Castle showrunners Terence Paul Winter and Alexi Hawley have confirmed that Jewel Staite will be the latest Firefly alumni to join Nathan Fillion on Castle. Jewel will appear in Episode 20, Much Ado About Murder and will play the director of a Shakespearean Broadway play whose lead is murdered. “There are some great scenes between her, Nathan and the boys. She came to play, she was really great.” Said Winter.

Source: TVLine