided to become a nun, she explains, but then she went to one of James’s shows and was star-struck by him. That same night, she went to his dressing room, and they fell in love. Since then, she has been traveling with him.
Eventually, James and Edmund come home, and Mary speaks disparagingly about Jamie, who’s out drinking because Edmund gave him some money. Because Mary’s high, she can’t help rambling about the past, often blaming James and Jamie for her troubles. She even talks about Eugene, the child she had after Jamie who, not long after he was born, died of measles. This never would have happened, Mary suggests, if James hadn’t asked her to come on the road with him and leave Jamie with her mother. If Mary herself had stayed home, she upholds, Jamie wouldn’t have been allowed to go into Eugene’s room when he had measles, and so the baby wouldn’t have been infected. Going on, she says that the cheap doctor James hired to treat her when she gave birth to Edmund is to blame for her morphine habit. This is because Edmund’s birth was complicated and messy, and the doctor didn’t know how to properly tend to Mary, so he gave her morphine. As she says these terrible things, Eugene and James come in and out of the room, wanting to avoid her words.
Around midnight, James sits alone in the parlor. He’s extremely drunk and playing cards with himself when Edmund, also thoroughly intoxicated, enters. In an overly sentimental monologue, James tells his son about the highlights of his acting career, admitting that he regrets chasing commercial success at the expense of artistic fulfillment. In turn, Edmund tells his father the high points of his own career as a sailor, talking about the freedom he finds in the loneliness of the ocean. When they hear Jamie stumbling into the house, James decides to wait on the side porch to avoid an argument. As such, Jamie and Edmund have a one-on-one conversation in which Jamie scolds his younger brother for drinking with consumption, then lightens up and lets him continue. At one point, Jamie insults Mary’s honor by talking about her addiction, and Edmund punches him in the face. Jamie readily accepts his mistake and thanks his brother for setting him straight. Before long, he slips into a drunken sleep, and James returns.
When Jamie wakes up again, the three Tyrones pour themselves whiskey and are about to toast when Mary appears in the doorway holding her wedding dress with a distant look on her face. Forgetting their drinks, they watch as she walks around without seeming to notice them, talking all the while as if she’s a younger version of herself. Indeed, she speaks as if she’s still in the convent, and says she’s looking for something, though she can’t remember what. Going on distractedly, she talks about her relationship with one of the nuns, and then she sits down—facing the audience—and stares off into the distance as her drunken family members sit uncomfortably nearby.
