At the beginning of the novel, the innocent Charles Darnay is being tried in England at the Old Bailey for treason. Sydney Carton gets him acquitted, and he meets Dr. Manette and Lucie Manette, who reluctantly testified against him. He falls in love with Lucie and marries her, but he has to tell her father his secret: He is of the same French aristocratic family that imprisoned Dr. Manette. Darnay is determined not to continue the cruelty practiced by his ancestors but to treat people with compassion. Later, Darnay is imprisoned in Paris for being an aristocrat despite having renounced his title. Saved by Dr. Manette, he is rearrested—this time for murders committed by his father—and saved from the guillotine by Sydney Carton.
Sydney Carton, a lawyer who drinks heavily, happens to look enough like Charles Darnay that he saves Darnay from trumped-up treason charges. He becomes reluctant friends with Darnay because he is in love with Lucie Manette, but he knows he cannot have her. Carton's failing is that he has such terrible self-esteem that a simple friendship with Lucie is not enough to help him change his life for the better. But his love for Lucie is so strong that he vows to do anything for those she loves, so that she can have a good life. In the end, he sacrifices his life to save her husband from the guillotine.
At the beginning of the novel, Lucie is only 17 and has been told by Mr. Lorry, her guardian and adviser, that her father, whom she believes dead, has been released from the Bastille and is living in a garret in Paris. She brings him back to London to live with her. As the novel progresses, Lucie is the "golden thread" who ties together nearly all the other characters. She marries Charles Darnay, becomes friends with Lorry, and is loved unreservedly by Sydney Carton. Her goodness and her connection to Darnay make her a target for Madame Defarge, though Ernest Defarge believes she should be spared. Miss Pross is jealous of anyone who takes her away and yet will also do anything for her. And Dr. Manette considers her his angel of mercy.
When the story begins, Dr. Manette is a frail former prisoner who can do nothing but make shoes all day long. He is rescued by his daughter, Lucie, and once he is living with her, becomes a stable, loving father and solid friend—unless something reminds him of his time in prison. Even though Darnay is the nephew of the man who imprisoned him, Dr. Manette accepts Darnay into his family for Lucie's sake. He is willing to fight for Darnay's life, using every connection he has to save him from prison and certain death.
Mr. Jarvis Lorry
Mr. Jarvis Lorry is the one who discovers that Dr. Manette is actually alive and has survived his imprisonment in the Bastille. As the financial adviser to the family and Lucie's guardian for financial purposes, Lorry tries to keep their relationship professional. However, he can't help but get personally involved, and his ability to do business in both London and Paris gives him leeway to go above and beyond the call of duty for Lucie, Darnay, Carton, and Dr. Manette. His messenger even serves as a sort of guide and guard for Miss Pross, Lucie's governess. For Mr. Lorry, the Manette family and all who are connected with them are like family.
At the beginning of the novel, Monsieur Defarge seems to be an ally of Dr. Manette, his one-time employer. Defarge has stepped forward to give the doctor a safe place to stay after he is released from the Bastille. He also helps Lucie and Lorry take Dr. Manette out of the garret above the shop and get him out of Paris. However, as a leader of the revolutionaries, Monsieur Defarge cannot simply stand by and allow Charles Darnay to come back to Paris without any consequences, regardless of the fact that he is now Dr. Manette's son-in-law. Defarge is one of the people who denounces Darnay in court and brings forth Dr. Manette's letter denouncing Darnay as well. He stops short of being thoroughly vindictive, however, by saying he thinks it enough to punish only Darnay, not his wife and child.
Madame Defarge is admirably strong in her determination to fight for the revolution, but she is also vindictive and cruel. Once crossed, she has no mercy whatsoever. She stands by saying almost nothing and knitting, but she is the one who ultimately decides if someone will be executed or not, knitting that person's name into the long, otherwise purposeless piece of fabric she creates. Anyone connected with the aristocracy in any way is an enemy of hers, and anyone connected with the death of her family is condemned to die.