'Game of Thrones'
A poster of HBO TV series "Game of Thrones." Game of Thrones/ Facebook

Casting for the first “Game of Thrones” spin-off continues. Actors Sheila Atim and Denise Gough are reportedly being considered for unspecified roles. Both the actors have extensive theater experience, and they both have won Oliver Awards for their performance in West End Theater.

According to a report by ThatHashtagShow, Atim and Gough are being considered for unspecified roles in the spin-off. Atim has worked in Director Adam Smethurst’s adaptation of Shakespeare’s drama “Twelfth Night” and she is being considered as a rising star in London’s theatrical community.

Irish actress Gough was seen recently in the UK thriller “Steel Country.” The actress is said to be cast in a “critical” role in the TV series, but character description or other details have not been revealed yet.

Negotiations are said to be taking place with both the actors, and no deal has been signed yet. If they come on board, they will be joining the two other actors who have already been cast- Naomi Watts and Josh Whitehouse.

Watts’ character has been described as a “charismatic socialite” who is hiding a “dark secret.” No details about “Poldark” star Whitehouse’s character have been revealed.

The plot of the spin-off is set a few thousand years before the events in the current “Game of Thrones” TV series. This is during the end of the Golden Age of Heroes and the beginning of the Long Night.

“The Long Night” is expected to be the title of the spin-off, but HBO is yet to choose a title. The pilot episode of the show is set to be filmed between February and March next year. The rest of the episodes will be filmed a few months later in July. The show is only expected to premiere sometime in 2020. The producers are yet to announce an exact release date.