One year later, Charles Darnay is living happily in London making a living as a French Teacher.
One day, he calls upon the Manette's house to have a private conversation with Dr. Manette while Lucie and Ms. Pross are out.
Mr. Darnay professes to Dr. Manette that he, in fact, has a very deep love for Lucie.
Mr. Darnay tells Dr. Manette that he would never ever get between Dr. Manette and his daughter. He only wishes that Dr. Manette tell Lucie how he feels if Lucie ever expresses affection for him.
Dr. Manette believes that Mr. Darnay deeply loves his daughter and will attest to his love if Lucie should ever reciprocate. Upon reflection, Mr. Darnay wants Dr. Manette to know the truth about who he is and his connection to France.
Dr. Manette does not want Mr. Darnay to tell him his secret. Rather, he tells Mr. Darnay that if he does marry Lucie they can discuss Mr. Darnay's identity then.