"CSI: Crime Scene Investigation" alum Marg Helgenberger goes "Under the Dome" when the drama series, based on the Stephen King novel, returns for its third season on Thursday. 

This season, some residents of Chester's Mill will make it out, but among those still trapped is anthropologist Christine Price (Helgenberger), who was in Chester's Mill on a mysterious mission and got stuck when the dome came down. 

"Christine is definitely strong and tough, but her mannerism has a light touch to it," Helgenberger tells FOX411.  "She's complex. There are a lot of sides to her, for sure. But I would say, she doesn't handle anything by force. It's more this subtle manipulation. But she doesn't like to take no for an answer."

The producers are promising that by the end of the season, we will have answers to the majority of the questions that have been raised in Season 1 and 2. But even as mysteries are solved, new questions will arise as the townsfolk face additional calamities -- some of which Christine may be responsible for.  

One of those opposed to Christine is -- no surprise -- Big Jim (Dean Norris), who has his own ideas on how things should be run under the dome.

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"We just did one episode together where we were in a large bird cage together, and it was really interesting because we couldn't touch because there was a divider," says Helgenbeger, who knew Norris from a guest starring role he had on "CSI." "Those situations are always kind of interesting when you can't touch and you're trying to make contact and have an intimate moment, but you have a cage between you."

This isn't Helgenberger's first go-round with Stephen King. In 1993, she starred with Jimmy Smits in ABC's miniseries "The Tommyknockers," in which the residents of a small town in Maine come under the influence of a UFO.

"I was in that miniseries 22 years ago, and, in fact, there are some things in 'Under the Dome' that reminded me of that," she recalls. "We shot that in New Zealand, and the town reminds me of Chester's Mill, as do some of the characters. Stephen tends to have a lot of similar themes in his books."

After "Under the Dome," Helgenberger, along with William Petersen, will return to "CSI" on Sept. 27, when  the long-running series will end its 15-season run with a two-hour movie.

"I adore Billy," she says. "We had such a great working relationship, so that'll be a lot of fun. When he left the show, I just sobbed and sobbed and sobbed. I was so upset, but I understood why he wanted to leave. But now I'm looking forward to working with him -- and everybody else, too -- Jorja [Fox], George [Eads] and Eric [Szmanda]… I'm hoping that this will be a really nice, proper send off, not only for the show itself, but for the fans."

The two-hour "Under the Dome" Season 3 premiere is Thursday, June 25 on CBS.

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