Monday's Castle has already made headlines because of the return of James Brolin as Castle's mysterious CIA agent father Jackson Hunt. But based on our exclusive first look at the episode (10/9c, ABC), there may be a much more exciting reason to watch.Nathan Fillion ) and Beckett (Stana Katic) are deep in discussion about when they should schedule their upcoming wedding. Unfortunately, nearly every time of year that comes to mind yields some sort of conflict. But, noticing the couple's stress level, Martha (Susan Sullivan) drops a suggestion we could totally get behind. Click play below to hear Martha's bright idea and to see Castle and Beckett's (hilarious) reaction: However, the pending nuptials between Castle and Beckett could hit another snag in Monday's episode thanks to the aforementioned return of Castle's spy daddy. "I think that character adds a lot to the Castle mythology," creator Andrew W. Marlowe tells TVGuide.com of why now is the time to bring Brolin back. "I wanted him to make an appearance while our couple was engaged and give a little commentary on that. And we give Beckett a chance to meet her future father-in-law. I wanted the audience to be able see her reaction to who this guy is."