Hannah Waddingham describes enduring 10 hours of waterboarding for Septa Unella's 'Game of Thrones' death

Game of Thrones built its empire upon fictional brutality, and Septa Unella's demise fit firmly under that umbrella in the Season 6 finale.

However, according to Hannah Waddingham, her character was originally meant to suffer much worse and she actually did endure hell while filming the fateful "The Winds of Winter" scene.

"She was meant to be raped by The Mountain (Hafþór Júlíus Björnsson)," Waddingham revealed on Collider's "Ladies Night" with Perri Neminoff, "and I think they'd had so many complaints about the rape of Sansa (Sophie Turner) that they chose not to go with it."

Waddingham continued: 

"But, unbelievably, they changed it quite at the last minute. I think they possibly changed it when I was midair flying to Belfast because, suddenly, I got sent this new sides that said that I would need a wetsuit top. I thought they had sent me the wrong bits. And sure enough, when I got there, I was then put in a wetsuit top. And I was like, 'Because?' And they went, 'Oh, it's waterboarding instead.' And I was like, 'Oh, but we're not actually doing waterboarding?' 'No, no, no, we are.'  And there I was, strapped to a wooden table with proper big straps for 10 hours, and definitely other than childbirth, it was the worst day of my life. Because Lena (Headey) was uncomfortable pouring liquid in my face for that long, and I was beside myself. But in those moments, you have to think, do you serve the piece and get on with it? Or do you chicken out and go, no, this isn't what I signed up for?"

Waddingham's eight-episode arc as Unella concluded with Cersei Lannister (Headey) imprisoning and torturing her, pouring wine on her face in an attempt to get Unella to confess. The last viewers saw of Unella was her getting locked away with The Mountain indefinitely. (Earlier in the series, Unella had imprisoned and tortured Cersei for a confession.)

Game of Thrones ran for eight seasons from 2011-19 on HBO.

Luckily for Waddingham—and the rest of us—she has transitioned into lighter fare as Rebecca Welton in Apple TV Plus series Ted Lasso, which stars Jason Sudeikis as the titular character. Welton hires Lasso, a Kansan with American football coaching experience, as the new manager for her ex-husband's English soccer team.

Watch Waddingham's full segment—where she also discusses the "claustrophobia around water" she struggled with as a result of filming as well as positive lessons she took away from the traumatic experience—and the Season 2 Ted Lasso trailer below.