4/6. In wartime, people have gone to extraordinary lengths in their efforts to use the weather as a weapon. Dick Strawbridge illustrates how the Japanese built and sent bombs to America by balloon, and tries to harness solar energy in order to make a sun cannon -the brainchild of an unknown German inventor. Plus an encounter with two "decoy men" -the only Second World War servicemen who actively tried to attract enemy bombs. Series producer Lynn Barlow ; Executive producer Dick Colthurst