Back from the pen, homme dur Jean Servais first belts around his ex-girlfriend Marie Sabouret, then rejoins copain Carl Möhner and cohort Robert Manuel, who’ve got a little jewel store smash-and-grab job lined up — but Servais wants the whole works. With the aid of freshly imported safecracker “César the Milanese” (director Dassin billed as “Perlo Vita”), the resulting classic heist — a legendary 30-minute sequence with no dialogue or music — provided a usable blueprint for real-life professionals (causing outright bans in some countries) — but then, another of Sabouret’s ex-boyfriends wants a big cut.