Larina and Filipyevna are working outside and reminiscing about the past, remembering how Larina changed from a foolish romantic girl to a sedate and contented wife.
The peasants of the estate sing as they return from harvesting, and Tatyana and Olga come out to listen. Tatyana's imagination is stirred by the song but Olga laughs at her, contrasting her own simple, light-hearted view of life with her sister's moody day-dreaming. The peasants go and Tatyana starts reading. Her mother is anxious because she is so pale but Tatyana answers that she is not ill, only deeply moved by the sufferings of the characters in her book.
The arrival of Lensky, Olga's fiancee, causes a flutter, particularly when it is discovered that he has brought a stranger. Lensky presents Onegin, a neighbor in the country. Tatyana falls in love with him on the spot and he expresses surprise to Lensky that his friend, as a poet, should have preferred the prosaic Olga to the more striking Tatyana.
The couples separate. Lensky and Olga leave Tatyana and Onegin to make polite conversation in which she explains that she does not find the country boring, as he supposes, because of her fondness for reading and day-dreaming. Then they wander off and Olga and Lensky return, the latter expressing his devotion to Olga, whom he has loved since childhood. As night falls they go inside. As Tatyana and Onegin return, Onegin complains about the tedium of sitting by his dying uncle's bedside. Filipyevna notices Tatyana's emotion and wonders whether she might be falling in love with Onegin.
That night, Tatyana is restless and asks Filipyevna about her youth and marriage, but does not really listen to the nurse's story of her arranged marriage. Crying out that she is in love, she asks to be left alone. She writes a letter to Onegin in which she expresses her love, her fears and her doubts. When Filipyevna returns in the morning, Tatyana asks her to have her grandson take the letter to their neighbor. She is unwilling to speak Onegin's name but angry when the nurse does not immediately realise which neighbor.
Later, the servant girls are singing as they pick berries. Tatyana waits fearfully for Onegin. Politely he tells her that love is not for him. If he had been meant to have a wife he would have had none other than her, but as he is he would make her miserable. He offers her the love of a brother - perhaps even more - but warns her to be more cautious in future, as not everyone will be so forbearing as he.
Some months later, at party in honor of Tatyana's name day, as the guests dance and express their approval of the arrangements Onegin overhears some women criticizing his character. Angrily he determines to be revenged on Lensky, whom he blames for dragging him to the party, by flirting with Olga. Lensky is at first bewildered and then angry, and reproaches both Olga and Onegin; and Olga refuses to dance with him as a punishment. An elderly guest, Monsieur Triquet, reads out some couplets to the embarrassed Tatyana.
Lensky resumes his attack on Onegin who tries to calm him, claiming that he has done nothing to upset anyone and pointing out that people are beginning to take notice of them. Larina begs them not to quarrel in her house and Lensky sadly recalls the happy times he has spent there while Onegin regrets the length to which the affair has gone and Tatyana gives vent to the jealousy which his attentions to Olga has aroused in her. Eventually Lensky flings out a definite challenge which Onegin is unable to refuse. As they leave the room Olga falls in a faint.
Early the next morning, Lensky and his second, Zaretsky, are waiting for Onegin near a water mill. Lensky reflects with gentle melancholy on the passing of his youth, his possible impending death and his love for Olga. When Onegin appears (with only his manservant Guillot as his second, to the disapproval of Zaretsky, a stickler for correct duelling procedure), he and Lensky muse separately on the possibility of making up their quarrel, but decide they have gone too far to retreat. Onegin fires first and Lensky falls dead. Onegin is appalled.
Some years later, at the ballroom of a nobleman's house in St Petersburg Onegin, who is standing apart, muses on his life since the duel. He had fled his country estate and travelled but now, bored, he has returned, only to find himself at a ball. Among the guests is an elegant Lady whom he recognizes with astonishment as Tatyana. She notices him and tries to control her emotion. When he asks an old friend, Prince Gremin, who she is, he finds that she is Gremin's wife. Gremin bursts into a eulogy on Tatyana and his love for her.
Onegin and Tatyana meet, both apparently calm, and they exchange a few civilities before she tells her husband she is tired and they leave. Onegin realises with astonishment that he is in love with her.
Tatyana holds a letter which Onegin has written to her declaring his love. She is upset that he has returned to disturb her peace of mind. Onegin enters to find her in tears and falls at her feet. She collects herself and reminds him of his rejection of her in the garden. When he exclaims he now realizes his mistake, she asks if he finds the society woman a more suitable prize to add to his conquests than the simple country girl. He tries to convince her that his feelings are genuine. They both reflect on the happiness that has passed them by, and Tatyana tells Onegin that fate has decided otherwise: she is married and he must leave her.
Passionately he tries to persuade her, but she reminds him that he is an honorable man. She admits that she does still love him but tells him that now she is married she will remain faithful to her husband. In vain he protests. She bids him farewell forever, and leaves him overcome by despair.
