“The Doctor has been summoned by an old friend, but in the Cabinet War Rooms far below the streets of blitz-torn London, it’s his oldest enemy he finds waiting for him, as the time-travelling adventures continue. The Daleks are back – but can Winston Churchill be in league with them?”

Written by Mark Gatiss and guest starring Ian McNeice as Winston Churchill, the episode airs at 6.30pm on Saturday 17th April.