The population of London is horrified by the murder spree being conducted by Jack the Ripper. While Police Commissioner Charles Warren investigates the Ripper murders, another, less well publicized killer is at large.
Tucked away on the inner pages of the daily press, a few articles tell of the strange murders taking place on board the carriages of the much-heralded London Metropolitan Railway. Each murder takes place the day after the Ripper killings, as the murderer appears to be taking advantage of the lack of police resources to tackle two major investigations simultaneously.
Inspector Albert Norris is charged with bringing the railway killer to justice, but clues are few and the killer's motive unclear. He is forced to carry out his investigation 'quietly and without causing a public panic' as the authorities try to maintain confidence in the railway system's safety. The press is being told even less, and Norris can count on little help from above as he attempts to solve the inexplicable series of murders.