'Game of Thrones' Star Weighs in on Last Night's Shocking Episode

-- SPOILER ALERT AHEAD

If you haven't seen Sunday's "Game of Thrones," be warned!

On last night's "The Mountain and the Viper," Pedro Pascal, who plays Prince Oberyn, had the character The Mountain defeated but wanted a confession, so he made the age-old error of not striking but talking, eventually resulting in his demise.

And what a violent demise it was, with his head basically exploding at the hands of The Mountain.

Pascal talked to Vulture about that fatal, final scene.

"People love the brutal honesty of the show, that is uncompromising," he said. "I got all 10 episodes of the season before I flew out to Europe, and I read them voraciously. I'm a fan of the show, and I was reading them like a regular fan at first, you know? And I read all the episodes back to back, really, really quickly. And when I got to my final episode, I was really impressed by how similar it was to the scene in the books."

Read: 'Game of Thrones' Creator George R.R. Martin Reacts to Shocking Episode

Related: 'Game of Thrones' Director Opens Up About Controversial Sex Scene

Pascal added that when he started rehearsing with The Mountain (Julus Bjornsson), who is just about 400 pounds, Bjornsson had just come back from proving he actually could crush a man's head with his bare hands.

"Hafor [Bjornsson] was competing in a strongman competition in China, and he came back with the title of third strongest man in the world!" Pascal said. "That's pretty impressive. Our stunt coordinator told me, 'Just so you know, he's the third strongest man in the world. It's official.'

"And so we really had to jump into rehearsal immediately," Pascal added. "I've never done anything like that before, as far as my work is concerned. I've done typical combat classes, and there have been roles that were very physical on stage or on screen -- I played a boxer once, and I fought Maggie Q on an episode of 'Nikita' -- but nothing like this."

Aside from his imposing size and what his character does on the show, Pascal said The Mountain is a "gentle giant" in real life.

"We had a lot of fun," he said. "It was still really, really challenging, and I was totally intimidating, and I wanted to get it right -- for the readers, for the production, and for me. And everything lined up in my favor. Stepping into it was a really scary thing, but the doing of it was the most fun I ever had. It was nuts! With hundreds of extras watching, a lot of the main characters watching. It was big."

Pascal told EW that his last day on set was "lovely and peaceful."

"It was the scene strolling through the garden with Lena Heady and the last thing they shot was when I was looking out into at Adriatic Sea. Then I tore off my costume and jumped into the ocean. Then I said goodbye to everybody and got in the van and rode to the airport."

As for what his character did wrong that led to his demise.

"Getting too close and being too far delivered by his own passions," he told EW. "Because ultimately, it is about defeating this man who raped and killed his sister, but before he can do that, before he can end this man's life, he needs a confession. He needs to hear it. And interestingly, I had this great conversation with Lena Headey about Oberyn's journey, and how even though it ends badly, he still hears the confession, you know? I don't even need to go on after that once it's been said out loud."