SPOILER ALERT: Do not read ahead if you have not watched the series finale of “The Vampire Diaries,” which aired on Friday, March 10.

Executive producer Julie Plec promised an “emotional experience” in “The Vampire Diaries” series finale, and that’s exactly what we got. Here, “The Vampire Diaries” co-creator breaks down the finale.

How does it feel to have your series finale fall on the same day as the “Buffy” 20th anniversary?

I didn’t even know that was happening until a few days ago. Somebody asked me about it and I was so surprised. It feels nice and poetic to the show, obviously. My love for the show had a happy influence in the choices made over the years on “Vampire Diaries.” I think Joss Whedon is a genius. And while I’m sorry to steal some of their thunder on their special day, I’m honored to be able to share it.

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Did you draw any inspiration from any particular series finales going into this? Any you revisited and thought, “that gets it right” or “we have to avoid this?”

The three finales that got talked about most often in our writers room over the year were: “Friday Night Lights,” “Six Feet Under,” and “Lost.” You could probably pinpoint the influence of each of those individually in the finale as we did it.

Caroline ends up being the only vampire left by the end of the finale, which makes quite a bit of sense, considering how much vampirism always suited her better. Was that an intentional choice or just happenstance?

Starting at the beginning of the season, when we were talking about how we were going to end the show and what each character’s ending would be, we started talking about legacy and what each character’s legacy was. And I had a moment in the room where I said, “Oh my God, she’s Eliza Hamilton. And her school is the orphanage.” And her legacy is to live on, even as she loses those around her.

“Who lives, who dies, who tells your story.”

“Who lives, who dies, who tells your story.” Caroline Forbes lives on to tell your story.

We talked about having to have the wedding in the penultimate episode, but now I’m curious to know what scenes you just had to have in the finale?

Oh gosh. It was very important that we get to have a beautiful final emotionally romantic moment — not romance in the way that you understand it, but an emotionally romantic moment — between Stefan and Elena. And a goodbye that did them service as a couple that we had loved so much. I was determined to see Lexi at the end and to indicate that Stefan’s peace involved reuniting with his best friend. Those are the two off the top of my head that were important.

What was your personal favorite callback to the past seasons in this episode? Katherine stealing Damon’s “dot dot dot” line from Season 1 was fun, but Lexi/Elena/Stefan’s car reunion as The Fray played felt like a gut punch.

Every time I see that [Stefan] moment, I am at my happiest and most tearful, because I just think that friendship was so beautiful. Lexi was such a potent character; that song means so much to Stefan and Elena, as it ended our pilot. And Kevin [Williamson] would argue with you Katherine didn’t steal Damon’s “dot dot dot” line — he must’ve learned it from her.

Where does the return of Tiki’s grandad fall on the callback scale?

Oh yeah, that’s my favorite callback!

There are probably only a handful of fans who remember Tiki’s grandad, so it’s quite the callback.

Here’s what’s so great: That almost ended up on a cutting room floor, that scene. Because I had to cut so many moments from the show and I’m a Twitter buddy with the person who runs the Tiki’s Grandad Twitter handle, and so she — I think it’s she — had tweeted me, sort of saying thanks for all the fun over the years and I said, “I’m so devastated. I had a cameo for Tiki’s grandad that just got cut.” And then, by the time we were done editing the show, that one little piece was able to get back in and I was so happy. So she doesn’t know that, so she’ll have a nice surprise tonight.

Can you say what else was cut?

Just, honestly, little sections and moments along the way. There were a couple of montage pieces of people walking and brooding, and that ended up on the cutting room floor. The farewell scene at the cemetery had each individual character laying down an item in memory of Stefan. Matt laid down his vervain bracelet, Elena laid down her necklace. You can see them all there in that last shot on the stump. But we had a much longer goodbye montage that went away. A lot of painful cuts, but nothing that takes away from the overall completion of the story.

Were Matt and his dad really planning to die with Vicki and Mystic Falls, assuming the hellfire engulfed the town? They were saved by the (figurative, not literal) bell, but that’s still pretty dark.

I think that they were intending to be the captain of the ship as it went down, like last men standing. They believed in Bonnie. They believed that what she was going to try to do could work. But there was a risk that they would also go up in flames. They’re not standing on the deck, waiting to drown — they just know that that’s a possibility if things don’t go well.

What was it like having Nina Dobrev back on set and getting back into that Elena and Katherine groove?

Nina jumped right back in. It took her all of about six minutes to be comfortable in both characters again. And it was a real delight. She came prepared, and she came emotional, and she came full of love and excitement and really made it a lot of fun for us. And gave that sense of “the party was beginning” as we came to an end; with so many returning faces, it was one big reunion.

When Katherine is going on about her diabolical plan, she points out that she had Cade wrapped around her finger from the minute she set foot in Hell and was the reason he went after the Salvatores in the first place. Was there ever any discussion/consideration to show how exactly Katherine got control of Hell? We know Katherine can charm anyone, but even the Devil?

When we started talking about Katherine being the puppet master, we loved the idea that she had shown up in Hell — which is the worst place in the entire universe — and somehow managed to Katherine Pierce her way out of suffering. And not just get out of suffering, but then ultimately charm, woo, manipulate the Devil himself. It just seemed fitting for her character. So had we had Nina Dobrev with the show for the last couple of seasons, it’s entirely possible we would’ve wanted to tell that story, but in absence of that opportunity, we’ll love the fan fiction.

Speaking of fan fiction, a lot will probably come out of the Damon/Elena happy ending. But how long do you think Damon and Elena ended up living in their rich, fulfilled lives together? Did they have children? Elena became a doctor, as planned, but what did Damon do with his humanity?

I have a lot of different versions of what they had together over the decades. Probably, for me, it’s influenced by the enthusiasm of the fandom to want them to have gone to [their loft in] Tribeca and raised their children before they came home to Mystic Falls. So, somehow that’s been embedded in my head, and maybe that’s what they had.

Can you tell me more about the Salvatore Boarding School for the Young & Gifted? How exactly are the young and gifted chosen? They probably can’t all be witches.

No [they’re not], but one of the small runners of this season that I really liked was this idea that, between Kai — who was just born wrong — and the Sirens, too, and even Cade, who were different and so terribly mistreated that they became villains. And the idea of intolerance and not creating a space for children who are different and could potentially go down a dangerous route if they’re not properly taught and cared for — it just felt like a nice, positive message for the future, whether it’s a future of more stories or just a nice button to this story. Certainly the idea of that — of raising somebody right in the face of extreme power — is very much what the fourth season of “The Originals” is all about.

You also directed this episode. What was the most emotionally draining scene to direct? Or even just the most difficult scene?

The most difficult day was the day in the tomb. It was an entire day in the tomb, and it began with a relatively simple scene between Stefan, Damon, and Katherine. But then it moved into that beautiful emotional scene between Stefan and Damon, the goodbye and the compulsion. Everybody was so dialed in emotionally for that scene, and the hours we took to shoot it were so powerful. And then we broke for lunch. I seriously felt like we were done for the day, like there was no more that we could possibly do. And yet we still had like an entire half-day of shooting and everything else that had happened in that tomb with fire bags, with knives, and blood syringes, and tunnels, and green screens. I was so spent after the first half of the day, emotionally, that it took me a couple of hours to get back in the right headspace for all the gag work. And the same thing happened with the AD and the DP, and we all just looked at each other and laughed about two-thirds of the way into the day, feeling like we had completely failed the second half of the day. We were just chasing shots in no particular order to get them, because none of us could get our heads screwed on straight.

There’s been a lot of debate this season and really in the series as a whole about accountability when it comes to vampires and their humanity switch. Here in the finale, Stefan addresses the fact that he really is responsible for his actions — like killing Enzo — even when his humanity was off as a vampire. Do you think that accountability is part of why someone like Stefan and Damon and even Vicki were able to find their peace? As opposed to Katherine, who would never take the blame for anything?

I absolutely do, and I think that we had a really delicate dance all series — but specifically this season — with the idea of holding our heroes responsible for their actions. … In the moment it was important that the audience didn’t turn against their heroes, so they could fall on the “well, Stefan was under the control of Ripper Stefan” or “Damon had his humanity off” or “the Devil made him do it” and we could fall back on those excuses. When all is said and done, if you are not willing to take accountability for your actions, whether you’re an addict or possessed by a demon, then you’re not being honest with yourself. And I think it was important for all of us that we acknowledge that, yes, the bloodshed and the damage done by our heroes was real and there’s a price to be paid for that.

Does Stefan’s statement in the finale about how he would never go a day without vervain officially make him the smartest human character in the history of the show?

It just means he’s learned his lessons from other people’s mistakes.

I know the Kelly Donovan/succubus thing comes up often when discussing dropped plots or ones the show decided not to do. Her return and tragic end in the penultimate episode makes me wonder: Are there any other specific storylines you wish you could’ve done but didn’t?

After eight years, we dug so deep into the well trying to find stories that we could do that I don’t know that I have any regrets about the ones that we didn’t. Maybe they’ll start flooding in in a couple years and I’ll wish we would’ve done nine years. Right now, I just feel like we told all the stories that we got in us.

Is there any character dynamic you wish we could’ve seen more of? I remember that, throughout the entire series, it was always kind of weird but fun to see Tyler and Elena share a scene. They had the Matt factor going on their relationship, at least.

Well, I’ll tell you: We realized over the course of many years that Tyler and Elena probably shared, all told, maybe 22 minutes of screen time. Which was weird when you think about it. And then there was somebody else, who was it?

There was one Caroline/Jeremy scene back in Season 1, which was also great but very unexpected.

Right! I mean, I imagine Candice and Steven probably shared about eight minutes of screen time. When you have an ensemble where characters pair off so easily, it becomes extremely isolating in the story world. You can end up with two actors who have not seen each other face to face all season long.

These characters started off in high school, meaning the audience in a way grew up with them (even though most of these characters spent time being immortal). But how does it feel for you and your growth as a writer and creator and showrunner and boss? Eight seasons of television is a long period of time.

Yeah, I mean I started as someone who wasn’t entirely sure she knew what she was doing. And I ended as someone who’s still not entirely sure she knows what she’s doing. But I have a lot more experience and season and a lot of mistakes that I’ve been able to learn from and a lot of success … and I feel like I’m coming out of it with a Master’s degree, and now I can go try to get my Ph.D.

What storyline do you feel most proud of? Or what do you think are the most memorable moments of the series for you?

I think I can hang my hat most on memorable characters. Katherine Pierce. Klaus Mikaelson. Kai Parker. Probably Elijah Mikaelson and Rebekah Mikaelson. Those characters really landed and really popped and obviously were so successful that some of them even launched their own show. And that was the most fun for all of us as writers — to be able to land on, explore, and explode new personalities, new voices, in each particular season, and to have such great success with so many of them.

The Mikaelsons of course led the way for “The Originals,” which was a pretty logical choice for a spinoff based on the characters’ rich mythology. The finale also set up a good path for something more too: Caroline might be “Originals” bound and we could probably watch Bonnie traveling the world, if it’s not too expensive for The CW. Were these opening for the possible continuation of “The Vampire Diaries” universe?

I think probably everybody involved with “The Vampire Diaries” needs a nice, long break from being a vampire or witch, werewolf, etc. And if, when they come out the other side of that hiatus, they want to show up in “The Originals”’ sandbox, they are all absolutely welcome with open arms.

We live in a world of reboots and continuations and crossovers. Would you be willing to do something like that even further along the line?

Absolutely. I think that if Dick Wolf can do it across nine shows, I think that maybe we could find our way through another “Vampire Diaries” universe.

Like “The Vampire Diaries: Chicago”?

Yes, exactly. You know, I’d love to see other countries take a stab at making their own version of the show. I think that would be fun to sit and watch the show produced from the beginning in a different language, with local talent, and really see how they interpret the story in different reasons. I think that would really be a blast.

Now for a very serious question: In the history of the series, who had the best hair? Stefan, Damon, or Alaric? Keep in mind that Elijah is a cheater’s answer.

You can’t beat “hero hair.” You can’t beat it. I mean, Damon had some good moments, but boy oh boy did he have some brutal moments. And Matt Davis was forever in pursuit of his Season 1 haircut, even as he got older, and it didn’t look so good. So he too made some specious choices at the salon over the years. But Stefan had the consistent hero hair, I have to give him props. And our hair team.

Is there any final message you’d like to relay to the fans?

Just a big thank you for growing up with us and for sticking with us and for loving us so much. And I hope that they [got] to have a positive emotional experience bringing it all home tonight.

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