From the producers: Ghosts on the Underground is a journey through the oldest Underground network in the world. One billion people a year descend 150 feet below London into the tunnels and stations of the tube without a second thought for the huge number of deaths on the network and the graves, church crypts and plague pits that the Underground has disrupted over the years. Ghosts on the Underground shows previously unheard accounts from the people who actually work on the network, who talk for the first time on camera about their unexplainable experiences. Along the way, the program explores the more unusual nooks and crannies of the network, showing the amazing old and new architecture of the world's largest Underground network, and revealing that although millions think they know the network, none of them know just how haunted the tube really is.