Overview: Cameras follow The Jacobite steam train across the Glenfinnan Viaduct. Vloggers Geoff and Vicki, who have visited all 2,567 of Britain's railway stations, board the Caledonian Sleeper on a 24-hour return journey to the UK's highest station at Corrour. Plus, a team of engineers scramble to erect the UK's largest landslide barrier when a slip threatens a section of the world-famous West Highland Line.