Sophie Dirondel, history teacher at the Saint-Cloison-sur-Ermoise, wins the jackpot of a lottery, a 2CV. The good-natured woman is both happy and slightly upset, as she doe not have her driving-license. But she decides to take driving lessons and although she does not prove very gifted she manages to pass the test. She grasps the opportunity to achieve one of her sweetest dreams and, proudly sitting behind her wheel, heads for the City of Light. Alone in Paris, she gets to know Victor Martini, a smooth operator. The man who, in real fact, is the leader of a gang, has no problem bamboozling the naive woman.