It's hard to imagine the destruction the world might have seen had the Nazis had access to nuclear weapons, in 1943 this seemed like a real possibility. Nestled in the Norwegian hillside was a facility that could provide the Nazis with another piece to their nuclear puzzle: heavy water. Vemork Hydro Plant had a giant store and the ability to produce more. With the threat of the nuclear weapons looming, the Allies would plan and carry out Operation Gunnerside, the most successful act of sabotage in WWII. A daring mission to thwart Hitler's atomic bomb. It would require skis, scaling equipment and explosives and the sacrifice of many brave men.