One of the best stories of WWII: the devastation of the heavy water plant at Rjukan in Norway. The Germans made D20 in order to build an atomic bomb. Because of clever intelligence and outstanding survival technics the plant was destroyed. The movie with Kirk Douglas is mostly a fantasy, I am reading the book and viewing the TV series by Ray Mears called the REAL heroes of Telemark and it is still after all those years amazing stuff.