Watch: Doctor Who "The Zygon Inversion" Clips
Watch two clips for tonight's episode of Doctor Who "The Zygon Inversion."
Doctor Who airs Saturdays on BBCA.
Shapeshifting Zygons are everywhere in the UK, and there is no way of knowing who to trust. With UNIT neutralized, only the Doctor stands in their way. But how do you stop a war? And what can the Doctor do to save his friends?