Starting in the cab of Puffing Billy, the world's oldest surviving steam locomotive, Chris Tarrant looks at the lives of two leading railway pioneers and the navvies who dug the tunnels and laid the tracks. He also reveals how rail changed the food we eat, and learns how a disaster in Armagh led the government to impose national safety standards.

The railways played a crucial role during the two world wars. The factories were converted to produce munitions, the lines kept vital supply lines open, carried troops to and from the front line, and its underground stations became bomb shelters. There were heroes, but also victims as the railways became an enemy target.

Chris Tarrant tells the story of how the engines that had made Britain finally ran out of steam, the devastating effect of the Beeching Report, how the railways were reinvented for the modern age, and how a sleek new locomotive not only saved the railway network, but reshaped the country.