The pharmacist Bourrachon learns that his wife Adrienne deceives him with Dr. Rigal, whose specialties he sells in his pharmacy. His sister, the authoritarian Mrs. Bruneau, urged him to divorce and introduced Geneviève to substitute Adrienne. But after five months of marriage, Geneviève gives birth to a child whose real father turns out to be Henri, the salesman of the Bourrachon pharmacy. Mrs Bruneau will then try to persuade her brother to bring an action disavowal of paternity for the honor of the family and especially to protect the inheritance of his own daughters. But Bourrachon will eventually become attached to the child and endorse his paternity.