The 100 creator Jason Rothenberg explains that explosive and emotional episode 

'The 100' composer reveals how he scored emotional scenes

episode “Thirteen,” which aired Thursday, Mar. 3. You’ve been warned — spoilers to follow.

“Thirteen” was billed as an origin story episode, but the audience didn’t know it would also contain huge character moments for Clarke and Lexa. After finally sleeping together — twice — the couple faced a tragic ending when Lexa died at the hand of her flamekeeper, Titus. And if that weren’t enough, we did get the promised origin story: We saw the world end and learned how the second AI ties into Grounder lore… and could maybe keep Lexa “alive”? (You can read the full recap here.)

Here, showrunner Jason Rothenberg helps us understand the shocking episode: He explains how the writers arrived at those major moments, what it will mean for the show, and where the rest of season 3 will go.

ENTERTAINMENT WEEKLY: The Arkers knew a little about Polaris — how much of what we saw in flashbacks did they know?

The fact that there was an AI involved, the fact that all of the things that we see play out in the flashbacks of episode 7, those things were not known to anybody, including Jaha. The circumstances around Polaris were not made public. In fact, the commander of Polaris, who was talking to whomever was in charge of the Alpha Station (the American station) never told them what was going on — so they didn’t even know.

We’ve heard about the 13th station a couple times throughout the series. Was it always your plan to do

I knew I wanted to tell that story, but I didn’t know how it was going to turn out until we started this season. It seemed to be a perfect way to tell the origin story of our show — which is we see how the world ended, we see how the Ark came together, we answer the question of the 13th station, but we’re also telling the story of the second AI, which is very, very important going forward in this season.

We never said anything about an AI before, so we needed to come up with a backstory that worked with what we’d seen before and showed it to us in a slightly different way. Ultimately that’s what we always want to do with flashbacks. If we’re going to tell a flashback story, it’s not going to present the information that we already know as we already know it; there’s always a twist to it. [These flashbacks don’t] exist just to fill in some blanks in people’s minds. It’s actually a crucial bit of storytelling so that you can understand where we’re going.

big thing that happened: Lexa’s death. How hard was it to make that decision?

I loved Lexa. I loved Lexa more than anybody else does. And she was an incredible character and

an incredible character, so I’m really sad that we’re not getting to write her anymore and tell her story anymore. [But] I felt like the story that we’re telling needed that moment because ultimately we’re telling the story in which reincarnation is possible — it’s a technological reincarnation, but it’s reincarnation. And to do that, to be reincarnated, first you need to die. And so that became the obvious endpoint for the story.

What was your thinking behind having Clarke and Lexa finally sleep together… right before Lexa dies?

Well … [pause] … that was a hard one. I knew that I wanted to have them have that moment; I knew that I wanted it to happen this season; I just didn’t want it to happen too soon. Any episode prior to now it would have been too soon in my mind.

Taking out for a second the fact that Lexa dies in the episode, these two women who have fallen in love are now about to be forced apart because of the politics on the Ground. The Grounder blockade and the kill order that’s going out on all Skaikru, who knows how long that’s going to last? It forces Clarke behind that line.

I jokingly talk about how it’s like the summer of your senior year in high school: You’re going off to college, and your girlfriend is going off to another college. You don’t know if it’s ever going to be the same again, so you have goodbye sex. It’s emotional, and it’s sad, and it’s lovely. That was what we were going for. In this case, it just so happened to be their first sexual encounter.

They didn’t know that it was the last, but they certainly knew that they were going to be apart because of politics on the Ground. And then the tragedy strikes, and that didn’t have anything to do with the fact that they had just made love.

She’s going to be heartbroken. She’s going to be devastated. It’s going to be something that haunts her forever, much the way Finn’s death does still, much the way what happened in Mount Weather does. She loved Lexa and was certainly falling in love with Lexa and will now be forced to figure out a way to go on.

One of the things that we do in this show: Death comes tragically and fast, the way it does in life oftentimes. When these horrible things happen to us, we all have to figure out a way to compartmentalize emotionally and to go on and continue being the heroes of our own lives. Clarke, the hero of

In large part she’s going to be driven by trying to fulfill the promise of Lexa, to make sure that Lexa’s life was not taken in vain and that her desire for peace is something that is followed through on. Some of that is probably going to revolve around whom the next commander is. These are stories that we’re going to tell going forward.

Should we be worried about Titus not honoring Lexa’s last wish to protect Clarke?

Sure, you can worry about that. Titus is ultimately going to go down as a villain for obvious reasons and probably

But to me, it’s heartbreaking what happened to him. He loved Lexa and was trying to — in his own twisted way — protect her and wound up killing her. That is the tragedy of a guy who kills his own child. (They’re not literally father and daughter, but he certainly considers himself that and knows how special she is/was.) And he’s now going to have to bear the responsibility of that. I think the greatest punishment of all for Titus will be the one he inflicts upon himself. He is going to be broken, certainly.

Hopefully the audience will realize we’re talking about an actress who’s starring in another show, so I really didn’t have a lot of options. … She was only was available to us for seven episodes this season — and beyond that, maybe never again available to us. So as a storyteller/showrunner, I needed to weigh that against the story that we’re telling. I happen to think it’s an amazing story that we’re telling, but certainly the decision to kill that character was made a little bit easier by the fact that I knew we weren’t going to get to play with Alycia Debnam-Carey anymore. Hopefully, people can forgive me. If they can’t, I understand that, too.

Well, we know now that the Ground is a place where people can live on in the City of Lights. With that being said, is this the last we’ve seen of Lexa?

much about that other than to say in addition to her living on in Clarke’s memory, we are talking about a world where you can upload your consciousness into a — we call it the flame — but into a piece of tech. Is Lexa in that piece of tech? Is Lexa in the flame? Is her mind in the flame? These are questions that we will ask and answer this season.

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