I have a summary that gives a little more detail, if you need it. Or, perhaps you can use some from each summary.

In 1775, Lucie Manette, thinking her father, Dr. Manette, is dead, goes to Paris and discover he's alive, having spent the last eighteen years in the Bastille. In 1780, Charles Darnay is found innocent of treason against England due to the efforts of his friend, Sydney Carton. Charles goes to Paris to see his uncle, the cruel Marquis Evremonde, and expresses his disgust at how his uncle and other members of the French aristocracy treat the poor. A year later, Darnay promises to reveal his true identity to Dr. Manette if he will allow Darnay to marry Lucie. In 1789, the French peasants storm the Bastille, beginning the French Revolution, and they kill as many aristocrats as they can. After his marriage to Lucie, Darnay goes to France, is arrested, acquitted, and then arrested a second time because of his relationship to the Evremonde family, a fact he's been hiding. A letter proves that Darnay's father and uncle were responsible for Manette's imprisonment to hide a crime one of them committed. Darnay is found guilty and set to be executed when he's rescued again by Carton, whose elaborate plan gets Darnay out of prison, leaving Carton to take his place for execution. Darnay escapes with Lucie and their baby, and Carton dies knowing his life finally has some meaning.

Dr. Manette, imprisoned for trying to expose the cruel aristocrats St. Evremonde, is released after eighteen years.  His daughter Lucie marries Charles Darnay, and the family lives happily in England and France.  At the start of the French Revolution, the peasant revolt against the aristocrats, it is revealed that Darnay is really a St. Evremonde who has renounced his family and taken on a new identity.  Convicted largely by a letter Dr. Manette wrote in prison, he is condemned to die. Darnay is saved by Sydney Carton, who dies in his place for Lucie, for whom he has long held an unrequited but true love.