So what happens when a network goes to Nathan Fillion and say, hey we got a show where you get to be a writer who's also a detective.  Well of course that be enough to attract his attention. Add the name Rick Castle and costar Stana Katic as Kate Beckett and we have Castle.  Airing March 9, 2009, it follows Rick Castle, a big time mystery writer who just killed off his main character  Derek Storm.  When he gets called in questioning by Beckett, he learns that someone is killing by copying his books.  So of course he helps catch the bad guy and gets the hots for Beckett in the process.  With his connections with the mayor he gets to follow her around for idea's and we get a series. The 3rd season began airing Sept. 20th, 2010. The show is on Monday night at 10pm EST on ABC.