Ian Somerhalder, Michael Trevino, Paul Wesley

As Vampire Diaries dives into the second half of Season 2, the impending vampire-werewolf conflict will culminate in the season's final full moon — which executive producer Julie Plec says will be filled with "bad, bad things." That's not the only trouble Mystic Falls will see. Get the scoop from the cast below: 

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The Vampire-Werewolf War: The conflict between the vampires and werewolves "is going from a simmer to a boil," Plec says. In the center of it all: star-crossed maybe-lovers werewolf Tyler (Michael Trevino) and vampire Caroline (Candice Accola). "The next few episodes take us down the road of what Tyler knows, what he learns and how it impacts his friendships with Caroline and Matt [Zach Roerig]," Plec says. Adds Paul Wesley: "There are unforeseen alliances."

Flashback Blood Fever: The series will flash back once again to when Damon (Ian Somerhalder) and Stefan were turned into vampires. "Stefan is very Damon-esque," Wesley says. "He's lost and he doesn't know what to do with himself. He's living in guilt, so he is just sinful and lustful. We get some blood addiction. We're going back to his days of heavy usage."

Uncle John's Return: To save Elena (Nina Dobrev) from original vampire Klaus, Stefan has sought out her dad (David Anders). "He has some information that we need to extract from him but we also don't know if we can trust him," Wesley says."We go back to her roots and we start to uncover some things." Adds Dobrev: "Her father comes home and is in cahoots with everyone. She doesn't care about him, so it's almost annoying." In addition, Uncle John will challenge the "system [Jenna] has built and how hard she's worked to really build a home for" Elena and Jeremy, Sara Canning says.

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Katherine's Still a Threat: Even though Katherine has been locked in the tomb, Dobrev says, "She's plotting her way out. She's a woman who likes to be in control and when she's not, she's not happy and that's not a good thing right now."

Bonnie's Witchy Friends: The new witches in town were revealed to be working with original vampire Elijah (Daniel Gillies). So are they good or evil? "We learn a lot more over the next few episodes about why they're with Elijah, what it is they want, what's driving them, what side they stand on and where they stand with each other as father and son," Plec says. "Their relationship gets really complicated and it really complicates Bonnie's life specifically as she learns more and more about them."

Elena's Fate: With Elena prepared to sacrifice herself — spoiler alert: she does die in the book series  — will Elena survive through this season? "As long as there is still a human life left for Elena to live, taking that away from might seem premature," Plec says. "It's an option for the series because it's a very important part of the books. The big questions are: When do we go down that road? When is it too soon? When is it the right time? I don't know actually if we have the answer to that, so it's something we talk about all the time."

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The Final Full Moon: Last season's arc drove towards the Founders' Day celebration. "This year, our signposts have been marked by the full moons and I know that we have one more full moon that will be upon us before we hit the end of the season," Plec says. "Bad, bad things are going to happen as a result of that full moon. We also have this impending ritual — the sacrifice that will break the curse of the sun and the moon. That's where we'll end our season."

Vampire Diaries airs Thursday at 8/7c on the CW.

(Additional reporting by Robyn Ross)