nathan fillion jonathan frakes castle blog 'Castle'   The 'Final Frontier': First look pics of 'Star Trek's' Jonathan Frakes directing Nathan FillionGet ready to geek out, “Castle” fans — and Trekkies!

Jonathan Frakes, who famously played Commander Will Riker on “Star Trek: The Next Generation,” is directing an upcoming episode.

In “Final Frontier,” airing Nov. 5, Castle (Nathan Fillion) and Beckett (Stana Katic) investigate a murder at a sci-fi convention. That’s familiar territory to both Frakes and Fillion, who have made a number of appearances at Comic-Con and other geek gatherings.

Fillion, of course, is a fixture in the Whedonverse, starring as Captain Mal in “Firefly” and Serenity,” Captain Hammer in “Dr. Horrible’s Sing-Along Blog” and recurring on “Buffy the Vampire Slayer.”

Check out the behind-the-scenes pics of their shoot for “Final Frontier” — and Castle and Beckett’s mission to explore strange new worlds.

“Castle” airs Mondays at 10 p.m. on ABC.

PHOTO GALLERY: “Castle” visits the final frontier

Posted by:dmoorhouse