Sundance: Kristen Stewart on 'Camp X-Ray's' Haunted Set, Meeting Robert Redford (Video)

"I shook his hand and he was, like, 'Are you nervous?' and I was, like, 'Yeah, I'm shitting my pants,'" the "Twilight" actress said of meeting the Fest founder.

PARK CITY, Utah -- After the premiere of Camp X-Ray on Friday, director Peter Sattler and the cast -- Kristen Stewart, Payman Maadi and Lane Garrison -- stopped by THR's video lounge to talk about the drama about a Guantanamo Bay prison guard.

Twilight star Stewart plays the young guard, who strikes up a friendship with one of the prisoners (Maadi).

The cast spoke to THR about shooting the film at a prison in Whittier, Calif., where Guantanamo was recreated.

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"There's a lot of reference material, so we came to know these hallways through these documentaries, so the first time I walked onto the finished set, it was like you walked into the documentary," she said. "And it's haunted."

The cast agreed with Stewart that the Whittier prison had a strange vibe. "Walls have memories," she added.

Stewart, who has also been to Sundance with several other films over the years, shared an interesting story about meeting founder Robert Redford at the fest.

"He was, like, 'How you doing?' And I shook his hand, and he was, like, 'Are you nervous?' and I was, like, 'Yeah, I'm shitting my pants,' and he was, like, 'Good, it would be weird if you weren't,'" she said.

Watch THR's complete interview with the cast of Camp X-Ray above.

Twitter: @Beccamford