The author gives us a clear hint that Mr. Lorry's mission resurrects issues from his own past through metaphor.  He describes the gentleman's thoughts as he awaits dinner, noting that "his mind was busily digging, digging, digging, in the live red coals".  The phrase "live red coals" expresses the idea that the memories recalled because of his mission, whatever they are, are still sensitive and perhaps very painful.

As Mr. Lorry awaits the arrival of Lucie Manette and commences his explanations when she does come, he strives to appear calm and nonchalant, but his actions betray the turmoil he feels.  When Lucie is presented, he perceives "a sudden vivd likeness...of a child whom he had held in his arms" long ago, and when the vision passes, he "cast(s) a troubled look" towards the place where it appeared.  Mr. Lorry is troubled by the story he must tell Lucie; he says, "it is very difficult to begin", and is tormented by "indecision".  Once he begins his tale, he insists that he is not emotionally involved, reiterating that he acts in a business capacity only -"Feelings!  I have no time for them, no chance of them".  His nervous mannerisms contradict his protestations, however, as he "flatten(s) his flaxen wig upon his head...which is most unnecessary", and is "exceedingly disconcerted" when Lucie questions him on what he has said.