Michael Portillo takes to the tracks with a copy of George Bradshaw's Victorian Railway Guidebook. In a series of four epic journeys, he travels the length and breadth of the country to see how the railways changed us, and what of Bradshaw's Britain remains. His journey takes him along the Brunel's Great Western Railway from Swindon to Penzance. This time, Michael visits the largest clay mine in the world near St Austell, goes pilchard fishing in Mevagissey and finds out how the estate of Heligan shaped British gardens.