Anna Karenina, considered by many critics to be Tolstoy's finest achievement, is one of the most important novels of the nineteenth century. Tolstoy imbues the simple tale of a love affair with rich portraits of Russian high society, politics, and religion.
As the book opens, Prince Stephen Oblonsky, known as Stiva, is arguing with his wife, Dolly: he has had an affair with their children's governess, and she is threatening to leave him. He is happy that his sister, Anna Karenina, will be coming the next day to visit and smooth things over between himself and Dolly. Anna is married to a distinguished official in St. Petersburg, and moves in the highest circles of Russian Society with the reputation of a charming woman.
That same day, Oblonsky runs into his friend Constantine Levin, who has just arrived from his country estate. Levin is in town to see Oblonsky's sister-in-law, Kitty Shcherbatskaya, for Levin is rather smitten with the eighteen-year-old girl. Oblonsky suggests a meeting with Levin later that evening at the park where Kitty ice-skates.
Levin goes to the park. He skates with Kitty and flirts with her boldly, but she sends him mixed signals. At dinner with Oblonsky that night, Levin learns that he has a rival for Kitty's affections: Count Alexis Kirilovich Vronsky. And indeed, when Levin proposes to Kitty, but she rejects him in the hopes that Vronsky will make his proposal soon.
When Oblonsky goes to the railway station to meet Anna the next morning, he runs into Vronsky, who is waiting for his mother to get off the same train. It turns out that Anna and Vronsky's mother were seatmates in the same compartment, and his mother is quite taken with Anna. So is Vronsky, at once, charmed by Anna's spirit and vitality. Before they leave the station, a railroad guard is run over and killed by a passing train. At the urgings of Anna, Vronsky leaves 200 roubles for the guard's widow.
Anna ably convinces Dolly not to leave Oblonsky. At a ball the next night, Kitty notices that Vronsky is distracted and inattentive to her. The source of this inattention becomes clear when she watched Vronsky waltz with Anna. The two of them are completely smitten, and Kitty's heart is shattered. She realizes that her hopes are shot; Vronsky never wanted to marry her.
Levin goes to see his elder brother Nicholas, who is sickly and lives in depraved conditions. Disgusted with the entire trip, Levin leaves Moscow. Anna leaves the same day as Levin, on the train for St. Petersburg. During a brief stop, Vronsky emerges on the platform and tells her that he is in love with her and will follow her to St. Petersburg. Anna claims that this is impossible and tries to resume her life, but she is constantly displeased with everything.
Kitty Shcherbatskaya's heartache manifests itself in physical symptoms. Her family decides to take her to a spa in Germany to recover.
Upon her return to St. Petersburg, Anna begins circulating more frequently in the circles where she is sure to meet Vronsky. Anna tells herself that she simply enjoys the attention, but soon she admits to herself that his feelings constitute the whole passion of her present existence. Their behavior quickly escalates into the realm of the Socially Unacceptable. Karenin is a man vitally concerned with external appearances, and it is for this reason that he confronts Anna. She disregards his concern, and the couple swiftly withdraws from each other. Vronsky and Anna consummate their love and Anna says, "Everything is finished. I have nothing but you now. Remember that."
Meanwhile, Levin prepares his estate for the arrival of spring. Unlike many estate owners, Levin delights in doing heavy labor on his estate. Oblonsky comes to visit his estate to sell one of his forests to a local dealer named Ryabinin at a serious loss. Before he leaves, Oblonsky tells Levin that Kitty is ill and that Vronsky has left Moscow in pursuit of Anna.
In Petersburg, Vronsky and Anna's affair is rapidly becoming common knowledge. Petersburg Society is waiting eagerly for Anna's downfall, and Vronsky's family is becoming concerned that this affair is distracting him from progressing in his career. In the midst of all this concern, Vronsky is preparing to ride in a horse race. Right before the race, Vronsky visits Anna. She tells him that she is pregnant. Vronsky then hurries to the race. Anna and her husband both attend the race, but sit separately in the stands. Vronsky's horse falls and breaks her back, though he himself is unhurt.
At the race, Karenin watches as Anna reacts physically when Vronsky falls. He confronts her about her affair, with more strength this time. Anna confesses her feelings for Vronsky and says that she hates Karenin. Karenin demands that she observe "external conditions of propriety" until he can protect himself, presumably through a divorce.
At the German spa, Kitty makes the acquaintance of Varenka, a pious young woman. Kitty tries to imitate her sense of deep spirituality and tries to be charitable like the girl. She fails to achieve the same type of understanding with the less fortunate as Varenka has, but comes to a greater understanding of herself by the time she leaves the spa. Meanwhile, Dolly and the children move to their country estate to save money while Oblonsky is in St. Petersburg. Levin visits them, and Dolly suggests that he propose to Kitty again. The suggestion embarrasses Levin. But when he glimpses Kitty a few days later, he realizes that he still loves her.
Karenin decides that the only option is to force Anna to break off relations with Vronsky and stay with him. Outwardly at least, this will preserve the status quo. The same morning, Vronsky receives a visit from his friend Serpukhovskoy, who offers him the chance to jump-start his career by leaving the regiment, Vronsky refuses because it will take him away from Anna.
Levin attempts to avoid thoughts of Kitty, who is staying with Dolly less than twenty miles away. He develops a "theory" of economic labor that involves cooperative labor and ownership. He attempts to implement this theory on his farm, but the peasants respond with far less enthusiasm than Levin does. At the end of September, Levin receives a surprise visit from his consumptive brother Nicholas. Nicholas is emaciated and obviously very sick; his death is imminent. After Nicholas leaves, Levin sinks into moroseness. He begins seeing death everywhere and is depressed about his own soul.
The Karenins are living together in a state of tension. Anna continues to see Vronsky outside the house. One night, the two men meet each other as Vronsky rushes in to see Anna. This is the first night Vronsky notes that Anna's jealous fits make her less attractive to him. Anna tells him of a nightmare she had concerning a dirty old peasant. Vronsky had the same nightmare and is horrified. Karenin confronts Anna again. Faced with her implacable resolve, he tells her that he intends to begin divorce proceedings.
During a dinner party at the Oblonskys', Levin and Kitty reunite and find a new interest in each other. Kitty hints that she would accept if Levin were to propose to her again. This he does, and they begin planning their marriage.
Anna lies close to death after giving birth to Vronsky's daughter. Vronsky is in an outer room, weeping. Seeing Anna in her agitated state stirs Karenin to forgiveness. Weeping freely, he forgives both her and Vronsky in a state of great joy and happiness. Karenin shames Vronsky by saying that no matter how the two of them humiliate him, Karenin will not leave Anna. Devastated by Karenin's nobility, Vronsky goes home and attempts suicide by shooting himself with a revolver. The bullet misses his heart, and he recuperates with the help of his sister-in-law. As she recovers, Anna remains awed by her husband's generous feelings, but she still feels stifled. Oblonsky, sensing the torture of the situation, visits Karenin and encourages him to begin divorce proceedings again. In an emotional moment, Karenin agrees. Upon hearing this news, Vronsky immediately abandons his military duties and rushes to the Karenins' house. But though Anna is elated to see him, she will not accept Karenin's offer of a divorce.
Levin and Kitty have a wonderful marriage despite Levin's concern about his agnoticism. The conversations of the other guests about the failed marriages they are in or that they know of add a sober note to the proceedings.
Anna and Vronsky leave Russia and travel in Italy. Vronsky has a new interest in painting and has begun a portrait of Anna. He abandons this interest when he meets a famous painter named Mikhailov. Mikhailov's superior dedication to the craft, along with his superior portrait of Anna, do a great deal to undermine Vronsky's confidence. They decide to return to Russia.
Levin is disillusioned that his marriage seems to consist of petty quarrels that he had once laughed at in other married couples. Things do not begin to go smoothly until Levin receives news that his brother, Nicholas, is on the verge of death in Moscow. Kitty goes along and takes care of the dying man with great care and tenderness. Levin gains a new appreciation for her. Kitty announces her pregnancy soon after Nicholas dies.
Karenin suffers under the humiliations of public opinion and a stagnated career. His only friend is Countess Lydia Ivanovna, who encourages him to join her in her brand of emotional Christianity. When they return to St. Petersburg, Anna and Vronsky are greeted with the unfortunate news that they have been outcast from high society, especially Anna. Still, Anna tests this by attending the opera. Anna creates a scene and is insulted by members of society. Anna blames him for her social position, making it necessary for him to soothe her with constant assurance of his love. They move to his country estate.
Many people visit the Levins at their estate that summer. Varenka and Koznyshev have a brief romance that ends when Koznyshev is too shy to propose. Oblonsky arrives with Vasenka Veslovsky, a handsome young playboy, who proceeds to flirt inappropriately with Kitty. Levin, who already feels insecure about his relationship to Kitty, fears adultery and throws Veslovsky out.
One day, Dolly goes to visit Anna at Vronsky's country estate. Though at first she is impressed by the luxury Anna and Vronsky live in, and of Anna's vitality, she soon becomes uncomfortable. They have had to consort with lower classes of people and are surrounded by hangers-on. Plus, Anna is in decline: she refuses to accept Karenin's offer of a divorce, she cares little for her daughter, takes morphia in order to sleep, and uses birth control for fear that Vronsky will lose interest in her if she becomes pregnant again.
Anna is increasingly paranoid and dependent on Vronsky. When he attends elections in Moscow and stays one day later than planned, she tricks him into returning. Vronsky feels increasingly stifled by her demands. At last she agrees to write Karenin for a divorce and the couple moves to Moscow.
The Levins are also in Moscow, awaiting the birth of their first child. Levin is uncomfortable in the city but does the best he can. Under Oblonsky's influence, Levin not only makes peace with Vronsky but also agrees to visit Anna, whom he has never met. Levin is completely charmed by Anna. When he returns home, Kitty is furious that he went to see Anna and can see the change in him. He stays up late comforting Kitty and assuring her of his love. Meanwhile, Anna's hold over Vronsky is crumbling; they typically greet each other with hostility. She has not heard from Karenin about her request for a divorce, and this makes their relations still more tense. That night, Kitty goes into labor. The birth takes 22 hours and Levin prays for the first time in years. When his son is born, Levin experiences a feeling of profound joy and happiness.
Oblonsky visits Karenin to press him about divorcing Anna. Karenin reacts with great emotion and claims that his Christianity will not allow him to do such a thing. Meanwhile, relations between Anna and Vronsky continue to sour. Anna grows more jealous, and Vronsky goes colder and more distant. Vronsky spends more time out of the house, and his mother encourages him to marry the young Princess Sorokin. They quarrel that night and then again the next morning; Vronsky leaves in disgust. Anna takes a dose of morphia and writes Vronsky a note begging his forgiveness and pleading with him to return at once. Then, despairing, she goes to visit Dolly.
The next several chapters take place mostly in Anna's head. She goes to see Dolly, but Kitty is there. The two sisters react to Anna awkwardly, and they have little to talk about. She leaves and returns home, where she finds everything and everyone repulsive. Desperate to see Vronsky, she leaves for the Nizhni train station. On the way to the train station, Anna is in a terrifying mental state. To her, everything is despicable and the world is full of ugliness, misery and hate. Overwhelmed, she gets off the train after one stop. She runs into Vronsky's coachman, who gives her a cold note from Vronsky. Insane with misery, she wanders along the platform. Suddenly, she remembers the porter who died the first day she met Vronsky, and decides what she must do. She descends onto the tracks and waits for the oncoming train. She dies begging God for forgiveness, and her last vision is of the peasant from her dream.
Two years later, there is a great movement of Russian sympathy towards the Slavic peoples ruled by the Serbs. When Levin's half-brother Koznyshev goes to the train station to head to Levin's country estate, there are several groups of men who are volunteering to fight with the Slavs. One of those volunteers is Vronsky. The volunteer movement is Vronsky's only hope; he has been a wreck since Anna's death. The fight has given him something to be interested in. Alexis Karenin has taken Vronsky's daughter, and Vronsky is unable to get her back. Vronsky has aged many years and acts as though he is living in a mental prison.
The Levins' home is a portrait of domesticity and happy, effective labor. Levin is tortured by religious doubts and spiritual strivings, and these matters are so clearly troubling to him that even Kitty has begun to question what is going on in her husband's head. Levin's basic question, as he puts it, is this: "If I don't accept the answers given by Christianity to the questions of my life, what answers do I accept?" He wonders about his moment of prayer during Kitty's labor and constantly questions and tortures himself about his doubts. At times it becomes so bad that he wishes to kill himself. He attempts to distract himself with his family and farm duties, and in this he is moderately successful.
He experiences an epiphany in a conversation with a peasant named Theodore. He realizes that he has already been living for God. By appreciating his family and his workers, and dedicating himself to the well-being of others around him, he is behaving the way God wishes him to. He is reinforced in this belief when a tremendous thunderstorm strikes and he rushes to look for Kitty and the baby in the woods. While he hunts for them, lightening strikes a tree in front of him. The tree is scorched and tumbles in front of him. When he finds them a moment later, unhurt, he is overcome with relief. The experience renews his belief in God. Later that night, Levin reflects once more on the nature of his questions, and decides that his belief in God belongs to him alone, and that he has no right to remark on others' relationships with the Lord. Kitty comes in and asks him what he is thinking about, but he demurs to talk to her about it. It is a personal matter, he realizes, one that may not affect his external life but that will make all the difference to his inner peace.