Fans of CBS's new hit sci-fi thriller Under the Dome were treated to an advance screening of the fifth episode, followed by a discussion with the series’ producers and stars.

Based on Stephen King’s bestselling 2009 novel, Under the Dome centers on a small town in Maine that’s suddenly enclosed within an unseen barrier, cut off from the rest of the world. As the residents panic, one group tries to maintain order while searching for the truth behind the dome and a way to escape it. Just this week, CBS renewed the series for a 13-episode second season.

Following the screening, moderator Michal Yo (OMG Insider) introduced series creator Brian K. Vaughan, executive producer Neal Baer and stars Mike Vogel (Barbie), D (Julia) and Dean Norris (Big Jim) for a discussion about the episode and what fans can look forward to in the future.

With the show setting the record for the highest-rated CBS summer premiere since 2000, Yo asked what it was about the series that resonates so well with the audience.

"These three people and our incredible cast," Baer replied. "I think it's always about the characters first and foremost, and Stephen King created brilliant characters in the novel that we adapted for this series. So once you can get the characters going I think we can identify with them when they're trapped in a place and their secrets and coming out. So we want to know more about them."

Yo asked Vaughan how he became involved with the project, and what it’s been like adapting King’s work. Vaughan, already a big King fan, explained he became interested in the book after learning that his name had been dropped in its pages.

"So it's been very surreal to have gone from being a pop-culture reference to getting to talk to that actual character under our actual dome," said the acclaimed writer of Y: The Last Man and Saga.

Moving to the actors, Yo asked Lefevre what she thought about the sparks of romance between her character and Barbie.

"They have a long way to go, and I think they have a lot to talk about, but certainly there's something there that's very hard to deny,” she replied, “and I think the writers have done a great job of making sure that we stay true to the chemistry that's there and the journey's a good one. So we'll see."

Speaking of Barbie, Vogel shared a few hints about his character's secret past and how the residents of Chester's Mill will react when the truth finally comes out.

"Neal, Brian and the rest of the writing team have done such an incredible job weaving this push and pull that Barbie's gone through to what's put him in this town and his past secrets,” Vogel said. “It certainly complicates things more throwing Julia into the mix. There's a lot of accusations that are brought against Barbie but people are also going to have to look past a lot of the good that he's done while he's here and they'll have to reconcile both of them and we'll let them make their choice at that point."

Yo then put Norris on the spot, confronting him about his character's son and how far the apple fell from the tree.

"In an earlier episode you said, 'He's a chip off the old block,'" Yo stated. "He's psychotic. ... So my question is, is he getting these psychotic tendencies from you?"

"His mother's side, not me," Norris said.

Norris may or may not have been joking, but he did reveal that Junior's deceased mother will come into play.

Moving back to Vaughan, Yo asked what it was like to adapt the work of King and have the author call to make changes to characters.

"It was terrifying," Vaughan said. "I love the guy, and I knew that we wanted to do something different. But thankfully, he's just been so sweet and generous and encouraging. He told us when we first came up with this idea he wanted to do a story about a town that was trapped potentially for years under a dome but by the time he'd gotten to page 1,000 they'd only been in there for a couple of days."

"He said to use this ongoing television series as an excuse to take these characters to places I couldn't," Vaughan continued. "So we're just so grateful to have him on board and for him to be that thoughtful of a collaborator. It's a dream come true."

Throwing another question to Lefevre, Yo asked what it was about Julia that drew her to the character.

"In my own life I pretty much wear my heart on my sleeve, and the filter between my brain and my mouth is limited," Lefevre said. "I was really attracted to the idea of playing a character who had all those emotions, wasn't necessarily cold but could restrain it and play it close enough to the vest to be that sort of journalistic tendency of 'I have to get answers' and try to be pragmatic. And I think that's something that television needs. I think television needs a lot of strong female characters who aren't just reacting to the male storylines around them."

Yo also asked Baer about the stockpiling of propane in Chester Mills, and what kind of resolutions will be made in the first season.

"We promise that all of these secrets that are coming out will be revealed this season, so you'll find out what Big Jim relationship really was with the propane and with Coggins, who he just pushed against the dome, and Duke, and there will be some mysterious women coming to town," Baer said. "Well, they're not coming to town, they were trapped under the dome as well. You know we have 2,000 people there, so there are some people we haven't met yet, and so they'll be really crucial to unfurling this story."

Referring to the latest episode, Yo asked Norris why his character didn't immediately help Angie escape the basement where his son was holding her captive, and what Big Jim needed to figure out before freeing her later in the episode.

"He just couldn't figure it out in the moment," Norris said. "If he let her go she might reveal the secret, and that would look bad for Big Jim, and then when he realized they were all going to die he had a change of heart."

But while Big Jim may have shown mercy to the captive Angie, he had none for Reverend Coggins. Yo asked Norris if he thought dispatching the people of Chester Hills would become a regular thing for his character.

"No no no no, it's all sweet and poetic after this," Norris joked.

An audience member asked if the show had been edited in any way since moving from Showtime, where it was originally set up, to CBS.

"The script was written when it was originally at Showtime, but we hadn't shot anything till we moved it to CBS," Vaughan said. "Really, when it moved over, I was worried that we'd have to do some sort of watered-down version, but CBS has been great. ... It changed very, very little. Fewer naughty words maybe, but just as many brutal killings."

The next question fan asked how long Angie will be able to hang on to her freedom with Junior and Big Jim still around.

"Well, since they didn't die under the dome, she's there with Junior still," Baer said. "So I guess in the next episode you will see what happens to Angie."

Asking about the dome itself, one audience member wondered how deep the barrier extends underground, and whether it was actually a sphere.

"Well, we saw Junior go down in those cement tunnels, and those go down very, very, very deep," Vaughan replied. "So I don't know whether or not it’s a sphere, but it's certainly not something that our characters are going to be digging out of any time soon."

"But that will be revealed in Episode 7," Baer added. "Sphere or not?"

The next audience member asked Norris how it felt transitioning from a good guy on Breaking Bad to a bad guy on Under the Dome.

"It felt really fun, actually," he said. "Playing the good guy takes a lot out of you. It's a lot easier to play a bad guy."

Going back to the first episodes, another fan asked about the possibility of Jeff Fahey's character returning in some capacity.

"We don't know all the powers of the dome yet, do we?" Norris answered.

"That is true," Vaughan said. "We sort of went into that first episode to make you fall in love with a great character, and it's a great actor -- we love Jeff Fahey -- just to let everybody know that nobody is safe on this show."

"I think they did it on purpose so we would behave on set,” Lefevre added.

Having admitted to reading the novel nine or 10 times already, Vaughan’s appreciation for King’s work put him in an unusual situation, as he had to make changes to the story for television.

"I'm a Stephen King fan, and I've seen Stephen King adaptations where they change stuff and I'm like, 'Why did you do this! I loved it!' but Stephen King really encouraged us. He said, 'People have read my book already. I don't want them to be able to go to Wikipedia and know how our series is going to end. So give us some surprises.' So even if you've read the entire novel and you think you know where the dome comes from and what it's all about, you don't."

The final question centered on what the cast members would do if they were actually trapped under the dome.

"I would certainly find this guy, if he was there, and make sure he was the first to go," Vogel said, pointing at Norris. "It doesn't end well for others that don't."

Under the Dome airs Mondays at 10 p.m. ET/PT on CBS.