The story by Steven Moffat will air in the UK on 10th April. The time not confirmed at present, but the talent show Over the Rainbow is scheduled for 6.30-8.00pm, implying Doctor Who could be on as early as 5.45pm.
All schedules are provisional and will be confirmed next Wednesday.
The Doctor takes Amy to the distant future, where she finds Britain in space. Starship UK houses the future of the British people, as they search the stars for a new home. But as Amy explores, she encounters the terrifying Smilers and learns a deadly truth inside the Voting Booth.