Game of Thrones star Maisie Williams has taken a break from her role in the blood-thirsty epic to make a guest appearance in Doctor Who.

The actor, from Bristol, was in Cardiff to film her part in the new series of the long-running BBC sci-fi show which will be on TV later this year.

She 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.”

The show’s boss Steven Moffat said he was “thrilled” to have her on board.

He said: “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.”

The stars of Game of Thrones were in London last month for the world premiere for the show’s fifth series.

Cast members of the fantasy drama including Kit Harington, Gwendoline Christie, Sophie Turner and Alfie Allen attended the launch of the new season at the Tower of London in the capital, ahead of its debut on Sky Atlantic next month.