“This is probably one of the more grown-up things Castle has done since becoming a father — and even in being a father, he’s not very grown-up about it. [But] fatherhood happens to you. Making a choice to be with someone for the rest of your life, that doesn't just happen. That is an adult choice you have to make. That is some growing up you have to do. So I wanted to treat it as though it was a serious thing for Castle.” ~Nathan Fillion on Castle's proposal.
Nathan Fillion - Wikipedia, the free encyclopedia - Caleb in 'Buffy', Richard Castle in 'Castle' - a mystery novelist who helps the NYPD solve crimes. On March 30, 2010, ABC announced that Castle had been renewed for its third season with a 22-episode full-season order. Castle was renewed for a fourth season on January 10, 2011, and for a fifth season on May 10, 2012.