It’s the end of the world as we know it on The 100.

In just one game-changing scene in the season three finale, The CW’s post-apocalyptic series transformed into a pre-apocalyptic one, as Clarke (Eliza Taylor) learned from artificial intelligence ALIE (Erica Cerra) that the world’s remaining nuclear power plants were melting down, and in just six months the planet would once again become uninhabitable for humans. That didn’t stop Clarke from shutting the City of Light, giving everyone their free will back, but it also destroyed their only “salvation” from impending doom as they could now once again feel pain and death.

While previous seasons featured time jumps in between finales and premieres, season four wastes no time and hits the ground running in “Echoes.”

“We pick up right where we left off,” creator/executive producer Jason Rothenberg told Nerdist. “Unlike the time gap between season two and season three, which was three months and we really presented an entirely new Arkadia, this season picks up seconds later really, so there isn’t a whole lot different. We will eventually un-peel the onion even further and show more of the world and there are new sets and crazy new characters and it’s a totally new story. But in terms of having an audience need to catch up, they don’t – it’s a direct pick up from season three.”

Season four will feel like a new chapter for the show, as it is the first time that the Skaikru faces an obstacle they can’t physically fight. The world-ending radiation, known as the “death wave,” can’t be stopped.

“It’s apocalypse part deux,” Rothenberg said. “It’s post-apocalyptic and apocalyptic at the same time. We get to see these people dealing with the fact that there’s no surviving what’s coming at them. That’s really revealing of character and allows for some unique situations that we haven’t seen before on the show for sure. Across the board, this death wave ironically has infused a new life into the show and certainly into all of the characters’ journeys.”

Because the end of the world will have such a different impact on each of the fan-favorite characters, Nerdist visited The 100 set in Vancouver to find out just where their journeys will take them in season four. Check out what the cast and creator had to say about all your favorites below!

Clarke

As the only person who knows the impending doom that is coming for everyone, Clarke will shoulder more responsibility this season than she ever has before.

“Clarke is always at the center of everything,” Rothenberg said. “Her journey is incredible from needing to realize that she can no longer just save her own people to transcend all of that tribalism and become somebody who is only going to be satisfied if she can save everybody, even if that means for the first time perhaps giving up something of her own people or for her own people in order to get that.”

But at the start of season four, Clarke isn’t sure if she should even reveal the horrible truth to everyone on Skaikru and in the Grounder coalition.

“It’s something that she has to be really careful about because obviously she’s just taken all these people out of a beautiful city that they were happy [in] and brought them back into a world that’s about to end,” Taylor said. “So she has to be very careful about how she goes about telling people without starting a riot, basically.”

At least the “lone wolf” will finally realize that working alone won’t cut it, not when the fate of every person on Earth is on the line.

“You will see more of her relying on her friends and family, which is good because it’s kind of like the old crew being back together again,” Taylor said. “It feels like season one again, which is awesome. She’s definitely stepping up more and accepting herself as the leader, which is really great. It’s really fun to feel like she’s asserting herself and not taking any [s-t] from people who don’t know as much as she does exactly what’s going on.”

In the midst of figuring out how she can save everyone from another apocalypse, Clarke is also still dealing with her broken heart. Remember, it hasn’t been that long since her love Lexa (Alycia Debnam-Carey) was tragically shot and died in her arms. When season four picks up, Clarke still has possession of Lexa’s Commander Flame, but not for any political reasons.

“For Clarke, the Flame is still so important to her because she still believes that it’s Lexa,” Taylor said. “She’s holding on to it as a keepsake. There’s just so much else going on that she doesn’t really have time for relationships right now. She’s grieving for Lexa but at the same time she’s open to moving on, I guess. I don’t know. I really want her to get it on with someone. I think it would be great. But they don’t tell me if that’s happening.”

As for her friendship with Bellamy (Bob Morley), the two former co-leaders will work together once more to save their people.

“They’re on the same team again, which is really cool and you saw that at the end of season three,” Taylor said. “They’re a real team and I really like the way their storyline is going. There’s a lot of mutual respect and they’re sharing the leadership role, so that’s cool.”

Bellamy

No one can deny that Bellamy has made more than his fair share of mistakes ever since he came down from the Ark. But the person who is judging Bellamy the most is Bellamy himself, especially going into season four.

“Bellamy is trying to right the wrongs from his past and do the most good that he can before the end,” Rothenberg said.

Morley added, “All the decisions he’s made since season one always hang over his head. So it’s just another addition to the amount of guilt and remorse that he has. He’s got a lot of weight on his shoulders and he’s carrying that around but has to find a way to be useful again and to be helpful to those around him that he loves. It’s going to be dealt with, we’re constantly dealing with that stuff. The culling of the 500, Mount Weather, it doesn’t just go away. That’s the great thing about this show, I get to carry around those demons forever. That’s definitely prevalent this season.”

One of the ways in which Bellamy will fight his own demons on his path towards redemption is helping calm down the chaos that Polis will find itself in after everyone comes to from their City of Light chip dream.

“Not everyone knows about the six months impending doom – only me and Clarke – and that’s the biggest threat in the forefront,” Morley said. “Obviously there are still a lot of questions to be answered in Polis and everyone is coming down off the chip high, so there’s the fallout from that that people have to deal with. There’s a whole bunch of people who turned up to Polis under the guidance of ALIE so once everyone’s out of it, there’s a whole bunch of clans and people brought together by this and have to deal with what they’ve gone through and the fallout from that. Also, not all clans get along so there’s that immediate place of waking up and being like, ‘There’s a whole bunch of people here that I don’t know or get along with.’ How do you confront that situation?”

One relationship Morley was excited to explore in season four was that between Kane (Henry Ian Cusick) and Bellamy, as they started off the series back in season one as mortal enemies.

“You’ll see a lot of Bellamy and Kane’s relationship which is really great for me. I love working with Ian. We have a lot of fun,” Morley said. “He’s like, I guess, adopted me as his son or vice versa, maybe I’m the father figure between the two of us. There’s a lot of that stuff, Kane and Bellamy. And obviously the relationship with Octavia [Marie Avgeropoulos] is always something that has to be addressed and we address constantly that ever-evolving relationship. Clarke and Bellamy will always have their differences but try and work together. There’s a return of the adventure squad of the younger kids as well which is a lot of fun. This season I’ve got to spread myself around a lot and work with a lot of different people which is nice.”

When it comes to the impending apocalypse, Morley explained that everyone will make a choice in how they react to the news.

“Whether you decide to find a way to get through it or find solutions to live through it or whether you start making a bucket list and just decide to let it wash over you in a literal sense, there’s that existential dilemma of whether we deserve to survive or whether should we live the rest of our lives hedonistically with whatever we have left,” Morley said. “That’s definitely the clock that is ticking throughout the season.”

Where does Bellamy fall on that spectrum? “It changes every day,” Morley said. “He’s a very interesting character this season. He always has been very complex. Sometimes the writers like to put me in positions where I don’t necessarily agree or I agree wholeheartedly and that’s the beauty of it. He kind of is a metronome in that sense where he’s back and forth so I don’t think there is a real straightforward answer to that. It’s nice for me to play but it’s also very challenging. Like most people he changes his mind and that’s okay. I don’t think there is any one way that he leans. We’ll have to wait and see. I’m still finding out myself.”

And that makes it especially interesting to note that Bellamy and human cockroach Murphy (Richard Harmon) will actually strengthen their alliance this season.

“I’m not sure what I can tell you about what the dynamic is going forward, but I can tell at the beginning of season four the dynamic between the two of them is probably the best it’s been since the beginning of the show,” Harmon said. “Maybe not that they like each other, but I think a little bit of respect definitely has blossomed between the two of them. As a character on the show I think you have to respect any of the other characters that are still alive because you know they’ve been through something. They’re still breathing and I think as a character you just have to give them that respect. Me and Bellamy came back together, saw each other, had to work together and just went like, ‘Hey man, good for you, still breathing. That’s pretty cool.'”

Octavia

All hail the “Sky Ripper, death from above.” Bellamy’s little sister will continue her descent into darkness this season after losing the love of her life Lincoln (Ricky Whittle) and murdering the former leader of Skaikru in front of everyone.

“Octavia’s journey is incredible this season,” Rothenberg said. “It’s dark and twisted and takes turns that we won’t see coming but will ultimately feel like it was totally natural towards the end.”

But just because Octavia has become a killing machine, that doesn’t make her a villain. While her murder of Pike (Mike Beach) was cold and ruthless, in her mind it was justice for him killing Lincoln just because he was a Grounder.

“Everyone sort of knew, based on the Romeo and Juliet romance that was Lincoln and Octavia, how significant that romance was to her,” Avgeropoulos said. “They just kept making such immense sacrifices for one another, and fighting for their love, so once Pike executed Lincoln and she was there to watch the whole thing, I think everybody knew that would have a massive impact on her. The revenge and justice was coming in due time.”

Killing Pike won’t heal Octavia’s broken heart, however.

“Octavia’s never received any love from any man before other than Bellamy, so to have such a love like that enter her life and then leave so horrifically, it affected her in a really negative way,” Avgeropoulos said. “The only thing I can really relate it to is like when people use substance abuse or alcohol abuse to deal with things that affected them in bad ways to numb that pain. Octavia does that by executing people and killing them and using that as an out to not feel things. That’s her next drink, that’s her next drug, so when she does snap out of that it’s a pretty awakening moment for Octavia, and allows for some real soul searching and almost grieving again for a second time.”

She continued, “Her mind is so clouded with the devastation of Lincoln and a lot of points in this season, you can just see her not thinking straight. She’s a very stubborn girl too and just thinks her opinion in that moment is always the right one, when that’s not always the case.”

Will she ever learn to love again? “Octavia has a pretty significant interaction with one of the male counterparts in a different tribe this season,” Avgeropoulos teased. “I can’t tell you more than that, to give it away. No one will ever replace Lincoln. Let’s just face it. Don’t freak out. And I can’t tell you if it’s in a positive or negative way, but you do see Octavia and Roan [Zach McGowan] come together and form an alliance that maybe even becomes broken at one point too, so you can see both sides of the story. You’ll have to tune in.”

When it comes to Octavia’s friends, they haven’t given up on her despite her going down a dark path.

“Octavia has kind of decided that she doesn’t belong to Arkadia and she doesn’t belong to the Grounders,” Taylor said. “She’s kind of become this lone wolf, similar to the way that Clarke did at the beginning of season three. And I think that there’s a very good mutual understanding there with not feeling like you belong and wanting to just kind of disappear and live your own life. With that in mind, while they don’t particularly see eye-to-eye on a lot of things, I think there is a very subtle mutual respect. They listen to each other, even if they disagree. You’ll definitely see more of that.”

While it will cause Bellamy pain to see his sister push everyone away, he won’t give up on her either.

“That relationship with Octavia is one that I would really like to see develop into a more adult type relationship as opposed to him berating her and her telling him, ‘You can’t tell me what to do.’ That whole back-and-forth dynamic,” Morley said. “With her taking this darker turn and it being much more of an emotional turn and an outward expression of that, it’s something that Bellamy has experienced before as well, so there’s a level of understanding there. He expresses that but there’s also a level of loss. I don’t think he necessarily wanted that for her. He said that at the end of season three when they’re barricading the door, ‘I know what it’s like and I just don’t want this for you.’ And then she makes the choice to kill Pike in the end.”

He continued, “That’s an indicator to him that she doesn’t really need his advice or listen to his advice anymore. It’s a bit of a blow for him. At some point you do have to take a backseat with the people you care about – you can’t give them the answer, they have to find it themselves. It’s one of those journeys that will take some time. Lots of healing and water under the bridge. It takes its toll.”

Murphy

Everyone’s favorite hated survivor Murphy hasn’t died yet, and he intends to keep his streak going in season four.

“We’re going to start off right where we left off. Everything has just gone to crap,” Harmon said. “City of Light has been taken down, which I think is a good thing for us, but also we now know the impending disaster that’s coming our way. I think we’ll start right there and slowly but surely I think all of the characters are going to start to figure out what’s going on and why this might not be a day to celebrate.”

According to Harmon, “a big theme of this season is seeing everyone’s true colors when all the chips are on the table.”

“This is coming. It doesn’t really look like there’s any way we’re going to be able to get around it,” he said. “It’s probably going to kill us all. What do your favorite characters do with that information? Do some of them actually try to fight against it with almost no hope of survival or do you give up and just enjoy your last couple weeks or months or however long it is on Earth? Speaking for Murphy specifically I think we’ve seen him be a survivor this entire time. There’s been pretty bad times for him and times when he’s had nothing really to live for and he’s survived anyway just because he doesn’t want to die. That’s not going to change anytime soon. The guy cares, especially now that he has something to live for in Emori [Luisa D’Oliveira]. I think he’s trying to get along with the group a little bit better. I think he’s, now more than ever, finding his place within the 100 team.”

While Murphy always put himself as his first priority, finding love in Emori will slowly change him, making him a better person against all odds. But that doesn’t mean their relationship will be smooth sailing.

“We’re going to see a relationship that is strained through the adversity of knowing the world is coming to an end,” Harmon said. “I think that’s a hell of thing to put any relationship through, but I know those two really care about each other. They’re two outsiders that have finally become insiders through each other. It’s a really beautiful thing and I’m really excited for fans to see where we’re going with that.”

And be prepared for some Murphy-centric episodes this season. “Episode 6 is probably my favorite that we’ve done so far for Murphy,” Harmon said. “It’s really great. It really kind of gets into a little bit of who he is more as a person. It’s a great character episode. Also, episode 8 that we just shot is really great. I’m not going to tell you why, just mark down the calendar for whenever those are if you like Murphy.”

Jasper and Jaha

Two characters who will find themselves in completely opposite places as they were last season are Jasper (Devon Bostick) and Jaha (Isaiah Washington). Jasper spent most of season three depressed and in pain, but when he learns of the impending death wave, his entire outlook on life (and death) flip-flops.

“Jasper is done fighting and knows that the end is coming in six months,” Rothenberg said. “He’s just going to kick back until the end and hope to enjoy himself as much as possible.”

Much of the comic relief will come back to the show via Jasper and his BFF Monty (Christopher Larkin), but former Chancellor Jaha will find himself paying for all his mistakes of helping ALIE bring the City of Light to the Skaikru and Grounders.

“Jaha is dealing with the ramifications of bringing forth the City of Light and the constant consequences of his sins,” Rothenberg said. “And yet he is still focused almost relentlessly, single-mindedly on saving his people.”

Want to talk all things The 100? Tweet me at @SydneyBucksbaum!

Images: The CW

The 100 airs Wednesdays at 9 p.m. on The CW.