The naked body of a strangled man is discovered in a house in Amiens in 1917, and the British Army can't find out who he is or who the murderer is. So they turn to Scotland Yard to cover their backs. Detective Constable Alan McGill and his superior, Inspector Brown, find themselves in France on what seems to be a fools' errand. McGill has other ideas though, and when he suddenly finds himself promoted to Inspector, he determines to solve the mystery. The deeper he delves, the more danger he has to confront, and then, with the mystery solved, he faces a final, deeply disturbing truth.