Between 543 & 538 million years ago, something remarkable happened. After hundreds of millions of years of gradual & painstaking evolution, suddenly the process exploded into life. For the first time animals evolved hard external parts. For the first time there was evidence of active predation, with both hunters abd hunted rapidly developing both armaments & defences. This is a stunning exploration of the cause of the ' Big Bang' of evolution: the development of the eye & the birth of predation.