In the France of the Restoration, between the small town of Verrières, the seminary at Besançon and the Paris salons, Julien Sorel, son of a carpenter who owns a sawmill, dreams of Napoleonic glory and discovers that the only path open to his ambition is the cassock. The novel follows this ascent and the fall that ends it.
Book I
In Verrières, a small town in the Franche-Comté, Mayor Monsieur de Rênal decides to hire as tutor for his children the young Julien Sorel, son of the carpenter Sorel, owner of the sawmill, who studies theology and knows the New Testament in Latin by heart. Frail, scorned by his father and brothers, Julien hides a portrait of Napoleon and the Memorial of Saint Helena, and enters the Rênal house as one enters enemy territory. The lady of the house, Madame de Rênal, expected a dirty priest and finds a pale young man who charms her.
At the Vergy estate, Julien imposes on himself the duty of taking his mistress's hand under the linden tree and, after a trip to his friend Fouqué's house, who offers him a partnership in the timber trade and is refused, becomes her lover. The passion, at first made of vanity and ambition, becomes true love. When the youngest son falls ill, Madame de Rênal sees in the fever a divine punishment, and the maid Élisa, whom Julien rejected, denounces the affair. An anonymous letter reaches the mayor, and Madame de Rênal manages to divert her husband's suspicion onto his rival, the director of the poorhouse, Valenod. But the scandal grows, and Abbé Chélan, Julien's protector, orders him to leave for the seminary at Besançon.
At the seminary, Julien concludes that being first in one's studies is a sin and that a face of blind faith is worth more than learning. Isolated from the three hundred and twenty-one classmates, he finds support only in the director, Abbé Pirard, who appoints him tutor for the New and Old Testaments. Julien shines in the examinations, but an examiner tied to the vicar general Frilair sets a trap for him. When Pirard leaves the seminary, he recommends Julien as secretary to the Marquis de La Mole, a powerful aristocrat in Paris. Before leaving, Julien returns to Verrières, enters before dawn by a ladder into Madame de Rênal's room, and spends the day hidden, until he flees under gunfire.
Book II
In Paris, Julien settles into the La Mole mansion and becomes the marquis's trusted secretary, who sends him to London and gives him a decoration. In the library and the salon, he meets the marquis's daughter, the haughty Mathilde de La Mole, who is bored among the suitors of her class, the Marquis de Croisenois and the others. Fascinated by the memory of an ancestor beheaded and by anything that recalls heroic grandeur, Mathilde decides that she loves Julien, writes him a declaration, and invites him to climb a ladder to her room. Julien climbs with a pistol in hand, suspecting a trap. Mathilde carries out her resolution to surrender herself, but soon regrets it and humiliates him, and Julien accepts the recipe of the Russian prince Korasoff: pretend interest in the Marechale de Fervaques and copy out ready-made love letters to her. Jealousy brings Mathilde back, and she surrenders completely and becomes pregnant.
The marquis, furious to learn that his daughter will be called Madame Sorel and not duchess, eventually relents, gives Julien lands in Languedoc, the name Chevalier Julien Sorel de La Vernaye and a commission as lieutenant of hussars. Julien already sees a future for himself when he receives the news that undoes everything: the marquis asked for information from Madame de Rênal, and her letter, drafted by her spiritual director and copied out by her, describes Julien as a hypocrite who seduces the most influential woman in each house in order to dispose of the master and his fortune. Julien rushes to Verrières, buys pistols and, during Mass, fires twice at the woman he loved most. She is wounded in the shoulder, but survives.
Under arrest, Julien declares the premeditation to the judge, repents only when he learns that Madame de Rênal did not die, and is taken to a tower in Besançon. He receives a visit from old Chélan and from Fouqué, who wants to bribe the jailer. Mathilde, dressed as a peasant woman, comes to save him, seeks out Frilair and obtains, together with the Marechale de Fervaques, the promise of a favorable jury. Julien, however, has lost his ambition and thinks only of Vergy, and refuses furiously to plead the jealousy that the lawyer suggests. At the trial, he speaks before a moved audience, admits the premeditation and says that they want to punish him for his origins. The jury, in which Valenod sits, finds him guilty, and the death sentence is pronounced.
In the condemned men's cell, Madame de Rênal reappears, begs him to appeal, and the two forgive each other; Julien signs the appeal. He is afraid of death for the first time, dismisses an intriguing priest, receives his father with his accounts and, little by little, accepts the end. He refuses to convert noisily in order to win pardon, and forbids Madame de Rênal to go and ask the king for clemency. On the morning of the execution he dies without affectation. Fouqué buys the body for the grotto on the mountain above Verrières, and Mathilde kisses Julien's head and accompanies the burial. Madame de Rênal, who swore to live for Mathilde's son, keeps her promise, but dies three days later, embracing her children.