As US troops approached a Nazi prison camp, they could hear agonized wailing. The stench of rotting flesh filled their nostrils. Moments later they discovered a pile of smoldering corpses, alongside emaciated survivors.

Next to the concentration camp they found something else: tunnels filled with tools — and partially assembled rockets. The soldiers had hit upon the evil heart of the V2 manufacturing program: enslaved laborers, imprisoned underground.

And the rocket program's director? Wernher von Braun had already fled. He now had just one concern: persuading the Americans to let him switch sides…

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