Castle, as a result of its male lead—Firefly’s Nathan Fillion—has an established history of geek referencing. Usually, these references are winks at itself: Richard Castle dressing up as Malcolm Reynolds for Halloween (although he identifies as a “space cowboy” rather than as Mal), Kate Beckett referring to a party as “shiny,” Martha asking Castle (with great incredulity) “You haven’t heard of the Serenity?” and appearances by Fillion’s old shipmates Adam Baldwin and Gina Torres.

But it goes a bit deeper than this. Fillion, himself a mammoth geek, has made Richard Castle into one as well. The mystery writer collects toys, is an avid gamer, and has a full-size Boba Fett in his bathroom. In an industry where actors try hard to be taken seriously – and geek shows are rarely seen as serious acting – Fillion has stood out as an unapologetic advocate for geeks everywhere.

And he’s not alone. Time was when actors who starred in geek cult shows (because those two things used to be synonymous – all geek narratives were cult) were embarrassed by their work on those shows and actively ran away or made fun of them. In 1986, William Shatner went on Saturday Night Live and told assembled fans to “Get a life.” Before that, the title of Leonard Nimoy’s I Am Not Spock was seen as a similar attack on fans (and their supposed inability to tell fantasy from reality). And it’s not even a thing of the past now. My husband shook Brent Spiner’s hand at a con last year and Spiner joked afterward, feigning injury to his hand. When Chris responded in the same joking manner, “Hey, I can’t hurt you; you’re Data,” Spiner dropped the humorous tone and responded with disgust, “I am not Data!”.

But somewhere along the line, things changed. Maybe it’s because geek has been making its way into the mainstream. Maybe it’s the fact that people who grew up watching the original Star Trek or Doctor Who are now making the new versions. But many of the actors on these shows have a very different attitude towards those narratives and the fans. Rather than bitterly (and often silently) sitting at autograph tables at cons, begrudging every person paying money for their signature their time because they never did anything after Space 1999, we have James Marsters calling his fans “the beautiful freaks” and going out of his way to connect with them, Wil Wheaton refusing to charge for autographs at all and living his own life as the consummate fan, and of course, gamer, Twitter-addict, and evidently fan scavenger-hunt-arranger Nathan Fillion.