Michael Portillo takes to the tracks with a copy of George Bradshaw's Victorian Railway Guidebook. Portillo travels the length and breadth of the country to see how the railways changed us, and what of Bradshaw's Britain remains, as his journey follows the route of the Irish mail from Ledbury to Holyhead. Michael explores the Conwy valley, stopping at Britain's first artists' colony at Betwys-y-Coed, visiting the Victorian slate capital of Blaenau Ffestiniog and taking a steam train down to the harbour at Porthmadog.