Michael Portillo continues his postwar Scottish railway adventure, this time from Glasgow to the capital, Edinburgh. At Pollok Country Park in Glasgow, Michael joins a women's running club, the Bellahouston Harriers, for a warm-up session. In parkland above the pits en route to Cuningar Loop, he finds Glasgow's geoenergy observatory, where the British Geological Society is researching how mine water heated naturally underground can be harnessed to save energy. At Livingston North, Michael investigates a puzzling incident in 1979 in Dechmont Woods. And at Edinburgh's famous 12th-century castle, he discovers the origins of a spectacle that has attracted tourists from far and wide since 1950, the Edinburgh Tattoo.