The story (based on a novel by James Hadley Chase) concerns the efforts of the genial and deceptively tentative Lepski (Michael Brandon), an insurance company detective, to track down a valuable medieval Russian icon, which was stolen by Bradley (David Carradine), a master thief.

Movie star Barbara Jenkins arrives in Cannes to host an auction of her costumes, under protection of Tom Lepski. She is under surveillance of a political terror group and some wily jewel thieves.

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.

Having developed a revolutionary device that puts water in the mouth of all secret services in the world, professor Forrester is about to go on a conference in San Francisco under the protection of Tom Lepski, an insurer.