Young Monique leaves the preventorium where Doctor Delaunay has lovingly cared for her. A painful return. Her mother Denise lives with Eugène, a handsome, disreputable young man who's easy to please and, on occasion, won't hesitate to steal. He hangs around Monique, excited by her freshness, until the day he is shot on suspicion of the disappearance of a mobster. Monique is reunited with Dr Delaunay, much to the satisfaction of her guardian Gilbert, known as Patte-en-moins, owner of the local bistro.
Around 1750, in the Dauphiné not far from the Swiss border, a cooper, tired of the injustices affecting the peasants crushed by taxes, went into revolt. Louis Mandrin, a handsome fellow without fear and without reproach, puts himself out of the law by refusing to obey the local nobility. The public authorities are tearing their hair out because the man is elusive. Helped by his faithful friends and by two women in love, Mandrin will become a legend.
When she sets sail for Lisbon, Catherine Laurence, a famous classical singer has but one wish: to be left alone. Unfortunately she soon gets bothered by a rude, invading man. Later she gets to know him better and becomes susceptible to his charm. She realizes that Michel is in love with her and it is not long before she goes beyond her disastrous first impression. Although not quite sure he is a perfectly honest man she entrusts him with a delicate assignment: keep her precious pearl necklace coveted by Van Coolart, a fake Dutch diamond-merchant, and give it back to her in Paris. If he is a robber himself, so much the worse for her. But if Michel keeps the Paris rendezvous love is in store for both of them. Nevertheless there is a crucial factor she regrettably disregards, composer Raymond Aubour, a faithful friend who has been her suitor for ten years.
