Watch Revealed online: Episode 4 The Hunt for Hitler's Scientists

In the closing months of World War II, defeat was looming for the Germans. The invasion of Normandy on June 6, 1944 -- D-Day -- opened a second Allied front, and the Allies began overtaking a host of German positions; Paris was liberated on August 25; Romania and Bulgaria surrendered in quick succession. But the Nazis did not intend to go down without a fight -- and without inflicting as much damage as possible on the Allies. To do so, they employed or planned to employ an increasingly deadly array of military weapons -- from ballistic missiles to rocket planes to, perhaps, the atomic bomb. The British, American, and Russian governments were not content to sit idly by, waiting to be slammed by the advanced technology. Covert teams of commandos and agents were sent ahead of the front lines and deep into Germany, hunting for both the weapons and the scientists and engineers who'd created them. For British and American operatives, failure was not an option. If they didn't capture the Nazi technology and scientists, agents of the burgeoning Soviet Union might -- and that could spell disaster in a post-war world already feeling the chill of the impending cold war.

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