Doctor Who has a habit of attracting some impressive guest stars, but one who has been generating a lot of excitement as of late is Game of Thrones cast member Maisie Williams.

The actress will appear in the two episodes, with the first being “The Girl Who Died” this Saturday. Now, the BBC has released a first look clip from this instalment of Doctor Who featuring Williams, along with a few stills of her alongside Peter Capaldi and Jenna Coleman.

The young three-time Screen Actors Guild Awards nominee had this to say about being cast in Doctor Who when filming began earlier this year. “I’m so excited to be working on ‘Doctor Who’ as it’s such a big and important part of British Culture. I can’t wait to meet the cast and crew and start filming, especially as we’ll be shooting not too far from my home town.”

Steven Moffat, writer and producer, added: “We’re thrilled to have Maisie Williams joining us on ‘Doctor Who.’ It’s not possible to say too much about who or what she’s playing, but she is going to challenge the Doctor in very unexpected ways. This time he might just be out of his depth, and we know Maisie is going to give him exactly the right sort of hell.”

This episode of Doctor Who was written by Jamie Mathieson and Steven Moffat, while Ed Bazalgette directs. Be sure to click on the images below to view the full-size versions.