It's always nice when a literary series follows the cinematic version. If I didn't watch the show, I don't know that I would have finished the book but I liked hearing the voices of Castle and Beckett in my head and thinking about that character writing this book.
Heat is pissed off at Rook for the profile he wrote about her. But they run into each other again when the famous Cassidy Towne, gossip columnist, is murdered. Rook had been interviewing Cassidy and seems to know more about her than almost anyone, especially her extensive list of enemies. That list includes almost anyone famous in the upper echelon of New York, baseball players, chefs, and the like. The sex that's missing in the TV series (so far) is definitely available in this book.