Paris 1792, a Venetian troupe of actors performs on the banks of the Seine, enacting the Fall of the Bastille and other momentous events, thanks to a new technical gadget, the magic lantern. Elsewhere in the city, the notorious publisher, lecher, bon vivant and writer Restif de la Bretonne returns home from the brothel at dawn, to find his assets seized and his books confiscated. But instead of consoling his daughter with the more than fatherly attention she seems accustomed to, he heads for the coach station: Paris is rife with rumors of the King and Marie Antoinette having fled east, in the direction of the German border. Restif's journalist instinct tells him to follow, but he narrowly misses the coach for Metz, on which the writer Tom Paine, American Revolution participant and here observing the French one, makes his way to Alsace, in search of the steel he needs to build a new type of iron bridge. Also among the travelers are a former magistrate with his Italian opera singer mistress, an Alsace industrialist, an Austrian countess, her black maid and her hairdresser, a widow from Champagne and a student going back to his village.

Restif hires a horse to catch up with the party, but after falling off while overtaking another coach has to be rescued by its occupant, an elderly gentleman by the name of Chevalier de Seingalt, who turns out to be Casanova, himself fleeing from his patron who has sent his servants after him. At each stop the party can observe the commotion that the passage of the mysterious carriage traveling a few hours ahead of them is causing. Opinions are divided about the Revolution, the monarchy, the rights of man and the future of France, but it soon becomes apparent that the Austrian countess and her retinue have a more than passing interest in the King: the countess is one of the Queen's ladies in waiting. Interest, however, focuses on Casanova, his exploits and reputation, with all the ladies making him offers he politely declines on account of advanced age. The mood is light-hearted, the peasants from the fields wave, and the student seduces the black maid high up on the coach. A brief stroll while the coach is being pulled up an incline allows Casanova and the countess to renew an acquaintance one of them never knew existed.