SAN DIEGO - ABC invited the Comic-Con crowd to check in to "666 Park Avenue." The spooky and soapy new drama will follow "Revenge" on Sundays this fall. But it's the show's genre premise -- a luxury New York City apartment building that may or may not be a gateway to hell -- and a cast led by "Lost" icon Terry O'Quinn that made it fit for the Con.

After a screening of the pilot (which seemed to play well in the only partially full room and previously screened during Wednesday's "preview night"), TV Guide magazine's Rob Moynihan moderated a panel discussion with stars O'Quinn, Vanessa Williams, Rachael Taylor and Dave Annable, plus executive producers David Wilcox ("Fringe") and Matthew Miller ("Chuck").

Although it's clear everyone involved is still figuring out key elements of the show ("They're saying nothing, you guys!" Taylor jokingly exclaimed at one point), they did share a few notable details:

1) Terry O'Quinn and Vanessa Williams don't know much about their characters yet

"I've only seen as much of Gavin as you all have seen," O'Quinn told the crowd after the pilot screening. "When you do television you don't get things too far in advance. He seems at the moment purely evil -- he would not slow down on the road for a child in a baby carriage. Maybe we'll find out a few more levels to him, I hope so and expect so." He later added: "Does he work for the devil? Is he a victim, a prisoner, has he made a deal of his own? Those are all questions I have and I hope we spend a long time answering them."

"I guess I'm Mrs. Evil," Williams speculated about her role as O'Quinn's mysterious wife. "It seems like we're in cahoots and we're trying to seduce this lovely couple [played by Taylor and Annabel] into living the lifestyle we are."

One of the few people who may have the answers wasn't spilling. Wilcox simply said: "It'll take a long time to figure out who this guy is and I think he'll surprise the hell out of you."

2) The show's structure will be more than just terrorized tenant of the week

"Episodes will have a self-contained beginning, middle and end, but it will hopefully feed a bigger story of the show," said Miller. "I think the idea is to take the core group of series regulars and see what they're going through as well as blending these storylines of people making a more accelerated deal with the devil, so to speak."

Wilcox added that viewers shouldn't expect the same thing every episode, "We don't want the show to be formulaic. When the show becomes formulaic we've failed. I hope you're constantly surprised, that's how we're approaching our storytelling."

3) Rachael Taylor is excited at the prospect of a weekly horror series

In the pilot, Taylor's character uncovers some of the building's more unsettling secrets, and expects there will be plenty more to follow. "I think there's gonna be a lot of me on the set all alone at three in the morning fixing a washing machine that's gonna end in something really creepy. It's an incredible opportunity for a young actress, different from anything I've done in my career so far, to explore possibly terrible things happening to characters we love."

4) "666 Park Avenue" is inspired by a novel, but the show isn't planning on playing by the book

When asked if anything after the pilot will come from Gabriella Pierce's book of the same name, Wilcox answered "Probably not. I think this show is taking on a life of its own. We're digging into these stories and following these characters where they go. They're surprising us."

5) They don't actually film on Park Avenue

Williams revealed the shooting location is the Ansonia building on New York's Upper West Side. The location has previously appeared on screen in "Single White Female" and "Hannah and Her Sisters" and Annable noted he was excited to learn Babe Ruth once lived there.

6) This was Terry O'Quinn's first Comic-Con

Incredibly enough, the man who was John Locke never made it to Comic-Con before this year. "I'm sorry I missed you all during 'Lost' but I'm glad we got to catch up now," O'Quinn told the crowd. Making his debut even sweeter: Williams led the audience in a chorus of "Happy Birthday" two days in advance of O'Quinn's big day.

"666 Park Avenue" premieres Sundays at 10 p.m. ET this fall on ABC