Actress Naomi Watts. (Photo by Arthur Mola/Invision/AP)

The hit HBO fantasy drama is set to come to a dramatic end on Sunday, but fans won't have to mourn the show's loss for long, as the "Game of Thrones" prequel starring Naomi Watts has begun filming in Belfast, under the working title "Bloodmoon".

Watts was confirmed as a cast member last year. At the time, she revealed that while she wasn't following the globally popular show, she had a binge-watch session on her to-do list.

Producers have been keeping mum on the details of the characters, but here are four things we know about Watts' character, so far:

  1. The Australian actress will play a "socialite" in the much-anticipated prequel. 
  2. She has a dark secret.
  3. Fan theorists are speculating online that she will play Nissa, wife of Azor "Lord of Light" Ahai, a leading figure of the faith of R’hllor.
  4. Watts will act across lead man, Josh Whitehouse. Legend has it, Azor, forged the magical sword Lightbringer by plunging it through the heart of his beloved in order to defeat the White Walkers.

According to reports, "Bloodmoons" plot is set more than 5 000 years before the events of the current series, the new series will follow the story of the "Children Of The Forest."

Since George R.R. Martin confirmed the upcoming 'Game of Thrones' spin-off last November, several other cast members have been announced, many of whom are familiar within epic fantasy. Jamie Campbell Bower (Harry Potter and the Deathly Hallows Part 1), Georgie Henley (The Chronicles of Narnia) and Miranda Richardson (Harry Potter and the Goblet of Fire).

The show is expected to premiere by mid-2020.