The story takes place in Paris around 1895. As Fadinard is on his way to his wedding his horse seizes and devours a straw hat. The owner of the hat is a married woman whom he finds in the arms of her lover, the French officer Tavernier. Tavernier follows Fadinard to his apartment and demands that he find a replacement for the straw hat so that she can return home to her husband without causing suspicion. Because of his fear of Tavenier, Fadinard does everything in his might to find an identical straw hat. When he finally locates a replacement, things get more complicated than before.