Fresh from the front lines of the Great War, newly commissioned lieutenant Eve "Chance" Masters has been recruited into a shadow branch of the Entente military machine. The Special Courier Service is a clandestine counter-partisan unit tasked with rooting out enemy agents and dealing with supernatural cases that others cannot, or will not handle themselves. Chance expects to deal only with the violent Apache gangs of Paris, but her mission goes on a startling tangent when she unearths clues pointing to the whereabouts of a forgotten, long-lost national relic. However, with no extant records or witnesses, she turns to her last resort: talking with the dead.