Why does Fagin take an interest in Noah and Charlotte? What about their conversation confirms his interest?

Fagin listens to Noah and Charlotte’s conversation, which is about Noah’s desire to be a wealthy thief, and then enters the back room. Fagin tells them that if they are interested in that line of business, then they are in the perfect pub for it. Fagin tells them his terms, and offers them jobs with him, which Noah accepts.