Dickens refers to the Doctor's imprisonment twice in this chapter, first in the discussion between Mr. Lorry and Miss Pross and then in the Doctor's response to Darnay's story. Both incidents are reminders that the reasons behind the imprisonment are still a mystery ; the Doctor is keeping secret who imprisoned him and why. The Doctor's startled response to Darnay's story indicates that he may have left a clue to his imprisonment in the cell where he was kept.
Dickens also makes clear to the reader that Lucie serves as the emotional center of the novel. Earlier in the book, he described her as a "golden thread"running through the Doctor's life and keeping him sane. Similarly, in this chapter, Dickens states that "everything turned upon her and revolved about her,"suggesting that her sphere of influence extends beyond her father and encompasses all who come in contact with her. Lucie's effect on people indicates that she is the golden thread running through the entire novel. She possesses some quality that draws people to her and inspires them to be more than they are; for instance, her father has become more than a shoemaking prisoner, and Mr. Lorry has become more than a businessman. Similarly, Darnay and Carton both appear to be courting Lucie, demonstrating a desire to advance their lives from bachelorhood to marriage. As the book progresses, her influence on them will become evident in increasingly dramatic ways.
Making Lucie — a rather two-dimensional character — so central to the book may seem strange, but keep in mind that Dickens created Lucie to be an ideal rather than a real woman. She represents all that is good in humanity — innocence, kindness, faith, and hope — and she serves as a touchstone for other characters to find those qualities within themselves. Her premonition at the end of the chapter that she hears the echoes of the footsteps of those who will enter their lives, along with Carton's statement that crowds of people will be entering their lives, implies that these higher qualities of humanity will be challenged in the future.
