Thérèse Ravenaz is a charming young woman but also the victim of a seducer who abandoned her as soon as she told him that she was expecting his baby. To trace her unworthy lover, she boards a taxi driven by friendly cabdriver Emile Gauthier, who agrees to help her. But street after street, district after district, the seducer is nowhere to be found in Paris. And when she finally achieves the end of her quest, there is no Holy Grail. She learns that the rotter is already married. Fortunately, Emile has a heart of gold.