The Shannon is Ireland's greatest geographical landmark and longest river. It is both a barrier and highway, a silver ribbon holding back the rugged landscapes of the west from the gentler plains to the east. On its journey south, the Shannon passes through a huge palette of rural landscapes, where on little-known backwaters, Ireland's wild animals and plants still thrive as almost nowhere else. For a year, wildlife cameraman Colin Stafford-Johnson lives on the river, camping on its banks, exploring its countless tributaries in a traditional canoe, following the river from dawn to dusk through the four seasons, on a quest to film the natural history of the Shannon as it has never been seen or heard or experienced before.