A Melvillean roundabout of ambiguity and betrayal in the underworld: Serge Reggiani is an ex-con who suspects his friend of being a stool pigeon—un doulos or “finger man” in French slang—and shoots him. Enter Jean-Paul Belmondo, the actual finger man; or is he? As in Bob le flambeur and Le samouraï, the gangsters display an impassive, underplayed demeanor, increasing a sense of equivocation in characters who, as Jean-Pierre Melville said, “are all double . . . all false.” All this is played out against a stunningly photographed suburban setting of barren expanses, lampposts in the middle of nothingness—a gangster-squatter’s paradise or an existentialist’s dream.