Series on amateur naturalists focuses on those immersed in the strange and colourful world of butterflies and moths. Changes in the numbers of these creatures reflect wider changes in the British countryside, so studying them is both a consuming passion and a conservation challenge. One enthusiast has walked hundreds of miles to count butterflies; another has devoted his time and his greenhouse to growing one rare butterfly; a thirdis fanatical about moths and has learned to identify all 2500 British species; and one has been getting his hands dirty to restore a chalk down and its butterfly star to their former glory. The programme reveals the highs and lows of British butterflies and moths and gives a window onto the lives of four of the passionate people that are fighting to save them.