The season five premiere of Game of Thrones is only a couple weeks away, but Maisie Williams already has a new project to look forward to! The actress will guest star on Doctor Who, BBC's mystery series. "We're thrilled to have Maisie Williams joining us on Doctor Who," said executive producer Steven Moffat. "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 just got interesting!