Brilliant German scientist and Nobel Prize winner Werner Heisenberg is accused by the new Nazi regime of being politically “unreliable”. He is about to lose his University position, but when his mother appeals to the mother of SS leader Heinrich Himmler, he is allowed into Uranverein, the secret Nazi nuclear energy project. Heisenberg believes heavy water is needed to control the chain reaction. This component only exists at Norsk Hydro’s factory in Rjukan, Norway. The Second World War has now broken out. As a former scientist at Rjukan, Norwegian professor and reserve officer Leif Tronstad suspects the German motive for their heavy water order. He tries to warn Hydro who ends up shipping the heavy water to France under dramatic circumstances. An elaborate decoy plan was initiated. The plane believed to have valuable cargo on board was forced down over Hamburg by German fighter planes. But in April 1940 Germany invades Norway and orders a doubling of the heavy water production. Tronstad escapes to England to warn the Allies about what he believes is an effort to build a German atom bomb.