In Paris in 1887, Irène works as a governess to Douce, the grand-daughter of the dowager Countess de Bonafé. Douce believes she is in love with Fabien, the handsome manager of the estate. However she cannot hope to marry him because of their class difference. Douce's widowed father, the Count de Bonafé, has a wooden leg, and is infatuated with Irène. Douce discovers that Fabien is planning to flee to Quebec with Irène, and also finds out that the Count has asked Irène to marry him. So Douce tells Fabien this and convinces him to run away with her, causing consternation in the family.
In a moment of madness a respectable pharmacist kills a young woman who is sun-bathing by a lake. Unable to take in what he has done, he flees from the scene of the crime and behaves as if nothing has happened.
