Tronstad establishes contact with the War Ministry and a plan to destroy the Hydro facilities is drawn up; in Rjukan, new managing director Erik Henriksen is confronted with sabotage of the heavy water facility.

The Americans insist on bombing the heavy water factory, but Tronstad persuades the Allies to send in a team of Norwegians instead; in Germany, Nobel Prize winner Werner Heisenberg promises a breakthrough in the development of a Nazi atomic bomb.

Heisenberg is promised unlimited support from the military; the Allies abandon their plan to shoot their way into the heavy water factory, and instead try to climb their way in.