Deep beneath a mountain in central Germany, a team of underwater explorers dive the ruins of a secret Nazi missile factory. Join the Sea Hunters as they explore underground tunnels flooded since just after World War II, where thousands of men died constructing the Vengeance Weapons of Adolph Hitler.” Germany's defeat in World War I was sealed with the Treaty of Versailles, which restricted the Germans by denying them an effective army, air force or artillery. Soon German generals were exploring loopholes in order to re-arm. Their search led to a small group of amateur rocketry enthusiasts in a suburb of Berlin. In 1932, the most promising of these rocketeers, 20-year-old Wernher von Braun, accepted a position with the Army's weapons development center in Kummersdorf, near Berlin. Von Braun hoped that the army's deep pockets would finance his dream of putting a rocket into space. Two months after von Braun began work with the Wehrmacht, Adolf Hitler was elected Chancellor of Germany. As the Nazis began to re-arm, rocket research began to benefit from increased funding, and eventually, would gain high priority. Hitler was focused on ballistic missiles raining upon enemy cities hundreds of kilometers away.” A large research and manufacturing complex was built amidst the forest at Peenemünde, on an island off Germany's Baltic coast. Today, in the quiet villages nearby, there is little left to remind the visitor that this was once the home of the foremost rocket scientists in the world. The prototypes of this jet-propelled flying bomb, later designated the V1, were first tested here. Eventually manufactured in the thousands, the V1's were launched against targets in Britain and Belgium. Hitler's interest in the program waxed and waned, but when the Allies stepped up their bombing of German cities, he seized upon the missiles as weapons of revenge. The missiles of Peenemünde were given new names. The flying bomb would be known as Vengeance Weapon One; and von Braun's missile would become infamous as the V2.” After an allied raid on Peenemunde a new facility was established for weapons production - ‘Mittelwerk', would occupy tunnels carved into the Harz mountains by decades of gypsum mining. Near the town of Nordhausen, the tunnels extended almost two kilometers into the mountain, providing over one million cubic meters of underground space. The prison laborers lived in the tunnels in a Buchenwald sub-camp given the name ‘Dora'. Soon the name became synonymous with death Join Sea Hunter James Delgado and the Sea Hunter Dive Team as they complete a video survey of the now flooded tunnels of Dora. The main test frame where the V-2s were prepared for launch is now under nine meters of water.