The first programme of the series tells the story of Tom Wintringham - the Red Revolutionary - one of the leading journalists of his time, a former communist and freedom fighter from the Spanish civil war. His vision was to mould the Home Guard into a vast guerrilla army. In the unlikely setting of a stately home on the outskirts of London, he established one of the most sophisticated military training centres in the country. Surviving Home Guard veterans explain what life was like and demonstrate how they were trained to tackle the Nazis.

Archaeologist Francis Pryor explores the secret sites and the hidden network of WWII bunkers that riddle Britain and meets the men who built and manned these vast fortifications.

The final film of the series examines Britain's secret resistance army, codenamed the Auxiliary Units. Effectively a suicide squad, no one was expected to survive beyond two weeks.