The TV series Castle is about the only thing running these days that demands “must-see” status for me. It’s admittedly a trifle, but truthfully that’s why I like it so much. I’m really damn sick of all the scripted dramas with no sense of humor and a grim, clenched-tooth fascination with how sucky everything is. A lighthearted 1980s-style detective show is the perfect antidote to all that self-importance.

Anyhow, because of our conflicting schedules and mutual interest in the show, The Girlfriend and I usually record it and then catch up on each week’s episode a few days after it airs. We watched this week’s episode on Tuesday. It was a good one that tied up some dangling threads from earlier segments (I suspect this would’ve been the show’s finale if it hadn’t been picked up recently for a full second season), but what really made us both sit up and notice was the preview of the next episode.

I caught it first, a glimpse of something familiar…

“Hey,” I said, “Does that look like Nathan’s Firefly coat?”

“It sure looked like a duster to me,” Anne replied. “You don’t think…?”

“Well, it is the Halloween episode. Maybe Castle is dressing up as… Mal?”

And then we both started grinning because it was so obvious, so likely, and so damn cool.

See, the star of Castle, Nathan Fillion, played the dashing space captain Malcom “Mal” Reynolds on the short-lived and much-lamented series Firefly. And Fillion is well-aware that much of his fanbase — and Castle‘s, too, I suspect — is composed of Firefly “browncoats.” Because of this, I’m certain, every episode of Castle to date has had some kind of little shout-out to the science-fiction lovers who have stuck by him through several prematurely canceled ventures and are now delighted to see him in something that seems to be working. And what do you think would be the ultimate shout-out? Well, how about… this?

If you don’t recognize the outfit, I’ll confirm it for you: Fillion is wearing the complete Mal costume, right down to the really big gun. This is really a brilliant meta-joke… and considering how even that lousy cell-phone photo has plastered a big, big grin on my face, I can’t wait to see how it works in the full episode.

Props to the always-interesting Adventureblog for spotting this…