'The Traitors' Host Alan Cumming and Contestants Brandi Glanville, Kyle Cooke, Rachel Reilly and Arie Luyendyk Jr. Dish on Deceptive New Peacock Series (Exclusive)

Some of reality TV's biggest names are coming together to compete against civilians – and one another – in a deceptive and dangerous new competition series for Peacock. The Traitors, based on the hit Dutch series of the same name, throws some of the biggest stars of reality television into the deep end of a psychological adventure based in a castle in the picturesque Scottish Highlands. 

Ahead of The Traitors' premiere on Peacock on Thursday, Jan. 12 competitors Brandi Glanville (Real Housewives of Beverly Hills), Kyle Cooke (Summer House), Arie Luyendyk Jr. (The Bachelor), and Rachel Reilly (Big Brother) opened up to PopCulture.com about what it took to compete in the nail-biting challenges, while host Alan Cumming teased the action to come when no one knows who are the "Traitors" hidden among the "Faithful."

"I was a little bit of a fish out of water," admitted Cooke, who not only has never competed on reality TV but also has "never really watched" any competition shows for reference. "I went in knowing nothing and I mean, you might think that might be advantageous because you kind of come in a clean slate ... but I definitely have my back up against the wall as opposed to swinging from the chandelier on Summer House."

Even a seasoned competitor like Reilly, who has made her name as a serious threat on shows ranging from Big Brother and The Amazing Race to Celebrity Fear Factor, admitted The Traitors was like nothing she had ever seen before. "I think going into the game, I was a little overconfident because once I got there I literally had no idea what to expect. I literally went in – I was like, 'I know this is going to be a piece of cake. I'm going to win this,'" she told PopCulture. "And then I was like, 'Oh my gosh, there are Traitors, there's Faithfuls, there's banishments and murders and treachery and backstabbing.' ... It's really hard to navigate that."

"Preconceived ideas" also put the celebrity competitors at a possible disadvantage when it came to playing against civilians. "With me, I think that people, they see highlights of my bad behavior and they assume that's me at all times," Glanville told PopCulture. "And I am outgoing. I love to joke. I'm always joking because I just feel like, why not? This is who I am. But I have a serious side. So I did feel the need to perform a little bit for the people that didn't know me, to give them what they wanted. But at the same time, I was constantly thinking and constantly going, 'OK, this person's not my friend. ...It was a mind F."

Luyendyk Jr. agreed: "I think you have to be careful because every little thing that you do is being watched, and so the kind of the person that you arrive to the castle as – you really have to stay consistent. So if you are outgoing and outspoken, you have to continue to be that way. Or if you're more reserved and observant, then I think then if you start changing or start getting more comfortable, then it's like, 'What's up with him?' or, 'What's up with her?'"

As the host, Cumming admitted it was "kind of horrifying" to have the power of being the only person to know the Traitors from the Faithful, but that watching the dynamic shift between the celebrities and civilians was thrilling. "It was really fascinating because it's a very leveling thing when you're in a situation like that, I imagine," Cumming told PopCulture, noting that it's "really interesting when it gets down to towards the end about the sort of ratio of real people to celebrities." The actor teased, "The real people, they do pretty well, I'll say that."

Also competing on The Traitors are Cirie Fields (Survivor), Cody Calafiore (Big Brother), Kate Chastain (Below Deck), Reza Farahan (Shahs of Sunset), Ryan Lochte (Olympian), and Stephenie LaGrossa Kendrick (Survivor). The Traitors premieres with all 10 episodes dropping on Peacock on Thursday, Jan. 12.