This time Jeremy's on the Severn, the longest river in Britain, flowing through the heartlands of both England and Wales. He meets the last mudhorse fisherman on the Severn Sea, investigates the country's largest ship graveyard, stops off for a glass or two of organic Worcestershire wine and, after demonstrating quite extraordinary levels of ineptitude at a coracle regatta, is greeted by a poet at the Severn's source, in the watershed of Wales.