Countryfile is in Buckinghamshire where Matt Baker visits Waddesdon Manor and discovers the Rothschilds, a family that shaped the landscape of the entire county. He explores the legacy left behind by Charles Rothschild, founder of the Wildlife Trust, and he gets his hands dirty on the estate's farm, where cutting-edge environmental experiments are taking place to inform the government's HLS schemes. Ellie Harrison is in Wendover Woods discovering creatures great and small: from tiny, rare Bechstein bats to a monstrous, mythical beast, rarely seen in the wild, but loved by children everywhere! John Craven is finding out about the much-prized and now incredibly rare box wood, which changed the face of printing as we know it. Britain's new high-speed train, HS2, is now on its final approach, and Tom Heap asks the developers of the new line whether they can live up to their environmental promise of no loss to biodiversity. He also meets people from Buckinghamshire and beyond who believe it is bound to have a negative impact on our countryside. Adam Henson visits HM the Queen's Balmoral estate in Scotland on a mission to find a replacement for Eric, his highland bull.