Leif Tronstad assembles a sabotage group named Grouse. The aim is to assist the English commandos to blow up the water plant at Vemork. In Germany, Werner Heisenberg continues his work on the atomic reactor. Grouse is dropped over Hardangervidda and prepare a landing for the Englishmen.
Taistelu kuoleman vedestä, La Bataille de l'eau lourde, The Saboteurs, The Heavy Water War: Stopping Hitler's Atomic Bomb, Bitwa o Ciężką Wodę, Heavy Water War, The Heavy Water War