ABC's press release for the episode:
When a body is found at a sci-fi convention, Castle and Beckett are warped into the heart of fandom -- a world of egotistic celebrities, diehard costumed fans and enough drama for two galaxies, on "Castle."
Armin Shimerman ("Star Trek: Deep Space Nine"), Ed Quinn ("Eureka"), Christina Moore ("True Blood"), Erin Way ("Alphas") and Chris McKenna ("One Life to Live") guest star in this episode, which is directed by Jonathan Frakes ("Star Trek: The Next Generation").
Additional guest stars include John Bobek, Melinda Y. Cohen, Jeff Galfer, Channing Nichols and Erik A. Williams.
"The Final Frontier" was written by Kate Sargeant and directed by Jonathan Frakes.