This story first appeared in the April 5 issue of The Hollywood Reporter magazine.
It might be called Castle, but Fillion-verse could almost be another name for the show, considering all the wink-wink nods to the actor’s sci-fi and soapy past that dot the series. “There’s being a fan of Nathan Fillion, and then there’s understanding who Nathan Fillion is to his group of followers,” explains Castle creator/showrunner Andrew Marlowe. “The fact that he brought those folks with him, and they showed up and they were supportive to us, was great.”
Season 2, Episode 6, “Vampire Weekend”
Castle dons a brown coat, the signature garb of his Firefly hero, for his “space cowboy” Halloween costume. “When we were in the second season doing the Halloween episode, [writer] Terri Miller felt, ‘Why don’t you put Nathan in the Captain Mal outfit as a nod to all the fans?’ ” recalls Marlowe. “We had such a positive reaction, and Nathan is always game for a Firefly reference.”
Season 3, Episode 18, “One Life to Lose”
The show pays tribute to the actor’s One Life to Live soap-opera past and centers the plot on a murder with real daytime soap stars like Cameron Mathison.
Season 4, Episode 21, “Headhunters”
Fillion reunites with former co-star Adam Baldwin, who played the rough-and-tumble Jayne Cobb on Firefly, as Castle finds a new (temporary) partner in the tough-guy Detective Ethan Slaughter.
Season 5, Episode 6, “The Final Frontier”
Directed by Jonathan Frakes, Commander Riker on Star Trek: The Next Generation, this Comic-Con-themed episode is filled with insider nods, including guest-star turns by Eureka’s Ed Quinn, Star Trek: Deep Space Nine’s Armin Shimerman and Alphas’ Erin Way. “I’m a fan of good sci-fi: Star Trek, Battlestar, that Joss Whedon show ... ,” says Castle at one point.
Season 5, Episode 14, “Reality Star Struck”
The Real Housewives franchise gets a Castle spin in this episode featuring Gina Torres, the second Firefly regular to drop by.
Castle airs its 100th episode at 10 p.m. Monday on ABC.