At the National Railway Museum, Alex and Peter help get the most famous locomotive in the world, the Flying Scotsman, into steam. The team take a ride of a lifetime as the loco travels along its original route, connecting London and Edinburgh, and Alex finds out what it is like for catering staff with 250 hungry mouths to feed. Peter heads to the Great Central Railway to find out how the railways revolutionised the delivery of mail right across Britain and is put to task on the travelling post office. Ruth finds out what the role of the wheel-tapper entailed and helps to tyre a wheel with a steel band at the South Devon Railway workshop. In Bristol, Alex discovers how the railways were responsible for bringing the nation into sync, as he visits a clock with two minute hands. Meanwhile, Peter learns how the railways brought Britain current news for the first time.