The Doctor has not seen the last of Maisie Williams' Ashildr.

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The ending of "The Woman Who Died" left little doubt that Doctor Who would bring Earth's latest immortal back into play sooner or later, but few fans believed the Game of Thrones star would return before season 9 came to a close. Nevertheless, Ashildr will feature in episode 10, "Face The Raven."

Along with a host of other villainous creatures, Ashildr will find herself trapped on a London street and awaiting a possible death sentence. When the Doctor (Peter Capaldi) and Clara (Jenna Coleman) arrive, however, the former Viking may find an escape.

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"Have you ever found yourself in a street you've never seen before? The next day, could you not find that street again? You weren't dreaming. Your memory isn't playing tricks," executive producer Steven Moffat teased, according to Spoiler TV. "Like many lost souls throughout the ages, you have stumbled on an extraordinary secret - be grateful you survived it. The Doctor and Clara, with their old friend Rigsy, find themselves in a secret alien world, folded away among the streets of London. Not all of them will get out alive. One of the three intruders must face the raven..."

Is someone targeting the universe's most notorious criminals? Ashildr and Twelve have certainly made their fair share of enemies, but what about Clara? Find out more when "Face the Raven" airs on Nov. 21.

Doctor Who airs Saturdays on the BBC and BBC America. Click below to check out a preview for the series' next episode, "The Zygon Inversion."