At the outbreak of the war, the Nazis had the finest air force in the world. Just five years later it was a broken fleet. Why?

James goes to the depths with Germany's Wolf Packs, the U-boats, the force that most threatened wartime Britain's survival - from suicidal one-man torpedoes to the potentially game-changing Type XXI

James explores just how effective German weaponry was in battle conditions and uncovers the secret flaws the Nazis tried to hide