Former Royal Marine Arthur Williams walks across Britain to learn about World War II, and he begins his adventure in the port city of Liverpool.

Arthur travels to South Devon to learn about the visitors that wound up in the region, including thousands of London's evacuee children.

Arthur Williams explores London, starting out at St Paul's Cathedral, which became the iconic symbol of the blitz. At Soho's Café de Paris, he learns how the blackout affected the capital's nightlife, and visits London Zoo, to find out how the animals coped during the bombing.

Arthur learns about the secret operations that occurred in Hampshire during the war. He heads deep underground to discover how the London Transport Board kept London moving, and how underground tunnels kept Londoners safe from the bombs. At Senate House he discovers the true story of the Ministry of Information before heading to London Zoo to discover what role the animals played in keeping spirits up. Finally, he visits the Central London Mosque, to find out how the war changed London forever.

Arthur Williams discovers how the people of East Anglia prepared for German invasion, planting mines on the tourist beach at Great Yarmouth building concrete defences and exploding riverbanks at Leiston.

Arthur's journey ends in South Wales, the industrial heartland of wartime Britain, where he learns about barrage balloons that protected the docks and the story of the Bevin Boys.