Anna Karenina braids together two stories. In the first, Anna, the graceful wife of the cold Petersburg official Karenin, falls in love with the cavalry officer Vronsky. What begins as a brilliant attraction becomes a full affair; Anna leaves her husband and small son, bears Vronsky a daughter, and tries to build a life on a love that society will not forgive.
In the second story, the awkward, earnest landowner Konstantin Levin courts Kitty Shtcherbatsky, is at first refused, and later wins her. His thread is quieter and more inward: farming his estate, arguing about reform and faith, marrying, and learning the daily friction and joy of a shared life. Levin is widely read as Tolstoy's self-portrait.
The two arcs mirror each other. Anna and Vronsky have everything passion promises and yet drift toward jealousy, suspicion, and a closing-in of their world, cut off from the society that once admired them. Levin and Kitty have an ordinary, sometimes difficult marriage that slowly deepens into something solid. Around them moves a third pair, Anna's brother Stepan Oblonsky and his wife Dolly, whose worn marriage shows the everyday compromise that Anna refuses.
As her isolation grows, Anna comes to doubt Vronsky's love and to read cruelty and betrayal into everything. Her thought spirals; the world she sees fills, in Tolstoy's image, with troubles, falsehoods, sorrow, and evil. In the novel's most famous turning point she throws herself beneath a train, and the light by which she had read that book of life flickers and is quenched.
Levin's story carries the book to its close. Tormented by the meaninglessness of life in the face of death, and unable to reason his way to faith, he is shaken by a peasant's offhand remark that a good man lives not for his belly but for his soul, for God. Levin does not become suddenly happy or transformed, but he grasps that his life can hold the positive meaning of goodness, which he has the power to put into it. The two destinies, one ending in self-destruction, one in fragile faith, together form Tolstoy's meditation on love, marriage, society, and how to live.