The first person to visit Lucie and Charles after they return from their honeymoon is Sydney Carton. Carton apologizes for his drunkenness during past encounters, and asks for Charles' friendship. Carton declares himself a worthless man, but says he has a favor to ask: would Charles mind if he occasionally visited his house? Of course not, Charles replies.
The novel foreshadows that Carton, as the first to meet the married couple, will be especially important to Charles and Lucie's life as a family. For his part, Charles is just being polite, humoring Carton out of his sense of obligation to him.
At dinner that night, Charles comments to Lucie, Manette, Mr. Lorry, and Miss Pross about Carton's careless and reckless behavior. Later that night in their room, Lucie suggests that Charles was too judgmental toward Carton. She asks Charles to have faith in Carton, who she believes has a wounded heart but is nevertheless capable of doing tremendous good. Charles blesses Lucie for her compassion and promises to have more sympathy for Carton.
Unlike Charles, Lucie has a deep sympathy and compassion for Carton's pitiful soul. Even though she hardly understands his behavior, Lucie has faith. Her prediction about Carton foreshadows the incredible sacrifice that Carton will make for the Manette family.