For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Dickens makes this easy for us. He divides the novel into three sections. The first is "Recalled to Life." In it, Dr. Manette is… recalled to life. He’s released from prison and is cared for by his daughter.
Act II
Act II is otherwise known as "The Golden Thread." Its title refers to Lucie, who holds the entire family together. She marries Charles Darnay, a French aristocrat. Meanwhile, revolutionary activities are building in France.
Act III
In "The Track of a Storm," Charles is captured in France. The family rushes to save him, but in the anarchy of the new Republic any attempts to seek justice fail. Doctor Manette briefly rises to importance in the new regime; his power, however, isn’t enough to save Charles. Finally, Sydney Carton switches places with Charles on the morning of the latter's execution.