During the Indochina War, Lieutenant Perrin and his men, French soldiers, hold a remote post. They lived in harmony with the local population. Over time, they have managed to forge a peaceful relationship with the villagers. The French have built a school and a dispensary. But all their efforts are suddenly wiped out when Viet Minh resistance fighters storm their post.

Four murders in forty-eight hours happen in Nice. The murderer calls himself "The Exterminator" and the police are unable to catch him. Tom Lepski is an insurance detective and he get involved in the investigation when Liza Mendoza, a famous violinist and a friend, is killed just a few minutes before Tom visit her. After another rich woman killing, Tom finds out that all the victims were members of the exclusive Fifty Club. All of them but Lisa.

In August 1952, a family of British tourists is found by the roadside in Haute Provence, brutally murdered. In the ensuing, very public, investigation a local landowner, 75 year old Gaston Dominici, is arrested for the murders, having been denounced by his sons. Under police interrogation, Dominici confesses to have killed the family and it looks certain that he will be charged, tried and sentenced to death. But then the case begins to collapse. The old man retracts his confession and the lack of evidence against him becomes apparent…