TVGuide.com: What is Katherine’s goal this season?
Plec: She sets her sights on basically making sure that the Stefan [Paul Wesley] and Elena love story hits a snag. It’s going to be fun seeing Stefan and Katherine come up against each other. Obviously it’s fun to see Damon [Ian Somerhalder] and Katherine because there’s a lot of history there, too, but the triangle becomes the square.

Villain vampire Katherine, who once turned the Salvatore brothers into sexy undead fangers, has returned to Mystic Falls — and boy, is she ready to cause some trouble. Vampire Diaries executive producer Julie Plec reveals that while the boys will discover her true identity quickly — since there was that little mix-up in the finale when Damon kissed Elena, but it was really Katherine! — the love triangle will get even more complicated in Season 2. Get the scoop on the new season below:

TVGuide.com: Nina Dobrev will be taking on two characters at the same time in the new season, playing both Elena and Katherine.
Plec: Nina is one of the nicest people in the world, and she makes the joke that Katherine is Nina on a Saturday night. Nina on a Saturday night is definitely feisty, but by no means an evil, manipulative, horrible troll. For her to be able to play both the moral center and soulful, compassionate character, and then the narcissistic, selfish, manipulative, naughty minx is big for her.

Vampire Diaries: Get ready for the rise of Katherine

TVGuide.com: What is Katherine’s goal this season?
Plec: She sets her sights on basically making sure that the Stefan [Paul Wesley] and Elena love story hits a snag. It’s going to be fun seeing Stefan and Katherine come up against each other. Obviously it’s fun to see Damon [Ian Somerhalder] and Katherine because there’s a lot of history there, too, but the triangle becomes the square.

TVGuide.com: How long will it take Stefan and Damon to figure out it’s not Elena?
Plec: They both know within the first 15 minutes of the first episode. Damon realizes he was duped, and Stefan comes face-to-face with Katherine. The fun of it is how Stefan responds to the moment, as opposed to how Damon responded to the moment.

TVGuide.com: You spent all of Season 1 leading up to Founders Day. What is the arc of Season 2?
Plec: What I loved about what Founders Day gave us is that we had this small town that was building up to its big anniversary, and the long arc of the show is that history repeats itself. We’re going to do something like that this year, but we haven’t landed on exactly what it is.

TVGuide.com: What came with the decision to kill off vampire Anna (Malese Jow) in the finale?
Plec: That is something, believe it or not, that Kevin [Williamson] and I never faltered on. We introduced the character knowing that her exit would [have] the most profound impact on Jeremy and Damon. For Damon, it was a glimpse of his humanity in that moment — he wanted to help her. We definitely knew she was there to make our heroes grow to a new level. We did it from a pure place and did it for a real reason.

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TVGuide.com: Jeremy (Steven R. McQueen) is now so immersed in the vampire world, so what will we see for him this season?
Plec: We refuse to say what happens to Jeremy other than the fact that he’s “alive.” Regardless of that, the most important thing for Jeremy is that he’s going to come out the other side of this with a much, much deeper and much stronger sense of himself. He’s going to be asking what his purpose is on this planet, so to speak. It’s all because of all the loss: parents, Vicki, Anna, and then his own desire to end his own human life.

TVGuide.com: How close will you stay to the novels as you carry on?
Plec: The deeper we get into the series, ironically, the more we’re going to be taking from the books. That’s cool because we strayed so far so quickly, just by definition of trying to shape a good story in the right way for television. To find ourselves naturally returning to the source material and the villains that you met, it’s kind of awesome.