'The Society' Stars on Cassandra's Shocking Fate and the Violent Aftermath (Exclusive)

Rachel Keller and Seth Meriwether talk to ET about the biggest jaw-dropping moments from Netflix's latest teen series.

Warning: Spoiler alert! Do not proceed if you have not watched at least the first six episodes of Netflix's The Society. If you have, it is safe to continue...

Things were dramatic enough on The Society when a group of teenagers returned home to their small town only to discover their parents (and everyone else) had mysteriously disappeared. Questions quickly surfaced: Who would run the new society? What happened to the off-putting smell? Would their parents ever come back? But by the end of episode three, these would be the least of their problems. 

A modern-day take on Lord of the Flies, with elements of Gossip Girl-meets-Pretty Little Liars, Netflix's latest teen drama pulled the rug out from under everyone when Cassandra Pressman (Rachel Keller), who became the de facto leader of the group, was killed by two gunshots -- fired by someone she knew -- early in the 10-episode season.

"I knew [about it] and it made sense with the story," Keller told ET's Katie Krause of the unexpected twist at the end of the third hour.

The 26-year-old actress likened Cassandra's shocking, seemingly out-of-nowhere murder to a similar development that happened on AMC's The Terror. "They did a similar thing, where you're heading in one direction in the storyline and then you just go a completely different direction. I love that in storytelling," Keller explained. "I think it's really surprising and spontaneous for the audience, so hopefully we give it that flavor."

While Cassandra's death becomes the catalyst for violence and chaos amongst the group -- her younger sister Allie (Kathryn Newton) later takes over as leader -- Keller had a message for fans who may still be reeling over her character's untimely demise. 

"I'm sorry and I hope you keep watching, 'cause this is an incredible, incredible group of actors and storytelling!" she said.

Dewey (Seth Meriwether, left) is put on trial, with a faux lawyer in Helena (Gideon Adlon, right) for the shocking death of Cassandra (Rachel Keller). - Seacia Pavao/Netflix

After Cassandra's death, the main mission shifts to catching the culprit who fired the fatal gunshots. It's revealed soon after that Greg Dewey (Seth Meriwether), the unassuming town nerd, is Cassandra's murderer. After a pseudo trial, where he was found guilty by a jury of his peers (and later, a confession in a stunning 180), Allie made the difficult call to have him executed as punishment. An eye for an eye and all.

Meriwether shared that he wasn't aware until right before filming his big episodes that Dewey was the one behind Cassandra's murder. "I was talking to [creator] Chris Keyser about that a little bit. Going into the show, I didn't know. And I didn't find out until right before it happened," he revealed to ET. "Anything you see, reaction-wise, I was kind of in the dark. I thought that was really smart of him."

Meriwether admitted that when he did read the script IDing Dewey as the killer, he was understandably stunned.

"I found that out and I was like, 'Oh crap.' This changes -- this gives a lot of other characters a lot of dynamic moves now as to how they react to things like this. [It] is a very pivotal thing in our society today, if you look at the politics of capital punishment, death penalty versus non-death penalty," he said. "For me, to do that, I had to really change my thought process of why would this guy do this? Where is he at in his head where [something] has made him go and do something [like this] to the highest degree?"

"[It's] the most heinous thing you can think of," Meriwether added. "It was kind of weird getting to that spot and having to try and get into my own mind. 'OK, what kind of home life did this guy have? Is he just trying to fit in with the guys and it's not a big deal to him? Maybe that's the way he thought of it?'" 

When asked about the society's controversial "eye for an eye" mandate, which resulted in Dewey's cold-blooded execution, Meriwether said how the audience responds to that piece of the story will be interesting to follow.

"It depends on how you view things in your own life," he said. "I think there will definitely be some people that are upset about it, maybe because we are kids, but at the same time, if I were watching, I'd be like, 'Oh yeah, he had it comin'.' It's a tough one, 'cause you're not talking about something that doesn't have consequences. It's someone's life, but it's both sides of the coin. It gives it a lot of tension."

As for whether Cassandra could return to the fold, whether it be through flashbacks or even a resurrection of some sort (you can't count anything out!), Keller was coy.

"That would be a Chris Keyser question," she hinted. "Girl, I don't know what I'm doing tomorrow!"

The Society is now streaming on Netflix.

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