Paris, during the bloodiest days of the Revolution: a book entitled An Atheists' Bible is discovered by the authorities.
But what is An Atheists' Bible and who wrote this 'profoundly reactionary and perversely pornographic' book? It is set in 1759, when the government of Louis XV was in the process of banning Diderot's great Encyclopédie and the Seven Years War was raging, and purports to be a true account of how the printer Bageuret discovers a secret cache of the Encyclopédie in a Parisian warehouse and teams up with the aristocratic twins, Gilles and Sophie Françoise d'Argenson, to sell them.
But finding buyers and smuggling the Encyclopédie of Paris proves more difficult than anticipated. It has many enemies, including the Jesuit General and the fanatic Brass Head de la Haye, who are determined to see the death of the abomination. And Paris is a city of spies and informers, a heaving metropolis where the notorious cabinet noir tries to keep tabs on everything that happens in the black market for illegal books.