A voiceover reveals: ‘And now it’s time for one last bow, like all your other selves. Eleven’s hour is over now, the clock is striking twelve’s.’
(Orla Brady) then declares ‘the siege of Trenzalore is now begun’ before another announces that the ‘Time Lord has entered the trap’.
Who’s companion Clara then instructs a mystery bystander to ‘help him change the future’ and a Dalek observes aloud that ‘The Doctor is regenerating’.
The episode’s official teaser reads: ‘The Doctor must sacrifice everything to save a town called Christmas from the Time Lord’s greatest enemies. A change is going to come, and Silence will fall