Maisie Williams stars in new 'Doctor Who' trailer

Maisie Williams steals the spotlight in a new Doctor Who season 9 trailer.

The preview features the 18-year-old English actress in her upcoming, as-of-yet unspecified guest role. The Game of Thrones star is confirmed to appear in two episodes of the forthcoming season.

"I'm so excited to be working on Doctor Who as it's such a big and important part of British culture," Williams previously told BBC America. Executive producer Steven Moffat added, "She is going to challenge the Doctor in very unexpected ways."

The teaser stars Peter Capaldi and Jenna Coleman as the Twelfth Doctor and Clara Oswald, respectively, with Michelle Gomez as Missy. Coleman confirmed she will appear on season 9 in December 2014 amid rumors of her departure.

Doctor Who has been a staple for the network since its original premiere in 1963. The sci-fi drama ran for 26 consecutive seasons, and was revived in 2005. Capaldi debuted as the latest incarnation of the Doctor, an alien who travels through space and time, in season 8.