Well, without more context, it's difficult to say precisely. 'El turco' could refer to someone of Turkish origin in the context of the novel. It might explore cultural clashes or fusions if the story is set in a place where different cultures meet. It could also be a completely fictionalized account where 'El Turco' is just a creative name for a protagonist with a unique story.
I'm not entirely sure specifically about an 'el turco novel' as the name is rather general. It could be about a character named El Turco. Maybe it's a story set in a particular Hispanic or Latin American context, perhaps revolving around the adventures, relationships or the life journey of this character.