The Secret Battle for Heavy Water. In April of 1940 the Germans invaded Norway and took over the hydro factory in Telemark. Here, heavy water was made for the German's atomic experiments. Thirty years ago tonight nine Norwegian saboteurs, trained in Britain, completely destroyed the heavy water stocks. Wrote Churchill - 'What rewards are to be given to these heroic men?' Theirs was an undercover war which ended with the sinking of a ferry in a Norwegian fjord, fought to prevent the possibility of a German atomic bomb. Reconstructed sequences were filmed at the factory with Norwegian soldiers, and film of the occupation, much not shown before, is also included. Writer PAUL DEHN Narrator Eric Porter