[Editor's note: The following contains spoilers through the Season 6 finale of Game of Thrones, "The Winds of Winter."]

You want to see an actor with great range? Compare Hannah Waddingham’s work in Ted Lasso to what she did in Game of Thrones. Yes, Rebecca is up to some no good in Ted Lasso, but ultimately she’s a good person making misguided choices due to pain and grief. Unella on the other hand? I’m willing to bet that just one word will cause everything she did over the course of her Game of Thrones run to come flooding back - “Shame!”

Unella is a Septa of the Faith of the Seven under the High Sparrow (Jonathan Pryce). When Cersei Lannister (Lena Headey) is arrested by the High Sparrow, it’s Unella who tortures her in her cell underneath the Great Sept of Baelor. Eventually, Cersei confesses and completes a walk of atonement back to the Red Keep with Unella yelling “shame” every step of the way. While that could have been the end of it, after six seasons of Game of Thrones, it came as no surprise when Cersei became determined to make Unella pay for what she did.

Hannah Waddingham and Lena Headey in Game of Thrones
Image via HBO

At the end of Season 6, Cersei has Unella imprisoned and tortured. The last we see of Unella, Cersei pours wine on her and demands that she confess, after which she’s locked in the room with The Mountain (Hafþór Júlíus Björnsson). It’s a brutal moment and impossible to shake, even after that door closes and the show moves on. However, Headey once mentioned that scene was meant to be worse.

What could be worse than what we saw in the finished product? While on Collider Ladies Night, Waddingham revealed the original plan:

“She was meant to be raped by The Mountain, and I think they’d had so many complaints about the rape of Sansa that they chose not to go with it.”

Lena Headey and Hafþór Júlíus Björnsson in Game of Thrones
Image via HBO

So that original story idea changed, and it changed rather last minute. Waddingham continued:

“I think they possibly changed it when I was mid-air flying to Belfast because suddenly I got sent these new sides that said that I would need a wetsuit top. And I thought they’d 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.’”

While one might assume that’d mean a form of movie magic waterboarding, that actually wasn’t the case. When Waddingham questioned the team about truly waterboarding her for the scene, the reply was, “No, no, no. We are.” Here’s how Waddingham described the filming experience:

“And there I was strapped to a wooden table with proper big straps for ten hours. And definitely, other than childbirth, it was the worst day of my life. Because Lena 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, blah, blah, blah?’ And then, the funny thing was, after we’d finished shooting it for the whole day, and people like Miguel Sapochnik, the director by the way, walking past with a cup of tea and a sandwich on-the-go and going, ‘Hi hunny, you alright?’ And I was like, ‘Not really.’ ‘The crew have just been saying we are actually really waterboarding you here.’ And I was like, ‘Yup, you don’t need to tell me that!’”

Eugene Simon in Game of Thrones
Image via HBO

Later on that night, Waddingham bumped into another Game of Thrones actor who had been put through the wringer, Eugene Simon who played Lancel Lannister.

“When I got back to the hotel that night, I was going up in the left and I was standing next to Eugene who had had to crawl through loads of sh*t to get out of the Sept of Baylor and he was like, ‘Oh my god, what happened to you today?’ I could barely speak because I had been screaming through The Mountain’s hand, which is quite frightening as a singer to completely lose your voice, so I had no voice at all to barely whisper, bruises already coming up like I had been attacked and I was like, ‘I’ve basically just been waterboarded for ten hours.’ And he went, ‘Mate, I’ve just been crawling through sh*t for four days on my elbows.’ So we were like, ‘See? You haven’t been in Game of Thrones unless you’ve been really, really, battered around.’”

RELATED:Why the ‘Game of Thrones’ Pilot Is So Much Better After You’ve Finished the Series

Hannah Waddingham in Game of Thrones
Image via HBO

Waddingham did have a laugh while looking back on her conversation with Simon, but there were also some rather serious lasting effects of filming that final scene. Here’s how she described it:

“I hadn’t even realized that it definitely gave me claustrophobia around water. Definitely. I hadn’t realized until I watched a program where the camera’s down on the actor’s face and they’re being dipped into the water, but you see them face-up to the camera, and I got in a terrible panic about it. And I actually went and had a bit of a chat to somebody about it, because it’s quite full-on being waterboarded for ten hours, and then only one minute and 30 seconds can be used on camera.”

Lena Headey and Hannah Waddingham in Game of Thrones
Image via HBO

Is a process like this an absolute must for a scene like Unella's final moment inGame of Thrones?How do you get thenecessary authenticity on screen without the lasting trauma off camera? Here's what Waddingham said:

“As a singer, the one thing that I was really worried about, I didn’t want the strap tight around my neck, but as they pointed out, if the camera can see you lifting your head up to save yourself, that’s not authentic. And it was Dan Weiss that came up to me and went, ‘Look, in the script it says Cersei empties the remainder of her glass of red wine to wake up Unella. People aren’t gonna think that’s enough. What you’ve put her character through, that is not enough retribution for Cersei, especially the kind of person that she is. It needs to be more like a three quarter full [glass], also if we can cheat it even more carafe of wine.’ And that’s what I mean about that moment of fight or flight. I just thought, ‘Do you know what?’ The one thing I kept thinking to myself, ‘The production company aren’t going to let you die, so get on with it, be uncomfortable.’ Like you were saying in your question, I would say, get on with it. As long as you feel like there’s not any genuine threat of something happening, push yourself, be uncomfortable. It’s the same as if people don’t cry on camera, don’t impart this emotion to the right moment. Why not? My whole thing has always been, take people to the absolute nth degree of their emotions and that’s the same thing. Give of yourself and then it gives back to you.”

For more from Waddingham on Game of Thrones, 2012’s Les Misérables, the incomparable Ted Lasso and more, stay tuned because we’ll have Waddingham’s full Collider Ladies Night interview for you soon!

KEEP READING:10 'Game of Thrones' Games That Best Adapted George R.R. Martin's 'A Song of Ice and Fire'