The Clique of Gold by Emile Gaboriau

Generally it is in novels only that unknown people suddenly take it into their heads to tell their whole private history, and to confide to their neighbors even their most important and most jealously-guarded secrets. In real life things do not go quite so fast.

Long after the old merchant had left Henrietta, she lay pondering, and undecided as to what she should do on the next day. In the first place, she asked herself who this odd man could be, who had spoken of himself as a dangerous and suspicious person. Was he really what he appeared to be? The girl almost doubted it. Although wholly inexperienced, she still had been struck by certain astounding changes in Papa Ravinet. Thus, whenever he became animated, his carriage, his gestures, and his manners, contrasted with his country-fashioned costume, as if he had for the moment forgotten his lesson. At the same time his language, usually careless and incorrect, and full of slang terms belonging to his trade, became pure and almost elegant.