The actress joins the 'Game of Thrones' prequel as an older version of Alicent Hightower when the series returns on Sunday.
There's a new queen in Westeros -- sort of. As House of the Dragon's storyline is set to jump ahead 10 years in Sunday's episode, a select group of young actors will be replaced by new age-appropriate performers. Alicent Hightower, who has until now been played by 19-year-old Emily Carey, will now be portrayed by 28-year-old Olivia Cooke.
Cooke addressed the transition and what fans can expect from her character's growing rift with Princess Rhaenyra (formerly played by Milly Alcock, with Emma D'Arcy taking over this week) in an interview on Monday's Jimmy Kimmel Live.
"I wish she was a bit more rubbish at her job so then I could go in and be like, 'Don't worry, guys. I got this,'" Cooke joked about taking over her role from Carey. "But, no. Everyone's going to be devastated."
Cooke reveals that she was the actress to be cast first for the part, but that she and Carey didn't feel the need to collaborate on developing Alicent's mannerisms together.
"I was like, I don't have any leg to stand on telling you how to do the role," she says. "Also, imagine you at 18 -- you feel so different. I was like, 'You go and do your own thing and I'll try to be as good.'"
As Alicent appeared to be coming into her own strength at the end of Sunday's fifth episode, titled "We Light the Way," Cooke teases continued hostility between former besties Alicent and Rhaenyra.
"I can say that the simmering tensions between Rhaenyra and Alicent have atrophied over the 10-year time jump," she teases, "and it's just, you can cut the tension with a knife in Westeros."
The actress also admits that she will be paying close attention to fan reaction to her performance this week -- although she may come to regret it.
"I'll pour a glass of wine, I'll put Twitter on. Have a cry, probably," she quips. "Book a trip somewhere, throw my phone in the ocean, [go] to a small fishing village, grow a beard, start a new life."
House of the Dragon airs Sundays on HBO.