Varya enters. She tells Dunyasha to leave and then launches against Yephikodov, telling him that he does no work at all. She wonders aloud why they even keep a clerk. Yephikodov is deeply offended, especially by the last remark; he haughtily tells her that such things are "for wiser and older heads" than Varya's to decide. Varya is incensed at Yephikodov's words. She tells him to leave instantly. He asks her to "express herself in a more refined manner," but he is clearly frightened. And he has good reason to fear, because Varya moves towards him, threateningly. As she does so, he leaves, but from behind the doorway he tells her he will lodge a complaint. She hears a noise in the hall and, believing him to be coming back, grabs a stick and lashes out.
But Lopakhin enters instead, receiving the end of her stick. Lopakhin and Gayev have returned from the auction. As Lopakhin and Gayev enter, Lopakhin is visibly happy; Gayev is tired and upset and soon leaves. In response to a question by Ranevsky, Lopakhin lets everyone know that he bought the orchard at auction. Furthermore, he plans to go through with his plans for cutting down the cherry orchard and building cottages in its place.
Ranevsky is heartbroken. Varya throws down the keys to the estate and leaves. Lopakhin reflects out loud on how he, the son of local peasants, has come to own the great estate his father and grandfather once worked on, the estate of those who once owned his father and grandfather, and how he will implement changes now that he is in charge.
During his speech, Ranevsky quietly weeps. He goes up to her, but instead of consoling her, he is reproachful. He asks her why she didn't listen to him and says, "my poor dear friend, you can't turn back the clock now." Pischik takes him by the arm and escorts him out of the room.
When he leaves, Anya consoles her mother. She tells her mother that she loves her, and she still has a life to live. And she tells her that they will plant a new cherry orchard, a better one, and that after they do this they will all "smile again."
Lopakhin's revelation, that he has bought the orchard, is the climax of the play. If we wish to read it as a tragedy, then this is the play's catastrophe, its horrific event. But, Chekhov handles the situation comically. Lopakhin waits until the last possible moment to reveal that is was he who bought the orchard. Always the man of facts and figures, he recounts the auction in detail and with glee, including the amount of each bid. As he leaves, he nearly knocks over a candelabra from a table, but instead of being self-conscious about his clumsiness and recognizing it as a sign of his peasant origins, he reacts nonchalantly, saying, "I can pay for everything now." The key word here is "now." Lopakhin's triumph is his final escape from his past and from his memory; his purchase of the orchard is proof that he is the rich businessman he is now, and not the peasant child he remembers himself as being then. Lopakhin's mentioning of his grandparents is of particular interest, for in the moment of the greatest separation from his past he seems not to forget but instead to remember. He ponders, if his grandfather and grandmother "could only rise from their graves to see what has happened" and witness that their grandson, who "used to run around barefoot," is now the owner of the orchard, the place where his grandparents were treated as slaves. But such memories are safe for Lopakhin now, because the implication is that his grandparents would not recognize him: he has proven to their memory, as well as to himself, that he is no longer a peasant.
And Lopakhin contemplates one final act of revenge against the past. "[Y]ou just watch Yermolay Lopakhin get his axe into that cherry orchard, watch the trees come crashing down. We'll fill the place with cottages." The image is one replete with violence; Lopakhin will be personally destroying the trees, destroying what he himself has called "the most beautiful place in the world." His appreciation of this beauty, yet his willingness to destroy it, creates an uneasy tension, leaving us wondering why he not only accepts, but also delights in the thought of destroying the orchard. This tension must exist firmly within Lopakhin himself, since the orchard represents the best that the Russia of Lopakhin's grandparents had to offer. It is "the most beautiful place in the world," and, moreover, so large that it probably could only have been supported by the oppressive economic system then in place. In obliterating it, Lopakhin obliterates the attractive beauty from the memory of that social world, leaving only its repulsive oppression, but he also attempts to obliterate his own oppressive memories of a brutal peasant childhood. So Lopakhin's destruction of the cherry orchard symbolizes his desire to forget his peasant past, as well as the desire that Russia should forget its own peasant past; in other words, its history of serfdom.
But while he exults, Ranevsky weeps. And it is typical that of the dramatic structure of The Cherry Orchard that right after his moment of triumph, Lopakhin acts out his ugliest moment in the play. We see the insensitivity of the celebrating Lopakhin when faced with Ranevsky's sadness, especially when he sees that she is weeping. Instead of consoling her, he goes up to her in a reproachful tone. In effect, he gloats, evoking an I-told-you-so type of response. In previous scenes, we were liable to feel sorry for Lopakhin when he described his thick-headedness and his lack of refinement. But here he proves himself to be deserving of this image—he is "a bull in a china shop," both emotionally (in that he is insensitive) and physically (in that he is clumsy). When juxtaposed with his recent triumph, this behavior is definitely ironic. The irony arises from the fact that while Lopakhin exults about his freedom from his peasant origins, his clumsiness, his insensitivity, and his emotional brutality towards Ranevsky, are all the character traits of a peasant. They thus prove that the brutality of Lopakhin's peasant past is still very much a part of him even if he does forget it. He is infected by it, much as Trofimov thinks all of Russian society is infected by the legacy of serfdom.