Nana is a novel that gives the impression of being bathed, from beginning to end, in the light of gas lamps. These flashes, sometimes intense and sometimes weak, always flickering, often create visual illusions. The reader will become confused, deceived, or taken by surprise, guided by the author through the labyrinths of the inner workings of a theater, the nighttime narrow streets of Paris, the salons of grand mansions, the haunts of prostitutes, drunkards, or the dregs of aristocracy, the cheap hotels, luxury centers, salons, or at the racetrack where all the glitter and the decay of the empire are concentrated.

Nana, a character of profound ambivalence and ambiguity, with astonishing changes and contrasts as a fictional character, is the luxury courtesan that serves as both lever and catalyst, the "Golden Fly" that will seduce and infect an entire society that is already gravely ill, unknowingly and deeply. In the novel, we will watch, step by step and with scientific precision, the disintegration of this society that has not realized, with very few exceptions, that hypocrisy, complacency, meanness, exhibitionism, the waste of wealth and human power, the desperate and blind plunge into the world of pleasures can only lead to a tragic end.

The novel belongs to the Rougon-Macquart cycle, which has the accompanying subtitle "Natural and social history of a family during the Second Empire." The narrative ends in 1870, with the illness and disintegration of the magnificent, almost mythical beauty of Nana, and with her death - a symbolic death that refers to the death of the empire - in the dimly lit room of a hotel, on the very night that war is declared against the Prussians, a symbolic war, like all wars, in the history of France.