The Windmill is a flat-roofed pub in Brixton that for the past two decades has been at the epicentre of the capital's underground music scene. Everyone from Mica Levi to Fat White Family to Black Midi has passed through its doors, which are presided over by a series of roof dogs including the legendary Ben the Rottweiler. With the help of impressionistic sketches by his son Otto, Will Hodgkinson goes on a spiritual journey to the heart of the Windmill, seeking to understand why this former Irish boozer has become such a magical space of freedom and discovery.