Secret WW2 expeditions - The Heroes of Telemark
Operation "Gunnerside" was the second British plan during World War II to destroy the Vemork heavy-water plant of Norsk Hydro at Rjukan in Norway by means of a secret sabotage attack carried out by the Royal Engineer Commands.
After the German invasion of Norway this factory was under the control of the Nazis who started a secret program to design an atomic bomb.