Spoiler a 4. évadról

 They're both going to have an opinion on how to help Elena. Stefan's method was very successful for Caroline, and we'll see him trying to teach Elena, where Damon is taking the opposite point of view. We're going to have a lot of conflict attached to those opinions.

We were heading toward the end of the road knowing that as a human, Stefan was Elena's choice. We also knew what was going to happen at the end of the episode. Elena is no longer a human when she wakes up and when the memories come back and when her whole life goes upside-down. Who's to say what that does to her? Who's to say what kind of person she becomes, and how that impacts who she loves and why she loves them? I'm not saying that's going to send her running instantly into Damon's arms, absolutely not, but it's going to cloud the issue even more.

The flashback to Elena and Damon's first meeting was a big shock for fans. In terms of your thought process there, what was the purpose of it? How did it drive the story?

It serves multiple functions. When Damon shows up in the pilot, he knows a lot about Elena, so there's always been a question about where he's been and what he was up to. How did he know all this? He clearly didn't just walk into Mystic Falls with his crow. He's been around too. We always said that one day we'd find out what he's been doing. It was us wanting to give Damon something to fight for. Ric is unbeatable, a jillion times stronger than Damon. Damon was a dead man, and Ric was relishing beating him, and Damon had nothing left to live for, having been passed over once again. It was just that slight little thing that she said to him, when she was just trying to take the sting off: "Hey, maybe if you and I had met first." She was just trying to soften the blow. But in reality, he had this memory that gave him the will to fight back. I love that moment, where Ric's about to drive the stake into him, and he's like "You know what? I'm not ready to die today."

When "Tyler" was saying goodbye to Caroline and talking about her beautiful future, was he already Klaus, at that point?

Yeah. We definitely were hinting at that with the "you're beautiful and you'll have a great future" line. That was a classic Klaus-Caroline line, so we wanted to give a little hint there. All that smooching and all that emotion wasn't Tyler at all, in fact, was Klaus. 

Before we see him return to that body, is he going to have a little fun being Tyler?

Yep. He's definitely going to prolong his stay, at least in the first episode, due to circumstance. Whatever goes down between Caroline and "Tyler" in the first episode will actually be happening between Caroline and Klaus, so we'll have some fun there.

I know you said Stefan and Elena will definitely make a go of being in a relationship again, but outside of that, where is Stefan's head right now? How is he looking at the choices that he made? He looked absolutely wrecked in that final scene.He was destroyed for so many reasons. Meredith had already broken the news to him, so in that moment of lying over Elena's body, he was mourning her as a human and realizing that ultimately he was unable to save her from the one thing she never wanted, which was to be a vampire. That's going to weigh on him really heavily and it's going to piss Damon off like nobody's business, that Stefan saved Matt instead of Elena. Stefan had a big burden in that moment and what he had to do was be true to Elena. It's like choosing to take someone off life support because it was their wish or to keep them on because you can't let them go. It was what she wanted, and Stefan, if nothing else, has always been able to let her make her decision. If, as a vampire, she starts to make the wrong decisions, then we'll see a shift in Stefan and how he feels about helping Elena through things. I think we'll start to get a glimpse at the different sides of Stefan in a relationship, where it's not going to be all peaches and cream and love and unconditional, unwavering support of Elena's decision. Elena is no longer Elena.

Would you say that the love triangle will be stronger than ever next season?
Yes. I say that at my own peril, but yes. People can get frustrated by the love triangle, people can find it grating or whatever, but the premise of the show is two vampire brothers and their love for the same girl. That's where we started and it's always going to exist in the landscape of "The Vampire Diaries." Some years it'll be more in the forefront than other years, when it's delicately laid in the background. Elena becoming a vampire will make it fresh. It changes things, and makes us ask new questions. It makes things a lot deeper. It's all part of this process of growing up. As our characters are working toward graduation and all kinds of life decisions -- do I go to college, do I leave my hometown, is my high school boyfriend going to be my college boyfriend -- all those life things, it's all going to be supported where Elena is with Damon and Stefan.