Game of Thrones star Maisie Williams has been announced as a guest star in the upcoming Doctor Who series 9 but so far it is not know who she is playing.

Maisie Williams appearance at the end of the trailer for the series had the Doctor seeing her take off headgear and goggles. He says “You!”. Maisie character replies “What took you so long old man?” This resulted in a lot of speculation as to what character she is playing.

Is she the Doctor’s granddaughter Susan? She was left behind after falling in love with a resistance man from Classic Doctor Who‘s “Dalek Invasion Earth“? Or maybe from Series 4 of the more recent run of the show, the Doctor’s daughter Jenny? She set off to have adventures in her own spaceship.

Showrunner was asked about Maisie’s character at the Doctor Who section of the TCAs in LA a few days ago.

Game of Thrones 509 - Maisie Williams
Game of Thrones 509, 49 “The Dance of Dragons” – Braavos secluded waterfront, Arya Stark (Maisie Williams) ©2015 HBO, photo by Macall B Polay

Do you know what character or what type of role Massie Williams will be playing?

Masterpiece Sherlock - Steven Moffat
Doctor Who show runner and Sherlock Co-writer and executive producer Steven Moffat was also at the Television Critics Association Summer Press Tour in Los Angeles, CA on Saturday, August 1, 2015 for PBS Masterpiece series ©2015 PBS, photo by Rahoul Ghose

Do I know? Well Yeah!

Can you tell us?

How relaxed do you think I am?

Yes I do know [but] I can’t really tell you!

Once you see what she is up to in the show, you’ll appreciate what a clever idea of Brian Minchin that was, my co-exec producer, who thought of Massie for this part.

It is a significant part. We are not throwing her away. We not just getting the star value and [not] doing anything with it. It is a great part and she is terrific with it. But, I would say, it will develop in unexpected ways.

One thing that I think is very worth saying, because it keeps coming as an issue, she is not playing a returning character, she is a brand new character. She is not someone from the Doctor’s past.

Unless I am lying, hey!

Doctor Who, Season 9 - Maisie Williams
Doctor Who, Season 9 – Maisie Williams in the TARDiS ©2015 BBC Worldwide