Doctor Who's eponymous Time Lord is out to save humanity once more, but the Doctor may put an innocent life in danger to do so.

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In the near future, Twelve (Peter Capaldi), Clara (Jenna Louise Coleman), and the young Courtney (Ellis George) will popup on a shuttle heading for the moon - and certain disaster. A lunar mining colony full of corpses and some ridiculously oversized spiders await them on the surface while the shuttle and it's crew carry enough nuclear charges to destroy Earth's satellite.

With someone's life hanging in the balance, the Doctor will have to make a crucial decision - one that may shock Clara to the core.

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"Perhaps more than any episode so far this series, we'll see just how alien this new Doctor is," said writer Peter Harness, according to Doctor Who Magazine (via CultBox). "By the end of this episode - and I know we say this kind of thing a lot, but believe us - things will never be the same again. I still don't know how people will take it. I've never see the Doctor do something like this before."

With the Doctor not quite his usual self, Clara will have to keep herself and her student safe while they rush to choose a course of action

"We have a terrible decision to make," Coleman told Doctor Who Magazine (via Blogtorwho). "It's an uncertain decision, and we don't have a lot of time. The man who normally helps - he's gone. Maybe he's not coming back. In fact, I really don't think he is. We're on our own..."

Scroll through the photos above and click the video below to see what the Doctor and Clara will do next.

Find out more when Doctor Who airs Saturdays on the BBC and BBC America.