'Audio Obscura is more hypnotic than it first sounds - these muttered confessions might even make you miss your train...' - Clara Tait, Time Out At a railway station, everyday dramas are constantly being played out: meeting, parting, anticipating, escaping. The atmosphere is an odd mix of tension and contemplation. Everyone is waiting for something to happen or moving between events. In a station we are forced into proximity. We observe one another yet behave as if being in a crowd confers invisibility. We tend to assume that we are neither overheard nor overlooked. This book derives from a sound work, also called Audio Obscura. Commissioned by Artangel and Manchester International Festival, it was created for Manchester, Piccadilly and St Pancras International stations, where these photographs were taken. The idea comes from the camera obscura, or "dark room", a once popular form of entertainment and artist's tool which uses a small aperture and mirrors to project a reflection of the passing world. A form of proto-cinema, the camera obscura was in part what led to early photography, as people strove to fix the images it produced. As Lavinia Greenlaw writes in her introduction, "All of my work has, in one form or another, been an exploration of the point at which we start to make sense of things; an attempt to arrest and investigate that moment, to separate its components and test their effects. Audio Obscura extends this to the act of listening, or dark listening, in which unconscious aspects of perception are brought to light in ourselves."