Set in the Parisian underworld and plotted like a detective story, Les Misérables follows Jean Valjean, originally an honest peasant, who has been imprisoned for nineteen years for stealing a loaf of bread to feed his sister's starving family. A hardened criminal upon his release, he eventually reforms, becoming a successful industrialist and town mayor. Despite this, he is haunted by an impulsive former crime and is pursued relentlessly by the police inspector Javert.

Hugo describes early nineteenth-century France with a sweeping power that gives his novel epic stature. Among the most famous chapters are the account of the battle of Waterloo and Valjean's flight through the Paris sewers.