Encircling London like a noose, the M25 is a road to nowhere, but when Iain Sinclair sets out to walk this asphalt loop - keeping within the 'acoustic footprints' - he is determined to find out where the journey will lead him. Stumbling upon converted asylums, industrial and retail parks, ring-fenced government institutions and lost villages, Sinclair discovers a Britain of the fringes, a landscape consumed by developers. London Orbital charts this extraordinary trek and round trip of the soul, revealing the country as you've never seen it before