From Sci-FI Wire.Elizabeth Mitchell, who joined the cast of Lost this season as Juliet, told SCI FI Wire that the next new episode will feature a flashback that fills in the backstory of her character. "I thought it was in its own way simple, because it's concise," Mitchell said in an interview at the Television Critics press tour in Pasadena, Calif. "But at the same time, there's a lot that's fleshed out there. And if you are interested in the character of Juliet, it's a nice one to watch because you learn so much more."
The episode, titled "Not in Portland," picks up where the midseason cliffhanger left off, with Jack demanding the release of Kate and Sawyer in exchange for saving the life of Ben, the leader of the mysterious Others, on the operating table. Mitchell said that the episode will help explain Juliet's motivations for joining the Others, as well as actions in the previous six episodes of season three.
"I think they're giving you an insight into what's happening, and they further develop what happens at the end of the episode, which is something we've kind of been waiting to happen," she said. "So that's how they kind of mix it in there. I can't really say anything more than that because I don't want to give anything away if you haven't seen it, ... but I do believe they further it. What happens to Juliet and what her experience is then kind of feeds into what she's doing and why she's doing it."
Mitchell also urged fans to remember that although her character seems nice, she may have an ulterior motive. "She did what she set out to do, which is break Jack," she said. "So yes, she's nice, but look what she did to him. I mean, she kept at him. So that's not particularly nice. Nor is it friendly to take a friendship and twist it so the other person cries. That's not, to me, very nice. However, there was obviously a reason behind it. If you take any good person and give them an ultimate objective that they have to fulfill, they're willing to do almost anything. What we might do for our children, what we might do to save a parent or save our loved one, we're willing to do almost anything. So that, to me, is Juliet." Source: SCI-FI Wire