Doctor Who fans are used to their favourite Time Lord getting into all sorts of dubious goings-on, but even they may be forced to ponder his motives in a forthcoming episode, where the Doctor appears to "save" Adolf Hitler.
At one point, the reviled dictator, played by Albert Welling, even tells the Doctor: "Thank you, I think you just saved my life."
The episode, which was given a sneak preview at sci-fi fans' paradise Comic Con in the US at the weekend, will be aired in the UK when the series returns in the autumn.
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