Nathan Fillion is best known for his role as Richard Castle on the ABC television series Castle. In addition to his extensive television resume, Fillion had also appeared in numerous movies, starting with small roles in the films Blast from the Past (1999) and Saving Private Ryan (1998).
When the television series Firefly was prematurely canceled in late 2002, the show's cast, crew, and many fans were devastated. Whedon vowed to resurrect the series in some way, and Fillion played Captain Reynolds again in the feature-film Serenity (2005). Fillion followed this film with bigger screen leading roles in the horror-comedy Slither (2006) and the indie hit Waitress (2007). He took his first singing part (and cemented his cult appeal) as Captain Hammer in Whedon's musical Internet smash Dr. Horrible's Sing-Along Blog (2008).