Sunday's "Castle" panel Comic-Con International began with a special announcement from Richard Castle himself, in the form of a short video in which Nathan Fillion's character stumbled upon a murder. In a moment of typical exuberance, he pulled out his cell phone, snapped a picture of the body, and announced, "I'm going to Twitpic this!"
The video set up "The Mystery of the Fallen Angel" for fans, who were encouraged to follow "Richard Castle" on Twitter at @WriteRCastle to help solve the case.
Sunday's panelists included executive producer Laurie Zaks, series creator Andrew Marlowe, and actors Seamus Dever, Jon Huertas, Tamala Jones, Stana Katic, Nathan Fillion and Molly C. Quinn, who embraced the spirit of the convention so completely that she dressed as an Enterprise crew member from "Star Trek."
Moderator William Keck asked Katic what her character, Kate Beckett, was about to confess to Castle in the season finale.
"I'd like to defer to the writer and executive eroducer Andrew Marlowe," she said.
Before Marlowe could answer, Fillion broke in and said, "Say it in a sexy voice."
Marlowe acknowledged, "We're having fun with the romantic tension between them," but said, "You'll just have to tune in and see what we have in store, but it will be fun."
In a clever bit of cross-promotion, the second novel "written" by Fillion's character is called "Naked Heat" and will be available in September.
Keck asked Fillion and Katic to take turns reading aloud from the book. Amid catcalls and whistles, Fillion slowly read through one of the sexier passages in a voice that was a funny mix of William Shatner and the Old Spice Guy.
Actress Molly Quinn was asked about the unique father-daughter relationship between Castle and Alexis, and Keck wondered whether Quinn ever felt like she was Castle's mom.
"Well, Nathan and Castle's mom, actually," Quinn said.
Because of Nathan's role in "Dr. Horrible's Sing-Along Blog," Keck asked if there might be a musical episode of "Castle" on the horizon.
"I think we'd love to," Marlowe said. "Hopefully, you guys will support us on the air. It's more of a fourth- or fifth-season thing."
When asked if the audience would be introduced to Castle's father anytime soon, Marlowe said, "We like playing the mystery, so I wouldn't say in the immediate future, but we do have plans."
Fillion said his first choice to play Castle's dad would be Christopher Walken, and he performed a spot-on Walken impression for the audience.
Marlowe hinted that while it would not be solved this season, the show would be delving deeper into the conspiracy behind the murder of Beckett's mother.
Because of Fillion's adversarial chemistry with Neil Patrick Harris from "Dr. Horrible," one fan wondered if the actor might show up in an episode.
"The only thing holding Neil back, really, is his talent" Fillion said, adding, "He's got so much that, first of all, he's full of himself and he knows it, but it keeps him really, really busy."
Marlowe responded to this comment by throwing down the gauntlet: "I will challenge Neil to come on the show and we will write a role for him."
"Maybe for the musical episode," Fillion said.
Fillion handed out signed mementos to several audience members who asked questions. Fans received "double-rainbow makers," an autographed package of Oreo cookies and a few signed wristbands from some of the parties Fillion had attended that weekend. One lucky (or perhaps, not-so-lucky) fan received a container of Fillion's hair collected by the make-up artist on the show, which they had affectionately nicknamed, "Nate's bits."
Before handing over the container Fillion asked, "You don't practice voodoo, do you?"
One of the last questions was about whether or not there might be a Comic-Con-inspired episode of the show.
Creator Andrew Marlowe said, "It seems like a murder at Comic-Con or a murder at a sci-fi convention would be something that the 'Castle' universe would embrace."
The cast and crew of "Castle" further illustrated just how warmly they embraced Comic-Con by doing a special autograph session for 200 lucky fans chosen at random.