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Silas (Paul Wesley)
The face is familiar, but it's a totally new role for Wesley, who's now also playing the 2,000 year old immortal who quickly returns to Mystic Falls. ''The fun of Silas is much like season 1 Damon [Ian Somerhalder] in that he's up to something and no one can quite figure out what it is,'' exec producer Julie Plec says. ''Specifically for Damon, it's driving him crazy because it's like the tables have turned: If you remember in season 1, Stefan was always saying to Damon, 'What are you up to?' and Damon's like, 'That's for me to know and you to....' Silas plays the same little tricks on Damon, so it's up to Damon to get to the bottom of what Silas wants, what he's doing to get it, how it's gonna impact all of them, and ultimately how they can put a stop to it.'' Wesley agrees that Silas is fun: ''Silas definitely sees Damon as being beneath him, on every level — experience, knowledge. Damon has always been the one to be the smartass who outclasses everyone else. So it's nice,'' Wesley says. ''I'm getting my revenge for playing droopy, sad Stefan for five years.''
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Nadia (Olga Fonda)
The mysterious badass Czech beauty follows Matt (Zach Roerig) home from his steamy summer romance abroad with Rebekah (Claire Holt) in the season premiere. ''What she is, is the big mystery. She seems like some single moment that they left behind in their European whirlwind, and when she appears, she indicates that there's more to her than meets the eye,'' Plec says. ''Between her and Silas, we definitely have our hands full in Mystic Falls of people causing trouble.'' Bonus tease: ''People should be looking forward to everything with Matt [this season], we just can't say anything about it,'' Plec says. ''Matt's got a good story line this year. It begins with a steamy, sexy tryst in Prague, and just goes from there. Our little Matty boy had a good summer.''
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Jesse (Kendrick Sampson)
As exec producer Caroline Dries says, ''The girls go to college, and they don't just go to college to study and learn. They go for the boys.'' They meet human student Jesse in the premiere. ''He begins as just someone who finds our darling Caroline Forbes [Candice Accola] very interesting and attractive. And she, of course, is remaining true-blue to Tyler [Michael Trevino] who hasn't quite managed to show up to college yet,'' Plec says. ''She's trying to hold him off without hurting his feelings, but he's very sweet and very smart and very tempting.'' He's also something else: ''As we get to know him, he opens the door to a bigger mystery that's happening at the college,'' Dries says. ''He becomes engrained in the supernatural mythology there.''
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Dr. Wes Maxfield (Rick Cosnett)
You'll recall that Whitmore College is where Bonnie's Grams (Jasmine Guy) taught, as well as Professor Shane (David Alpay). So you can understand why Elena (Nina Dobrev) and Caroline might think this brilliant, young, hot microbiology professor has something to hide when they work their way into his advanced class trying to solve a mystery in episode 2, and he, in Plec's words, ''calls them out instantly as not belonging, embarrasses them, and sends them slinking away.''
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Tessa (Janina Gavankar)
''Similarly to Nadia, she comes in to our world very clearly not who she seems,'' Plec says of the exotic beauty who makes her first appearance in episode 3. She comes to Mystic Falls looking to rekindle an old flame. ''Part of the mystery is trying to get to the bottom of who she is, what she wants, and why she wants it,'' Plec says.
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Aaron (Shaun Sipos)
Introduced in episode 5, the human student with a tragic backstory that rivals Elena's will become a genuine friend to her. ''Internally, we like to call him the Jordan Catalano of Whitmore,'' jokes Plec. ''Though it is just a friendship, it's one of those deep friendships that could be seen as threatening to boyfriends. But we thought it would be a really great opportunity to bring a new person into Elena's life who would legitimately be somebody who could fill a void of a lot of the friends and relatives she's lost over the years, somebody that really gets her in addition to her Salvatore boyfriend.''