The Movie takes viewers back to Spring 1943, as the Battle for the Atlantic rages and an Axis victory seems inevitable. German U-boats patrol the ocean picking off ships, destroying much needed supplies and inflicting heavy casualties. The one hope the Allies have - production of newly developed sonar equipment - is moved to Victory Munitions when the British factories are bombed. Then, in the darkest hour of the war, a new and disturbing menace appears - a saboteur among the factory workers."