Season 4

With Nazi Germany's rise to power, a long-abandoned canal project in East Prussia is resurrected, but the true purpose of this massive waterway comes into question.

As Hitler's shadow engulfs Europe, ancient castles across the continent fall under Nazi control and are transformed to serve the ambitions of the Third Reich.

In 1942, a mysterious technology is facilitating a deadly Blitz. Desperate for answers, British intelligence sets its sights on an installation in Bruneval, France.

As Allied bombing raids escalate, a massive concrete dome rises from the French countryside, reportedly concealing a crucial component of Hitler's plan.

After the Allied landing in Normandy, France falls city after city - but a small island fortress off the coast becomes the stage for a harrowing act of Nazi defiance.

Deep in the forests of East Prussia, a sprawling Nazi complex becomes the nerve centre of Hitler's empire - and the site of a daring plot against the Fuhrer.