The team explore the magnificent South Downs. Matt Baker meets the pony who's blazing a trail across this landscape. Helen Skelton discovers why dark skies are so important for our wildlife. John Craven visits Charleston House, the rural retreat of the Bloomsbury Group. And Adam Henson looks at a new and novel way to stop cattle from roaming.A courgette crisis, a lack of lettuce and rationing on our supermarket shelves, just what is going on behind the scenes of Britain's veg crisis? Tom Heap heads to Spain to find out what's gone wrong and to discover what we can do keep our food supply secure.