Spoilers for "House of the Dragon" episode 1.

The recent "House of the Dragon" premiere garnered the biggest audience in HBO's history. They hit 9.986 million viewers across HBO and HBO Max. The "Game of Thrones" prequel is set almost 200 years before the birth of Daenerys Targaryen, and the premiere set the stage for the downfall of the house of the dragonriders. Whatever you thought of the final season of "Game of Thrones," it's clear from the viewership that at least some of the naysayers are willing to give this franchise another go.

The first series, based on the books by George R.R. Martin, was full of huge revelations and character deaths, pulling people back in, year after year, episode after episode. It was a juggernaut that captivated audiences, and everyone wanted to know what was coming next. Hearing about a prequel series starring Naomi Watts, and then that it had been scrapped, just made us all more curious about which story was ultimately going to make the cut. Keeping it all a secret was very likely a monumental task.

A common way that studios keep character information and plot points under wraps is having actors audition for fake parts with fake scripts. That is what happened to some of the cast of "House of the Dragon," according to an IndieWire interview with Milly Alcock, who plays a young version of Rhaenyra Targaryen, and Emily Carey, who plays a young Alicent Hightower. (The roles will be played after a 10-year time jump by Emma D'Arcy and Olivia Cooke, respectively.)

'Fake Scripts And Fake People'

Alcock said in the interview that she had no idea what she was auditioning for, recalling, "We didn't even know what the project was, let alone the characters. It was all fake scripts and fake people."

It's actually a pretty normal occurrence, and as a former actor, I just want to add in that it may help your state of mind. Imagine the pressure going in to see if you're going to play the lead in a series that people passionately loved, and then turned away from. That's monumental. The stranger part of all this is what she said next about the size of the roles she and Carey auditioned for. "I found that it was 'Thrones' by the second audition," Alcock said, "and then we didn't really know how big our parts were or who they were until later on in the rehearsal process."

That's more surprising. One would assume the studio and crew would want to give the actors more time to prepare for the amount of work they were about to take on. Still, we don't know at what point in the development and/or writing process the auditions took place. It may have been early enough that the information wasn't set yet.

'You're Young Olivia'

Emily Carey didn't know what she was auditioning for at first either, or the size of her role. She added:

"I found out that it was 'Thrones' before my last audition, when my team got that I was meeting [creators] Ryan [J. Condal] and Miguel [Sapochnik]. My management also represent Olivia Cooke so they clocked it like, 'Okay, we get it. You're young Olivia.' But [I] didn't know how significant a role was going to be until we got the scripts."

In the series, Rhaenyra and Alicent are best friends when they're young. Even in the first episode, though, you can see the reasons that their friendship will be torn apart. Rhaenyra, the daughter of the King (Paddy Considine), is one of the only good options left for the heir, after a tragedy and some of the actions of her uncle Daemon (Matt Smith). Of course, the men of Westeros are extremely hostile to the idea of a woman on the Iron Throne.

Alicent's father is perfectly willing to send her to the King's bed to advance their family's position. If she produces another heir, it could change everything for Rhaenyra. Plus, there is the ick factor of your best friend hooking up with your dad. It sounds like things are going to get very messy in Westeros.

Alcock and Carey will play the roles for the first half of the season, before the 10-year time jump, when we'll get to see how the decisions made in the first half have shaped the way they develop as characters.

"House of the Dragon" is airing weekly, Sunday nights on HBO and HBO Max.

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