Professor Alice Roberts, Professor Danielle George and Dr Onyeka Nubia examines surviving evidence of Britain's preparation for a Nazi land invasion during the Second World War, including the tragic story of one of the war's forgotten heroines. Alice learns about the deployment of the Home Guard, and Danielle travels to the Channel Islands to visit the only concentration camp to be built on British soil.

From battlefields and ancient swords to mighty castles and Durham cathedral, the story of William the Conqueror's journey from invader to ruler of England.