In Marseille, an armored van transporting funds is attacked by a military commando. Paul Sauvage, then boss of the anti-gang brigade, arrests a mobster in a jewelry store. He thus meets Iris Jansen, who manages the shop, and immediately falls in love with it. Sauvage does not know that the robbers gang is led by Pierre Larrieux, a former DST agent, and that Iris is Larrieux's daughter ...