First Look: ABC’s CASTLE starring Nathan Fillion (Video) November 6, 2008 Castle, News Take a first look at ABC’s new Midseason TV show, CASTLE, starring Nathan Fillion. The promo for Castle is pretty self-expanatory as to what the story is, but I have to say, how much do you love Nathan Fillion after watching the trailer? I am so excited for this show. Read all our Castle coverage here. Watch the trailer for Castle below.