Meanwhile, the situation in France grows worse. Signs of unrest become evident when Darnay's cruel and unfeeling uncle, the Marquis St. Evrémonde, is murdered in his bed after running down a child with his carriage in the Paris streets. Although Darnay inherits the title and the estate, he has renounced all ties to his brutal family and works instead in England as a tutor of French language and literature.
The revolution erupts with full force in July 1789 with the storming of the Bastille. The Defarges are at the center of the revolutionary movement and lead the people in a wave of violence and destruction.By 1792, the revolutionaries have taken control of France and are imprisoning and killing anyone they view as an enemy of the state. Darnay receives a letter from the Evrémonde steward, who has been captured and who begs Darnay to come to France to save him. Feeling a sense of duty to his servant and not fully realizing the danger awaiting him, Darnay departs for France. Once he reaches Paris, though, revolutionaries take him to La Force prison "in secret,"with no way of contacting anyone and with little hope of a trial.
Doctor Manette, Lucie, and Lucie's daughter soon arrive in Paris and join Mr. Lorry who is at Tellson's Paris office. Doctor Manette's status as a former prisoner of the Bastille gives him a heroic status with the revolutionaries and enables him to find out what has happened to his son-in-law. He uses his influence to get a trial for Darnay, and Doctor Manette's powerful testimony at the trial frees his son-in-law. Hours after being reunited with his wife and daughter, however, the revolutionaries again arrest Darnay, based on the accusations of the Defarges.
The next day, Darnay is tried again. This time, the Defarges produce a letter written years earlier by Doctor Manette in prison condemning all Evrémondes for the murder of Madame Defarge's family and for imprisoning the Doctor. Based on this evidence, the court sentences Darnay to death and Doctor Manette, devastated by what has happened, reverts to his prior state of dementia.
Unknown to the Manette and Darnay family, Sydney Carton has arrived in Paris and learns of Darnay's fate. He also hears of a plot contrived to send Lucie and her daughter to the guillotine. Determined to save their lives, he enlists the help of a prison spy to enter the prison where the revolutionaries are holding Darnay. He enters Darnay's cell, changes clothes with him, drugs him, and has Darnay taken out of the prison in his place. No one questions either man's identity because of the similarities in their features. As Mr. Lorry shepherds Doctor Manette, Darnay, Lucie, and young Lucie out of France, Carton goes to the guillotine, strengthened and comforted by the knowledge that his sacrifice has saved the woman he loves and her family.