A butterfly flutters its fragile wings in Texas and the seemingly imperceptible turbulence sets in motion a cascade of effects that culminates in a typhoon in Indonesia. It seems unreal. But the realisation of the butterfly effect as it has been called, is one of the astonishing results of the new science of Chaos. Traditionally science has been focused on seeking out and defining the predictable laws that govern all our lives. Chaos is about using the immense number crunching power of super computers to seek out the patterns hidden away in what up till now has been totally unpredictable. This astounding, award-winning documentary lays bare the mystery of this remarkable new science. The factories of the Ruhr were crippled. 1300 German civilians died, and 53 aircrew were lost. For the very first time this programme explores both sides of a raid that has become an epic in the history of World War 2.