Ellie Harrison and Adam Henson head for the Shetlands, the most northerly inhabited place in the UK. Ellie meets the islanders farming seaweed to eat, tries her hand at an ancient Viking version of chess and goes in search of one of the UK's rarest birds - the red necked phalarope. Adam gets up close to rare native Shetland cattle and sheep, then takes a twirl with a dancing pony. And Tom Heap reports on how a new approach to animal inspections is helping improve welfare on farms