If there is one thing that Castle had going for it was the amazing Castle cast. What's a writer without his muse? That was the basic premise behind Castle, starring Nathan Fillion and Stana Katic. The 2009-2016 ABC crime-comedy-drama received praise and accolades during its time on the air. The show followed New York writer Rick Castle (Fillion) shadowing the exploits of NYPD Homicide Detective Kate Beckett (Katic).