Sarn Helen - Helen's Causeway - is the broken Roman road which runs 160 miles across Wales, connecting south and north. In his first book of non-fiction, acclaimed novelist Tom Bullough walks this route, describes Wales’ changing landscape, and explores the political, cultural and mythical history of a country that has been divided by language and geography. Running alongside this examination is the story of Tom's engagement with the climate crisis and its probable impact on the Welsh coastline.