Berlin 1942: While Europe is drowning in World War II, Werner Heisenberg and the Uranium Association are researching the atomic bomb in a secret project of the Army Weapons Office. For this they need heavy water, which is produced in a factory in occupied Norway. When Norwegian scientist Leif Tronstad learns of this, he warns the Allies. While the Americans plan bombing raids, the British begin training Norwegian special commandos. These are to destroy the factory from the inside, but the plant is closely guarded by the German occupation troops. A fierce battle for the heavy water begins. The critically acclaimed series won 6 Norwegian television awards and set a ratings record in its home country. Werner Heisenberg is given a post in the "Uranverein," the German atomic program at the Kaiser Wilhelm Institute. The physicist is certain that heavy water is needed to control the nuclear chain reaction and thus to build a nuclear reactor. However, this is only produced at the Norsk Hydro plant in Norway. When World War II reaches Norway and the Germans take control of the plant, Norwegian officer and scientist Leif Tronstad is certain: the Germans are working on the atomic bomb. He flees to England to warn the Allies.