Atom Vercorian is trying to make it as a private detective in post-war Paris, and he just needs that one big case to make a name for himself. His father, a police detective, isn't making any headway in the case of a jewelry theft in the south of France. Atom, however, gets a lead that takes him and his partners, Mimi and Jojo, south to Marseille, where they meet ex-resistance fighters, gangsters,