It may have begun with murder but Kate Beckett had a back story and Richard Castle was intrigued. As Castle said, "The point is, there's always a story. You just have to find it." From the moment he profiled Detective Kate Beckett while they read fan letters from his crazy fans, we were hooked. Beckett looked shocked and a little mortified by how close he got to her story. To his credit, Castle looked chagrined that his attempts at guessing her history seemed to cause her pain. For fans, it was the start of a complex and provocative relationship of which we could never get enough.