AnonymousRe: "A whole new chapter in crime solving." Chapter is being used to describe the beginning of something new, usually a new time in a person's life (ie. going to college/university). Here it's Kate's new partnership with an author. And being an author creates a double meaning here since he writes chapters of books. Get it? Hope that helps.
oh now it clicked.. something’s wrong with me o_0 thank you for caring to read and write! it’s so nice and very attentive <3