The narrator reflects on the strangeness of the human condition: how we are all mysteries to each other. No matter how close, we always remain alienated from each other by our unique individualities.
One of the main themes in all of Dickens's work is the search for mutual understanding and human sympathy.
Half asleep in the mail coach, Mr. Lorry dreams of wandering through the inner vaults of Tellson's Bank and finding everything safe. He also dreams that he "was on his way to dig someone out of a grave." In his dream, he sees a cadaverous man who has been buried alive for 18 years. Mr. Lorry asks the man if he cares to live, then also asks over and over if the man will "come and see her?" Sometimes the man cries out that seeing "her" would kill him, at other times that he must see her immediately.
Mr. Lorry's dream foreshadows Dr. Manette's situation. Lorry's questions about whether the man "cares to live" and whether he wants to see "her," link the idea of Manette's potential return to life with a woman, suggesting that it is love that will return him to life. The dream of digging up someone from a grave also foreshadows Jerry's other job as a grave robber.