Kit Harington Jokes His Face Looks 'Weird' as Extrapolations Character Who Ages 30 Years: 'Be Warned'

JC Olivera/GA/Getty; Apple TV+

Kit Harington is aware of how shocking he may look in the finale of his new show Extrapolations.

At the series premiere at the Hammer Museum in Los Angeles on Tuesday, the Game of Thrones alum revealed to PEOPLE that he wore prosthetics in the last episode since his character ages 30 years in the Apple TV+ series.

"Because I'm meant to be 60 or 70 years old [by the end], I was like, 'There's two ways about doing this. You can either put the age makeup on, or he's a billionaire who has at his disposal the ability to look young and has tried to avoid aging,' " he told PEOPLE, adding that "it went down that route" to wearing "prosthetics."

Harington, 36, shared with PEOPLE that he thought his "face looks f---ing weird" in the series finale. "Be warned," he teased.

Apple TV+

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Written, directed and produced by Contagion's Scott Z. Burns, Extrapolations will tell eight interwoven stories of families and friends who are navigating a dystopian future in which the world is collapsing under climate change and global warming.

On why he wanted to be apart of the Apple TV+ series, Harington told PEOPLE, "Quite honestly, it was Scott coming to me and saying, 'I want to do a climate change Black Mirror, and I've got this amazing cast of actors.' And I was like, 'Yeah, great. I'll be a part of that.' "

He added, "I didn't see a downside to it really. It was an important piece, historical piece, an interesting piece."

Harington also spoke about his character, telling PEOPLE, "The idea with Nicholas Bilton is that he ... was one of those kids from nowhere."

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"A Russian billionaire father, grazed in the British school system... you can't really place him in any part of the world," he said. "And that's fascinating to me because people like that have no affinity or association with any one country."

"So they don't believe in paying taxes to any one place. They want to do their own philanthropy, and that creates its own problem of: they believe they're their own country," he continued. "And I think that's really where Nicholas Bilton comes from — he believes in the free market."

Harington added: "He's a free market capitalist, and he believes that will solve this issue. But he's also, as you will see through the show, incredibly susceptible to being corrupted and corrupting himself and corrupting the whole situation."

Extrapolations also stars Meryl Streep, Sienna Miller, Daveed Diggs, Edward Norton, Diane Lane, Yara Shahidi, Matthew Rhys, Gemma Chan, David Schwimmer, Keri Russell, Marion Cotillard, Forest Whitaker, Tobey Maguire, Adarsh Gourav and Indira Varma.

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The first three episodes of Extrapolations premiere March 17 on Apple TV+, with episodes dropping every Friday through April 21.