Richard Castle is the fictional protagonist from the ABC crime drama television series "Castle." The character on the show, played by Nathan Fillion, is a best-selling mystery novelist enlisted by the NYPD to help solve crimes.
After the character gained popularity, ABC and Hyperion Books began releasing real versions of novels Richard Castle wrote on the show, crediting the fictional character as the author. Seven novels have been released under the character's name, as of 2015, with each of them making it onto the New York Times Best Seller list. The third novel in the series, "Heat Rises," debuted at number one. The television series premiered on March 9, 2009.