Writer and fisherman Will Millard reaches the end of his journey down the River Taff in South Wales. This beautiful wild river, once neglected and polluted, has now come back to life. Will goes wild swimming with a group of eccentrics trying to change the image of this forgotten river. He meets retired Somali sailors drawn to Cardiff in the city's glory days as a thriving port and tells the story of how the industrial docks have been transformed. Finally, he sets out to catch the king of fish, migratory salmon returning to the river where they were born.