Orphaned with a substantial inheritance at the age of ten, Pauline Quenu is taken from Paris to live with her relatives, Monsieur and Madame Chanteau and their son Lazare, in the village of Bonneville on the wild Normandy coast. Her presence enlivens the household and Pauline is the only one who can ease Chanteau's gout-ridden agony. Her love of life contrasts with the insularity and pessimism that infects the family, especially Lazare, for whom she develops a devoted passion. Gradually, Madame Chanteau starts to take advantage of Pauline's generous nature, and jealousy and resentment threaten to blight all their lives. The arrival of a pretty family friend, Louise, brings tensions to a head.

The twelfth novel in the Rougon Macquart series, The Bright Side of Life is remarkable for its depiction of intense emotions and physical and mental suffering. The precarious location of Bonneville and the changing moods of the sea mirror the turbulent relations of the characters, and as the story unfolds its title comes to seem ever more ironic.