The Manettes have been summoned to court as witnesses for the prosecution in the trial of Charles Darnay, who is accused of treason.
Darnay, who has made several trips back and forth between France and England, is suspected of passing documents that listed his Majesty's forces and their destinations into French hands. The Attorney-General further accuses Darnay of being involved with "pernicious missions" during the war between Britain and America. This Charles Darnay is so accused because of the testimony of a "patriot" named John Basard, a man Darnay once hired as "a handy fellow." Basard testifies that Darnay has been involved in suspicious acts of providing English secrets to the French.
Then, Miss Lucie Manette is called to testify. When she is asked by the Attorney General about the man on trial, Miss Manette answers affirmatively that two French men came on board at Calais for the passage across the English Channel. Further, she testifies that some papers had been handed between them. Then, Miss Manette says that Darnay told her that he was traveling on business of a "delicate and difficult nature," which might get people in trouble, so he was using an assumed name.
The Attorney General asks Miss Manette if Mr. Darnay made any remarks about America. She replies,
"He tried to explain to me how that quarrel had arisen, and he said that so far as he could judge, it was a wrong and foolish one on England's part. He added, in a jesting way, that perhaps George Washington might gain almost as great a name in history as George the Third. But there was no harm in his way of saying this; it was said laughingly, and to beguile the time."
When Dr. Manette is called as a witness, he cannot identify Darnay as a passenger on the Dover stage or otherwise, explaining that he is newly released from prison, where he spent eighteen years.
Then a witness is called to verify that the prisoner Darnay boarded the Dover stage five years ago, along with "some fellow-plotter" in order to get out in the night, as a blind, at a place where he did not stay, from which he
"traveled back some dozen miles or more, to a garrison and dockyard, and there collected information."
When this witness is asked if he is certain that it was the prisoner, Darnay, the witness says he is certain. However, after the barrister, who has been staring at the ceiling passes a piece of paper to counsel, Mr. Stryver, the counsel, asks the witness to look over at a gentleman and answer if he does not think he and the accused look much alike.
...they were sufficiently like each other to surprise, not only the witness, but everybody present, when they were thus brought into comparison.
When the witness cannot verify which man is which, his credibility is brought into question. Mr. Stryver then exposes the "patriot" Barsad as "a hired spy and traitor." The evidence "warped" from the unnerved Miss Manette comes to nothing, and the prisoner, Charles Darnay, is acquitted of the charges against him after Stryver also exposes Basard as having been to debtor's prison.
The court scene is first introduced in Chapter 2 of the Second Book, "The Sight." In this chapter we learn that Charles Darnay is on trial for treason. Lucie and Dr. Manette enter the courtroom as witnesses against Darnay, though Lucie is struck with compassion for him. Chapter 3 elaborates the scene. Lucie is called as a witness because five years earlier she had met Darnay, who, at that time, told her he was traveling by a false name because his business was sensitive in nature. This testimony is one way that the prosecution is trying to prove that Darnay is guilty of treason, of working as a spy. The chapter concludes with the defense bringing in Sydney Carton, the near-identical doppelganger to Darnay. The case is dismissed.