'Castle': On set of tonight's episode, 'Dead Pool'

My hours on the Los Angeles set of Castle were much like Richard Castle’s first time working at the police station: I’m a writer, was there by invitation, had no idea what I was doing, and every attempt I made to make myself look cool failed miserably.

I got the backstage tour while the team was hard at work filming tonight’s episode, “Dead Pool,” which finds Castle and Beckett investigating the death of a champion swimmer whilst Castle’s protégé (Brendan Hines) mulls about, putting the charm on Beckett. I didn’t get to meet Hines, which is just as well. I embarrassed myself quite enough without adding someone else to the mix. To be honest, my incident probably wasn’t as bad as my memory is leading me to believe — or it is and, like any trauma, my brain is blocking out the worst part. But here’s what I do know:

I tip-toed onto the set with my two escorts (exec producer Laurie Zaks and ABC publicity guru Chandler Hayes) around mid-day. This was my first set visit, so it was jarring to walk into the fake police station. Entertainment folk usually like to talk about how some of the magic is lost when you see things behind the scenes, but I feel like the magic is the creation of a world where there once was an empty studio lot. Color me fascinated — or easily amused.

In my attempt to take in the details (no coffee in the coffee cups) (the police station is green — was it always green?) (damn, the cop extras are tall) I missed one important thing: We were walking up to Jon Huertas, who plays Esposito. I wiped my nervously clammy hand on my dress and prepared to shake his hand, but was distracted when someone spun around in a twirly chair about a foot from me and rose — Nathan Fillion.

Farewell, composure.

Suddenly, I was in full-blown fan seizure. My shoulders rose to my ears, like a turtle trying to shield others from noticing its fanatic excitement with a shell of invisibility, but I still managed to stick out my hand frantically before he thought I was a freak. “Why, hello,” he said, while I’m convinced he was still in character as Richard Castle. “Oh my God,” I squeaked out in an octave I was unaware I could reach. “Hi!” Thankfully, Fillion didn’t notice my blushing, but ever the smooth individual, I outed myself as I felt as redness spread over my cheeks. “I’m sorry. I’m having a moment,” I said, turning my head away and fanning myself to try to regain composure. The damn blushing was completely out of my control. I think I blacked out because I didn’t hear a reaction, which I’m pretty sure was laughter.

Thankfully, I recovered enough to regain my sense of awareness, and, as one of my tour buddies claimed later, Fillion and Huertas turned on the charm. (I think it was to make me feel better about being an epic dork.) The pair proceeded to show me the poster they shot on Fillion’s iPhone for their fictional spin-off series, which (in their minds) would focus on their friendship — not Castle’s relationship with Beckett. Hopefully the photo will one day see the light of day — it is quite bromantic.

A few more tid-bits:

• ABC launched this “official” Richard Castle website today, which you’ll see in tonight’s episode.

• Seamus Dever (who plays Det. Ryan) was walking around in a ripped jacket. We investigated while on set — it’s because of an on-screen scuffle in tonight’s episode, not severe budget cuts.

• Beckett’s coat in tonight’s episode is gorgeous.

• When walking into the writer’s room, I got a peek at the finale. Okay, the back of my head did — because I was instructed not to turn around and look at the white board of secrets. The back of my head says there is a huge twist to come.

Follow Sandra on Twitter @EWSandraG