Modeste Mignon, a young provincial woman of romantic temperament, imagines herself to be in love with the famous Parisian poet Melchior de Canalis. However, he is not moved by her attentions. He invites his secretary Ernest de la Brière to "deal with the matter". Ernest answers Modeste's letters in his name and acts as her lover, disguised as Canalis. The scene changes dramatically when Ernest discoveres that Modeste is, in fact, a rich heiress. Will he be able to win her heart despite his lie.