In 1864, Lizzie Martin accepts the position of companion of a wealthy widow, owner of a house in a slum. Lizzie is intrigued to discover that her predecessor has disappeared, presumably on the run with an unknown man. But when the body is found in the ruins of recently demolished houses in a part of the slum directly adjacent to the new prestigious St Pancras station, Lizzie begins to wonder what really happened to the girl. He teams up with a childhood friend, now police inspector Benjamin Ross, and begins investigating the case with his help. Lizzie risks her life, but she wants to find out the truth about the death of a girl whose fate seems to be connected with her own...