British actress Hannah Waddingham has revealed that she was left with “chronic claustrophobia” after filming a scene where she was “waterboarded for 10 hours” for a scene in the famous Game of Thrones.

“‘Thrones’ gave me something I wasn’t expecting from it, which was chronic claustrophobia,” she said during her appearance on The Late Show With Stephen Colbert. “It was horrific. Ten hours of being actually waterboarded. Like actually. I’m strapped to a table with all these leather straps. I couldn’t lift up my head because I said that would be too obvious that it’s loose.”

Waddingham starred in the HBO series as Unella, one of the Septa of the Faith of the Seven, who brutally tortures Cersei Lannister (Lena Headey). But the tables turned when Cersei regained her power as she imprisoned and punished Unella.

Colbert had asked her about stunts. To this, the actress replied in negative and added that the series gave her something that she wasn’t expecting. Waddingham did praise the cinematography of the series based on a book of the same title.

“I’m on my way back [from set] with grape juice all in my hair so it went purple, I couldn’t speak because the Mountain had his hand over my mouth while I was screaming and I had strap marks everywhere like I had been attacked,” she continued. “One of the other guys who had been shooting something else was like, ‘You’re lucky, I’ve just been crawling through s*** on my elbow for four days.’ It kind of doesn’t matter when you’re in ‘Thrones.’ You just want to give the best.”

She first spoke about the waterboarded scene during a 2021 interview with Collider. The actor said at the time that filming the scene was second only to childbirth as the worst day of her life.