Plot: Paris. Tony, nicknamed Le Stéphanois after his hometown Saint-Étienne, has just been released from prison after five years, time served for a jewel heist. He did not give up his younger friend and associate Jo - Le Suedois (The Swede) - in loyalty and to give Jo a chance at life, which now includes a wife, Louise, and five year old son, Tonio, named after Tony. The first of Tony's tasks is to get back at some people, including his old girlfriend Mado in she not waiting for him, she who has taken up with gangster nightclub owner Louis Grutter - Le Tatoué (The Tattoo). His second task is to find something to do to earn money as gambling won't cut it. His and Jo's friend, Mario Ferrati, suggests something akin to a smash and grab of the three stones in the window of the high end jewelry store, Mappin and Webb. Initially declining the offer, Tony agrees only in making it a true heist to rob their safe instead, employing a fourth, a top end safe-cracker, Cesar - Le Milanais (The Milanese). Tony has a plan all mapped out to conduct the heist in the middle of the night, they needing to complete the job by 05:00 at the latest not to arouse suspicion to neighboring businesses which would just begin to open. The biggest issue with the plan is not tripping the temperamental alarm which can be set off by a power failure or excessive vibration. Even if they are able to get the jewels out of the safe, the amount of which they are unaware, and escape, they still have to be careful in not bringing attention to themselves until they are able to fence the goods and get the money. Even if all four of them are able to adhere to these strict post-heist rules, they cannot control their pasts catching up with them, Tony who has the most potential baggage to cause problems.
Alternative Plot: Out of prison after a five-year stretch, jewel thief Tony (Jean Servais) turns down a quick job his friend Jo (Carl Mohner) offers him, until he discovers that his old girlfriend Mado (Marie Sabouret) has become the lover of local gangster Pierre Grutter (Marcel Lupovici) during Tony's absence. Expanding a minor smash-and-grab into a full-scale jewel heist, Tony and his crew appear to get away clean, but their actions after the job is completed threaten the lives of everyone involved.