Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

Who played Captain Jean-Luc Picard in the television series 'Star-Trek: The Next Generation'?
jean-luc picard

Which of the American Idol judges has been there for all 10 seasons?
american idol

In which novel by Dickens is Stephen Blackpool a power loom weaver in Josiah Bounderby's mill?

charles dickens