In his youth, Fyodor Pavlovich Karamazov is a coarse, vulgar man whose main concerns are making money and seducing young women. He marries twice and has three sons: Dmitri, the child of his first wife, and Ivan and Alyosha, children of his second wife. Fyodor Pavlovich never has any interest in his sons, and when their mothers die, he sends them away to be brought up by relatives and friends. At the beginning of the novel, Dmitri Karamazov, who is now a twenty-eight-year-old soldier, has just returned to Fyodor Pavlovich’s town. Fyodor Pavlovich is unhappy to see Dmitri because Dmitri has come to claim an inheritance left to him by his mother. Fyodor Pavlovich plans to keep the inheritance for himself. The two men swiftly fall into conflict over the money, and the coldly intellectual Ivan, who knows neither his father nor his brother well, is eventually called in to help settle their dispute. The kind, faithful Alyosha, who is about twenty, also lives in the town, where he is an acolyte, or apprentice, at the monastery, studying with the renowned elder Zosima. Eventually Dmitri and Fyodor Pavlovich agree that perhaps Zosima could help resolve the Karamazovs’ quarrel, and Alyosha tentatively consents to arrange a meeting.
At the monastery, Alyosha’s worst fears are realized. After Fyodor Pavlovich makes a fool of himself by mocking the monks and telling vulgar stories, Dmitri arrives late, and Dmitri and Fyodor Pavlovich become embroiled in a shouting match. It turns out that they have more to quarrel about than money: they are both in love with Grushenka, a beautiful young woman in the town. Dmitri has left his fiancée, Katerina, to pursue Grushenka, while Fyodor Pavlovich has promised to give Grushenka 3,000 rubles if she becomes his lover. This sum is significant, as Dmitri recently stole 3,000 rubles from Katerina in order to finance a lavish trip with Grushenka, and he is now desperate to pay the money back. As father and son shout at each other at the monastery, the wise old Zosima unexpectedly kneels and bows his head to the ground at Dmitri’s feet. He later explains to Alyosha that he could see that Dmitri is destined to suffer greatly.
Many years previously, Fyodor Pavlovich Karamazov fathered a fourth son with a retarded mute girl who lived in town as the village idiot. The girl died as she gave birth to the baby, who was taken in by servants of Fyodor Pavlovich and forced to work as a servant for him as well. Fyodor Pavlovich never treats the child, Smerdyakov, as a son, and Smerdyakov develops a strange and malicious personality. He also suffers from epilepsy. Despite the limitations of his upbringing, however, Smerdyakov is not stupid. He enjoys nothing more than listening to Ivan discuss philosophy, and in his own conversations, he frequently invokes many of Ivan’s ideas—specifically that the soul is not immortal, and that therefore morality does not exist and the categories of good and evil are irrelevant to human experience.
After the humiliating scene in the monastery, the rest of Alyosha’s day is only slightly less trying. Dmitri sends Alyosha to break off Dmitri’s engagement with Katerina. Alyosha then argues about religion with Ivan in front of the smirking Fyodor Pavlovich. Alyosha also gets caught in the middle of another explosion between Dmitri and Fyodor Pavlovich over Grushenka, in the course of which Dmitri throws Fyodor Pavlovich to the ground and threatens to kill him. But despite the hardships of his day, Alyosha is so gentle and loving that he is concerned only with how he might help his family. After tending his father’s wounds, he returns to the monastery for the night.
The next day, Alyosha visits Katerina. To his surprise, Ivan is with Katerina, and Alyosha immediately perceives that Ivan and Katerina are in love. Alyosha tries to convince them that they should act on their love for one another, but they are both too proud and cold to listen. Alyosha has dinner with Ivan, and Ivan explains to him the source of his religious doubt: he cannot reconcile the idea of a loving God with the needless suffering of innocent people, particularly children. Any God that would allow such suffering, he says, does not love mankind. He recites a poem he has written called “The Grand Inquisitor,” in which he accuses Christ of placing an intolerable burden upon humanity by guaranteeing that people have free will and the ability to choose whether or not to believe in God.
That evening, Alyosha again returns to the monastery, where the frail Zosima is now on his deathbed. Alyosha hurries to Zosima’s cell, and arrives just in time to hear his final lesson, which emphasizes the importance of love and forgiveness in all human affairs. Zosima dies stretching his arms out before him, as though to embrace the world.
Many of the monks are optimistic that Zosima’s death will be accompanied by a miracle, but no miracle takes place. If anything, Zosima’s corpse begins to stink more quickly than might have been expected, which is taken by Zosima’s critics to mean that he was corrupt and unreliable in life. Sickened by the injustice of seeing the wise and loving Zosima humiliated after his death, Alyosha allows his friend Rakitin to take him to see Grushenka. Although Rakitin and Grushenka hope to corrupt Alyosha, just the opposite happens, and a bond of sympathy and understanding springs up between Grushenka and Alyosha. Their friendship renews Alyosha’s faith, and Alyosha helps Grushenka to begin her own spiritual redemption. That night, Alyosha has a dream in which Zosima tells him that he has done a good deed in helping Grushenka. This dream further strengthens Alyosha’s love and resolve, and he goes outside to kiss the ground to show his passion for doing good on Earth.
Dmitri has spent two days unsuccessfully trying to raise the money to pay Katerina the 3,000 rubles he owes her. No one will lend him the money, and he has nothing to sell. At last he goes to Grushenka’s house, and when she is not there, he is suddenly convinced that she has gone to be with Fyodor Pavlovich. He rushes to Fyodor Pavlovich’s house, but finds that Grushenka is not there. While prowling on the grounds, Dmitri strikes Fyodor Pavlovich’s old servant, Grigory, leaving him bloody and unconscious. Then he flees. He returns to Grushenka’s house, and learns from her maid that Grushenka has gone to rejoin a lover who abandoned her several years ago. Dmitri now decides that his only course of action is to kill himself. But he decides to see Grushenka one last time before he does so.
A few minutes later, Dmitri strides into a shop, with his shirt bloody and a large wad of cash in his hand. He buys food and wine, and travels out to see Grushenka and her lover. When Grushenka sees the two men together, she realizes that she really loves Dmitri. Dmitri locks the other man in a closet, and Dmitri and Grushenka begin to plan their wedding. But the police suddenly burst in and arrest Dmitri. He is accused of the murder of his father, who has been found dead. Due to the large amount of evidence against Dmitri, including the money suddenly found in his possession, he will be made to stand trial. Dmitri says that the money was what he had left after spending half of the 3,000 rubles he stole from Katerina, but no one believes him. Dmitri is imprisoned.
Meanwhile, Alyosha befriends some of the local schoolboys. He meets a dying boy named Ilyusha, and arranges for the other boys to come visit him every day. Alyosha helps Ilyusha’s family as the young boy nears death, and he is universally adored by all the schoolboys, who look to him for guidance.
Ivan talks to Smerdyakov about Fyodor Pavlovich’s death, and Smerdyakov confesses to Ivan that he, and not Dmitri, committed the murder. But he says that Ivan is also implicated in the crime because the philosophical lessons Smerdyakov learned from Ivan, regarding the impossibility of evil in a world without a God, made Smerdyakov capable of committing murder. This statement causes Ivan to become consumed with guilt. After returning home, Ivan suffers a nervous breakdown in which he sees a devil that relentlessly taunts him. The apparition vanishes when Alyosha arrives with the news that Smerdyakov has hung himself.
At the trial, Dmitri’s case seems to be going well until Ivan is called upon to testify. Ivan madly asserts that he himself is guilty of the murder, throwing the courtroom into confusion. To clear Ivan’s name, Katerina leaps up and shows a letter she received from Dmitri in which he wrote that he was afraid he might one day murder his father. Even after the letter is read, most of the people in the courtroom are convinced of Dmitri’s innocence. But the peasants on the jury find him guilty, and he is taken back to prison to await his exile in Siberia.
After the trial, Katerina takes Ivan to her house, where she plans to nurse him through his illness. She and Dmitri forgive one another, and she arranges for Dmitri to escape from prison and flee to America with Grushenka. Alyosha’s friend Ilyusha dies, and Alyosha gives a speech to the schoolboys at his funeral. In plain language, he says that they must all remember the love they feel for one another and treasure their memories of one another. The schoolboys, moved, give Alyosha an enthusiastic cheer.