This article addresses an issue in the manuscripts analysis of the role of a servant, Justin, in Madame Bovary of Flaubert. He has been considered as a character of minor importance. However, his name often arises in the episodes which determine Emma's fate, from the very beginning of the manuscripts of this book. For example, Emma first realizes the contempt she feels toward her husband when she notices he always carries his knife like a peasant, and mutual love with Leon also originates with Justin's intervention. Rodolphe, looking at Emma nursing Justin who has fainted, decides to tempt her, and he becomes her first lover. This paper provides a consideration to the role of Justin as intermediary who finally leads Emma to her bankruptcy and to her suicide.