Doctor Who's Twelve will have a deadly decision to make in the season 9 opener, and the venerable time travler is poised to make a grave mistake.

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Steven Moffat's "The Magician's Apprentice" and "The Witch's Familiar" will bring Davros, aka the baddie who created the Who's signature Daleks, back into the picture. This won't be the Davros the Doctor (Peter Capaldi) has come to know and hate, however.

Instead, Twelve will come face-to-face with the young boy who would grow up to leave a trail of carnage across the universe.

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"The Doctor is about to make a mistake that has cataclysmic repercussions," Capaldi told The Mirror. "[There is] a conflict which is central to his being."

Could this new regeneration really smite a child? Even if he could, would the repercussions be worth it? Surely the evolution of the Daleks is a fixed point, and we all know what happens when you disrupt the inevitable.

Find out more when Doctor Who returns to the BBC and BBC America this fall. Click the video below to see the Doctor and the Daleks from past seasons.