There isn't much that fans love more than a good crossover, where two of their favorite properties merge, resulting in something unexpected and awesome. Failing that, fans can also dig when an actor from one incredibly popular show turns up another hit genre show, as will be the case when Game of Thrones' Maisie Williams guest stars on next season of Doctor Who.
Williams will appear in two episodes of Doctor Who season 9 - “The Girl Who Died” and “The Woman Who Lived” - however, the details of her role remain a mystery. The first image shared of Williams on set was merely a publicity shot and didn't hint much at her character. Then she showed up in the Doctor Who Season 9 trailer during its post-logo stinger in a quick scene that implied the Doctor knows her character, and that he knows she's trouble.
There has since been rabid speculation over just who Williams is playing, and given the hint of familiarity between her and the Doctor, many theories - including a few of our own - have suggested her character is perhaps a young Missy, the Doctor's artificially progenerated daughter Jenny, or even his actual granddaughter, Susan Foreman. But during BBC America's presentation at the TCAs, Doctor Who executive producer Steven Moffat put many of these theories to rest by insisting that Williams' role is not a returning character.
— Yahoo TV (@YahooTV) July 31, 2015
The statement nixes a lot more than the Doctor's daughter theory, though that possibility was probably the most appealing given how well liked Jenny's character was and how many fans are interested in what happened after she took off in that rocket ship. But if Williams' character is not a returning one, then there's no way she can be Missy, Susan, River Song, or other Time Lords from the original series like The Rani or Romana. That is, of course, assuming Moffat isn't lying - always a distinct possibility.
If we assume Moffat is being straight with us, then Williams' character must be someone entirely new - at least for the audience. Their exchange in the trailer implies the Doctor knows Williams' character, but there's plenty the Doctor knows that we don't. For instance, a pair of real evildoers from the Time War - characters the Tenth Doctor refers to as the Could've Been King and The Nightmare Child - have cropped up as real possibilities given that with Gallifrey's time lock broken, there's a chance they've escaped to wreak havoc on the universe once again.
Moffat has also implied season 9 will find the Doctor and Clara "having absolutely the best time ever," before everything goes terribly wrong. What better way to spoil all that fun than by introducing a really nasty villain - and having them played by the adorable Maisie Williams?
Hearing that Williams is not playing a returning character, what new theories do you have about the identity of her mystery role? Let us know what you think in the comments below!
Doctor Who returns to BBC and BBC America on September 19th 2015.
Source: Yahoo TV