Viewers are certain to geek out over Monday's Comic-Con-inspired Castle, but not all of the sci-fi nerds in the episode will be those dressed up for the convention.Nathan Fillion ) and Beckett (Stana Katic), meet Gabriel Winters (guest star Ed Quinn), the former star of the "unjustly" canceled sci-fi series Nebula 9. Since hanging up his boots (and tightpants?) as Capt. Max Richards (wink, wink, Firefly fans), Winters now spends his day appearing at conventions and therefore becomes part of the investigation when a superfan is murdered.But perhaps there is another superfan in the room in this clip. Just look at how Beckett lights up when Winters walks in the room. Does she have a crush on him? Maybe not, but Star Trek: The Next Generation star Jonathan Frakes, who directed the episode and knows a thing or two about obsessed sci-fi fans, confirms Beckett secretly flies her nerd flag.