Mere days ago, Whovians celebrated the ten-year anniversary of the regeneration of the long-running British sci-fi series ‘Doctor Who’ in 2005. But now in 2015, the cast featuring Peter Capaldi as the Twelfth Doctor, Jenna Coleman as companion Clara Oswald, and Michelle Gomez as Missy AKA the Master are hard at work shooting the ninth season of New Who (or NuWho). But as we’ve seen in the past, guest stars often join Team TARDIS on their adventures. During season eight, we saw the return of the Paternoster Gang as Neve McIntosh, Catrin Stewart, and Dan Starkey reprised their roles as Madame Vastra, Jenny Flint, and Strax. We also saw Nick Frost of ‘Shaun of the Dead’ and ‘Hot Fuzz’ appear as Santa Claus, but now in Season Nine, fans may recognize the latest guest star from the acclaimed HBO fantasy drama based on the works of George R.R. Martin.

When we last saw Arya Stark on ‘Game of Thrones,’ she was venturing away from Westeros on a boat headed for Bravos. However, it appears that Bravos won’t be the only exotic location on the schedule for Maisie Williams. According to a press release from BBC America, the actress best known for her role as the fearless young Stark will guest star in two episodes that are being billed as “period adventures” titled ‘The Girl Who Died’ and ‘The Woman Who Lived.’ The episodes, which are currently shooting, are written by, respectively, showrunner Steven Moffat and Season Eight writer Jamie Mathieson and former ‘Torchwood’ writer Catherine Tregenna, who happens to be the first female ‘Doctor Who’ writer under Moffat’s regime. On her first day on set, Williams expressed her excitement for landing the currently unspecified role:

“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 [of Bristol, England].”

Though not giving away much about the character either, Steven Moffat added a few vague details about Williams’ character:

“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.”

With ‘Doctor Who’ returning in the fall, we’re likely to get more announcements like these in the coming weeks. But until the next one, what do you think about ‘Game of Thrones’ star Maisie Williams appearing on the show? Based on what the actress and showrunner Steven Moffat have said, do you have any theories about her character? Sound off in the comments below.