After what appeared to be rather lengthy negotiations, two-time Academy Award nominee Naomi Watts has signed on to play a lead role in an upcoming HBO "Game of Thrones" prequel series, Variety reports.

This as yet untitled brainchild of Jane Goldman (who is also a showrunner) and George R. R. Martin is set to begin filming in February next year after its pilot was ordered over the summer. The series is expected to premiere sometime during 2020, though nothing has been officially confirmed yet.

Watts' role is obviously shrouded in mystery at this point. But the official description of her character has been revealed, though.

Let's check it out.

Who is Naomi Watts playing in Game of Thrones prequel?

Well, that's a million dollar question right there. But we do know thanks to Variety that she will be playing "a charismatic socialite hiding a dark secret." Talk about mysterious, huh?

The filming hasn't even started yet, but judging by these descriptions they keep revealing, we are in for a treat. So maybe, just maybe, "Game of Thrones" might get a worthy successor, after all.

What we know about the prequel so far

HBO has already confirmed earlier this year that this prequel, in particular, will cover the Age of Heroes and its descent into the Long Night. The series might not have an official title yet, but it's worth noting that George R. R. Martin would want it to be called "The Long Night."

We'll also learn more about the mysterious Essos, the Stark ancestors, and, of course, true origins of the white walkers, which according to HBO, "is not the story we think we know."

That right there, straight up tells us that there's more to the white walkers' origin story than what we are led to believe after the Night King [VIDEO]'s creation scene all the way back in "Game of Thrones" season six's "The Door" episode.

And I can't help but feel that Naomi Watts' character is somehow tied to the mysterious undead beings. After all, according to the description, her character is supposed to hide a dark secret, and that, at least in my opinion, has "white walkers" written all over it.

More names expected to be announced soon

As George R. R. Martin, the author of the "A Song of Ice and Fire" books and the series co-creator, wrote on his "Not a Blog," more names will be announced soon.

Martin also confirmed that there are also a couple of other prequels in active development, though he couldn't say what they will be about.

"Game of Thrones" season 8 will air during the first half of 2019 [VIDEO], the prequel is not expected to arrive until 2020.