Game of Thrones Season 5 will rule all our lives in less than two weeks’ time, but fan-favorite star Maisie Williams is already looking beyond Westeros for her next gig. The erstwhile Arya Stark will sheathe her sword for a Doctor Who Season 9 guest role, but should fans of either series be worried?

Mum as ever, nether the BBC nor showrunner Steven Moffat would offer any details of Williams’ role, though the actress herself said, “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.”

Adds Moffat:

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.

Williams’ fellow guest stars for the season include Rufas Hound, Tom Stourton, Ariyon Bakare, Simon Lipkin, Ian Conningham, Murray McArthur, Barnaby Kay, John Voce, Struan Rodger, Jemma Redgrave, Kelly Hunter, Clare Higgins, Jaye Griffiths, Daniel Hoffmann-Gill, Jami Reid-Quarrell, Aaron Neil, India Ria Amarteifio, Joey Price, Dasharn Anderson, Harki Bhambra, Demi Papaminas, and a returning Michelle Gomez.

In addition to two-part season premiere “The Magician’s Apprentice” and “The Witch’s Familiar,” Doctor Who Season 9 has also begun filming “The Girl Who Died,” written by Jamie Mathieson and Steven Moffat, followed by the Catherine Tregenna-penned “The Woman Who Lived.”

Between George R.R. Martin’s promise of book-divergent deaths for Game of Thrones Season 5, as well as rumors swirling of Jenna-Louise Coleman’s Doctor Who exit, should we read into Maisie William’s feisty guest role? To whom does Maisie Williams make a better companion, The Hound or The Doctor?