More than one billion people use London underground annually, yet few of them know just how haunted the tube really is. We investigate the supernatural secrets of the oldest underground network in the world. Our hair-raising journey takes us through the graves, church crypts and plague pits that tube tunnels have disrupted. We hear the startling stories of the men and women who work one hundred and fifty feet below our capital's pavements; we also scrutinise the network's amazing architecture and exceptional engineering.This remarkable programme enables us to survey one of the most familiar environments in London from a radical and chilling perspective.We hear the supernatural stories of London Underground staff members who man the echoing stations and tunnels at night, long after the commuters have disappeared. For the first time on camera, drivers and station staff discuss their unexplainable subterranean experiences, outlining the effect that the incidents have had on them.