‘The 100’ Stars Talk Nuclear Threat In Season 4

Earth faces its
greatest threat when “The 100” returns for its Season 4 premiere on
Wednesday night.

As ALIE warned at the
end of Season 3, nuclear annihilation is on the way unless Clarke and the gang
can find some way of stopping it.

“This
whole season’s mostly based around kind of how we’re going to deal with fighting an
enemy that we can’t go to war with,” Eliza said in response to a question from AccessHollywood.com, on a visit to the
show’s set with reporters in Vancouver last fall. “So it’s going to prove very
interesting.”

WATCH: Eliza Taylor: ‘The 100’ S4 Is About ‘Fighting An Enemy That We Can’t Go To War With’

Bob Morley, who plays Bellamy, said the secret weighs heavily on those who know the truth.

“[Not] everyone knows about the impending doom, the six months … Bellamy and Clarke have that, but that’s the biggest kind of threat in the forefront,” he told reporters on the same set visit. “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. But yeah, it’s a pretty straightforward continuation of the story from last season.”

WATCH: Bob Morley On Biggest Threat In ‘The 100’ Season 4

Clarke will have to make tough decisions about who she lets in on the secret as the season rolls out.

“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 where they were happy, and brought them back into a world that’s about to end,” she said. “So she has to be very careful about how she goes about telling people without starting a riot, basically.”

The impending apocalypse will affect those who learn about it in different ways, Bob said.

“It’s a huge factor throughout this season. It’s this impending doom that we all have to figure out how to address that and whether you decide to find a way to get through it or find solutions to live through it or whether, yeah, you kind of start making a bucket list and just kind of decide to let it wash over you, I guess, in a literal sense. So… there’s that existential dilemma of whether we deserve to survive or whether we should we live the rest of our lives hedonistically with whatever we have left,” he said. “That’s definitely the clock that is ticking throughout the season.”

WATCH: Zach McGowan Teases What Roan Will Be Dealing With In ‘The 100’ Season 4

But could the need to tackle this problem create new alliances?

“I think this show loves to pair groups of characters together that you wouldn’t necessarily expect,” Bob said. “So, ticking clock or not you always see these couplings and these groups that go out that you wouldn’t necessarily imagine being friendly or aggressive or whatever it is … [T]he ticking clock obviously is one of the catalysts to putting these groups together. But, yeah, there’s a whole heap of different groups that you don’t usually see and that’s what I think the writing team really likes to explore is putting characters together that you wouldn’t expect together.”

The nuclear threat is one of many facing the characters of “The 100” this season. There will also be continuing storylines for the characters who were chipped last season.

“Yeah, you definitely get to see the fallout side of the story of that and how that affects everyone,” Bob said. “It affects everyone in completely different ways and those people that weren’t on the chip as well.”

“The 100” returns Wednesday at 9/8c after “Arrow.”

(Production assistance provided by Warner Bros.)

— Jolie Lash