Williams will soon be set to take on the role of Viking-turned-immortal Ashildir for the third time. As reported by The Mirror, Maisie William’s next appearance on Doctor Who will be in the tenth episode of Season 9, forebodingly entitled “Fear The Raven." As “Fear The Raven” also happens to be the episode confirmed to see the departure of Jenna Coleman as Clara from the T.A.R.D.I.S., it seems that Ashildir will have a role in the events surrounding what looks as if it may be the first permanent death of a companion since the series was rebooted in 2005.
Maisie Williams has previously appeared twice in Season 9 of Doctor Who as an ally to the Doctor and his current companion Clara. Her first appearance saw her saving her village from an alien invasion result in her death, which itself resulted in the Doctor bringing her back to life as an immortal. Her second appearance saw the character pop up several hundred years later jaded by her immortality. Ultimately, she decided that her new purpose will be to keep an eye on the aftermath of a visit from the Doctor to Earth
The young actress has been highly anticipated in her appearances on Doctor Who, which comes as no surprise. Maisie Williams came to Who with her own fanbase from her role on HBO’s Game of Thrones. The last image of Ashildir in her second appearance, however, was received far less enthusiastically. Popping up in the background of a selfie of Clara's, Ashildir’s presence gave rise to the question of whether or not Clara would be meeting an untimely end in the near future.
Of course, there are ways to knock companions out of the way without killing them. Aside from a temporary stint in Season 4, Rose Tyler has been trapped in a parallel world since the end of Season 2. Donna Noble was forced to forget her adventures with the Doctor in Season 4. Amy and Rory were locked away into 20th century New York to live and die without seeing the Doctor again. Some goodbyes are forever in Doctor Who without death coming into play.
If the reports don't hold up to scrutiny, Clara may be one of those companions to escape and survive. Either way, it is improbable at this point that Maisie Williams will be taking on the role as the next companion to the twelfth incarnation of the Doctor. Still, there's no reason not to imagine that she couldn't bring the immortal Ashildir back to our screens in some capacity in the future. We'll just have to wait, hope, and see.