While Doctor Who executive producer Steven Moffat wasn’t ready to divulge Maisie Williams’ enigmatic role in the new season, he did go so far as to reveal that “she isn’t playing a returning character or someone in the Doctor’s past. Her role will develop in an unexpected way.” Moffat during his TCA appearance for BBC America today applauded his fellow producer Brian Minchin for conceiving her character, and assured their room that the Doctor Who wasn’t “just going for the star value” in casting the Game Of Thrones actress. Doctor Who returns to BBC America on September 19. Williams appears toward the end of the latest trailer that was dropped at Comic-Con earlier this month.

For quite some time leading up to the new season, BBC has been staging feature film stunts for Doctor Who fans, specifically with Fathom Events. For example, this year on September 15-16, fans can watch the two-part eighth-season finale Doctor Who: Dark Water/Death In Heaven in RealD 3D and Dolby Atmos. The finale is paired with The Doctor’s Meditation, a special prequel scene to the first episode of Season 9, and an exclusive interview with Doctor Who stars Peter Capaldi and Jenna Coleman, hosted by Wil Wheaton.

So, why not just make a Doctor Who feature film already?

Moffat has his concerns over that idea: “First that would be up to the BBC. What are we going to do? Shut down for a year and make a movie? Does everyone want that — a whole movie and not a series? If there’s a movie, you can’t have a different doctor in the movie — that would be incredibly damning to the franchise.”

In November 2013, BBC America released the 50th anniversary 3D episode of Doctor Who, “The Day Of The Doctor” making $10.2M over three days in 15 countries with $4.7M in the U.S. alone at 650 sites. During the final weekend of August last year, BBC America and Fathom exhibited the Season 8 premiere episode of Doctor Who, “Deep Breath” in 550 theaters across the U.S. with bonus footage. No box office results were reported.