A man named Clov walks stiffly around a room with two windows set high on opposite walls. At the center of the room sits Hamm, a blind man confined to a wheeled armchair. Clov walks between the windows, climbing a small ladder to peer through each one. After looking for a moment, he lets out a sharp laugh before falling silent, at which point he walks to the two trashcans next to Hamm’s chair and opens them, laughing when he looks inside. He then uncovers Hamm, who has been sitting underneath a large sheet. With a bloodied handkerchief draped over his face, Hamm sleeps while Clov laughs and then, emotionlessly, says, “Finished, it’s finished, nearly finished, it must be nearly finished.” Having said this, he decides to retreat to the kitchen connected to this room, where he’ll wait for Hamm to summon him with a whistle.
When Clov exits, Hamm wakes up and takes off his bloody handkerchief, using it to wipe his glasses before putting them on again and wondering aloud if misery greater than his could possibly exist in the world. Considering this for a moment, he decides that his mother, father, and dog must certainly experience the same level of suffering as him. He also decides it’s time for things—it’s unclear what, exactly—to end, though he admits that he himself “hesitate[s] […] to end. He then calls Clov, wanting to be put to bed. Entering, Clov points out that he just roused Hamm, insisting that he can’t spend his entire time getting him up and then putting him to bed over and over. After all, Clov says, he has things to do. This doesn’t bother Hamm, who asks Clov what time it is. “The same as usual,” Clov replies. Hamm asks if Clov has looked out the window. Clov assures him that he has, and when Hamm asks what he saw, he says, “Zero.”
As their discursive conversation continues, Hamm and Clov agree that they’ve “had enough.” Suddenly, Hamm turns on Clov and threatens to starve him to death, but Clov reminds him that this would cause both of them to die. Taking this into account, Hamm decides to give Clov just one biscuit every day, thereby keeping him alive but in a constant state of hunger. This doesn’t bother Clov, who turns to fetch the sheet to cover Hamm. Before he does, though, Hamm asks why he stays with him, and Clov responds by asking why Hamm lets him stay. “There’s no one else,” Hamm says, to which Clov adds, “There’s nowhere else.” Still, Hamm points out that Clov is going to leave him, and Clov admits that he’s attempting to do so.
At one point, Hamm asks Clov if he can take his painkiller, but Clov says it’s not yet time. Moving on, Hamm asks why Clov won’t simply kill him, and Clov says he doesn’t know the combination of the cupboard (never making clear what this cupboard contains). Allowing Clov to finally retreat to the kitchen, Hamm remarks that everything is death outside of this room.
Just before Clov goes into the kitchen, one of the trash cans next to Hamm opens, and Nagg’s head appears. He listens to their conversation for a moment, and when Clov leaves, he asks for pap (a soft food often fed to babies). “Accursed progenitor!” Hamm swears, blowing his whistle to summon Clov, who says there’s no more pap. Nagg complains about this, so Hamm tells Clov to give him a biscuit. Once he has this biscuit, Nagg protests, saying it’s too hard for him to eat. Annoyed, Hamm orders Clov to close the lid of Nagg’s trash can. He then tells Clov to sit on the lid, but Clov reminds him that he’s incapable of sitting. “True,” Hamm says. “And I can’t stand.” Both men then reflect upon the state of nature, asserting not only that nature has forgotten them, but that there is no more nature—though they take this back when Hamm points out that they continue to age and decay, meaning that nature hasn’t forgotten them.
Clov says he has things to do, maintaining that he must go back to the kitchen to continue staring at the wall. Once again, Nagg pops up, this time sucking on the biscuit. Hamm declares that he’s not having any fun, though he concedes that this is always the case, especially at the end of a day. Suddenly, though, he asks Clov what is happening, and Clov says, “Something is taking its course.” Agreeing, Hamm tells Clov to leave, and Clov says that he’s been trying to for a long time.
Nagg raps his hand against the trashcan next to him, and a woman named Nell pops up from within it, asking what he wants and if it’s “time for love.” They then try to kiss, but their heads won’t reach each other. Nagg launches into a memory about when he and Nell—his wife—lost their legs in a tandem bike crash. Moving on, Nagg offers Nell half of his biscuit, but she’s uninterested. Meanwhile, Hamm tells them to be quiet, complaining that their conversation is keeping him from falling asleep and dreaming of running freely into the woods. He also says there’s a heart inside of his head that is dripping—a statement that makes Nagg laugh, though Nell scolds him, saying he shouldn’t laugh at such things. However, she also says there’s nothing funnier than unhappiness, though she sees no reason to laugh, since misery is so common that it’s like a funny joke one has heard many times—there is, she says, no point in laughing, since the joke has been told time and again, though it’s still funny.
Nagg asks Nell if she’s going to leave him, and she assures him that she will, but first Nagg insists upon telling a funny story. Nell doesn’t want to listen, but Nagg forces her, reminding her that she used to love this story. Going on, he delivers a joke about a man who brings his suit to a tailor, who keeps delaying the final product because of the mistakes he makes along the way. Once he finishes, he laughs at his own strange tale, at which point Hamm shouts at him to be quiet. Nagg sinks back into his trashcan and closes the lid, and Nell begins to speak nonsensically about deserts, so Clov feels her pulse, declaring as he pushes her back into her trashcan and closes the lid that she doesn’t have a heartbeat.
Hamm asks again for his painkiller, but Clov doesn’t give it to him. Turning his attention to other matters, Hamm makes Clov push his chair around the room in a large circle before setting him back in the center. As a casual aside, Clov remarks that he would be happy if only he could kill Hamm, but this comment doesn’t bother Hamm, who continues to ask seemingly random questions about the outside world, forcing Clov to look out the window with a telescope. Again, he describes what he sees as “zero,” adding that it’s nothing but a wash of greyness. After he says this, Hamm asks once more what’s happening, and Clov responds again by saying that “something is taking its course.” In response, Hamm asks if he and Clov are beginning to “mean something,” but Clov dismisses this as a ludicrous idea. All the same, Hamm urges Clov to imagine what it would be like if a “rational being came back to earth” and observed them. This being, Hamm says, might try to draw certain ideas about what Hamm and Clov are doing.
Interrupting Hamm, Clov looks down his own pants and declares that he has a flea. This astounds Hamm, who’s surprised to hear that fleas still exist. He orders Clov to sprinkle insecticide down his pants to ensure that the flea dies, worrying that humanity might begin all over again if he doesn’t kill the flea. Once this ordeal is settled, Hamm says that Clov will one day become like him, deciding to rest and then finding that he can’t move anymore. Clov agrees that this might happen, but he reminds Hamm that he can’t sit down, so Hamm revises his prediction by saying that Clov will simply remain on his feet, upholding that the effect will be the same. Once again, they talk about whether or not Clov will leave, and then Hamm suggests that he should “finish” them both, saying that he’ll tell him the combination to the cupboard. In response, Clov says that he couldn’t possibly finish Hamm. Continuing their conversation, Hamm talks about when Clov first arrived—a time Clov himself can’t remember because he was too young.
Hamm then asks for his dog, so Clov brings him a stuffed animal with only three legs. Hamm doesn’t seem to understand that the dog isn’t real, treating it as if it’s alive. As the day passes, Hamm and Clov continue their discussion about whether or not Clov will leave, alternating between wanting this to happen and wanting it not to happen. At one point, Hamm wonders how he’ll know whether or not Clov has left or died when he one day calls for him and he doesn’t come. To solve this problem, Clov says he will set an alarm clock if he ever leaves. If Hamm calls him and he doesn’t come and the alarm clock goes off, Hamm will know he left. If he calls him and he doesn’t come but the alarm clock doesn’t go off, he’ll know Clov died in the kitchen.
Abruptly, Hamm says it’s time for him to tell a story, forcing Clov to wake up Nagg to listen. When Nagg pops up, Hamm curses him, asking why he decided to give him life (it becomes clear here that Nagg and Nell are Hamm’s parents). Then, commenting on his own style of narration as he goes, Hamm tells a story about a man coming to him on Christmas Eve and asking for help. The man explained that he and his son were starving to death. He told Hamm that he left his son at home, and asked if Hamm would take them both in. After a moment of deliberation, Hamm agreed, though not before disparaging the man for thinking that he could ever do anything to make life better. “Use your head, can’t you, use your head, you’re on earth, there’s no cure for that!” he yelled. As he concludes his story, it becomes obvious that Clov is the young boy whose father asked Hamm for help.
Hamm and Clov keep talking about how everything will soon end. Eventually, they discover that Nell has died in her trashcan, but they don’t make a big deal of the matter. Instead, they focus on their disjointed conversations. Clov, for his part, wonders aloud why he always does what Hamm tells him to, and Hamm suggests that perhaps he feels compassion toward him. Looking out the window, Clov thinks he sees a young boy, but both he and Hamm agree that it doesn’t matter even if what he has seen is real.
Clov finally decides to leave, and Hamm asks him to say something before departing. Clov speaks abstractly about friendship, suffering, and the strange passage of time. Hamm thanks Clov for all of his help, and Clov thanks Hamm in return. Clov then stops answering Hamm, stepping into the kitchen to collect his things before going. When he returns, Hamm is still speaking, and he watches with his coat folded over his arm, apparently unable to tear himself away. Unsure whether or not Clov is still there, Hamm addresses his bloody handkerchief, remarking that it has remained with him. He then drapes it over his face and stops speaking.