With the French occupants a theater company also arrives from Paris, introducing the novelty of real women for female roles. Due to the obtuseness of the Roman people the show proves a failure, but Onofrio takes the chance to start an affair with the beautiful and free spirited singer Olympia. One night, while walking around the ruins of the Forum to find a suitable spot for sleeping together, they notice a drunken coalman who is a perfect sosia of the Marquis. Onofrio decides to play one of his jokes by switching roles. He instructs his servant to have the unconscious man dressed up as himself, while he will play the part of Gasperino the coalman. The next morning the poor drunkard wakes up in Onofrio's bed to find himself transformed into a marquis. His bad manners lead the family to believe that he is possessed by the spirit of a dead coalman, and Onofrio's uncle tries to have him exorcised. After the first shock Gasperino starts to adapt to his new role and some of his family find him even better than the real Marquis. But when the Pope returns after Napoleon's defeat he has Onofrio condemned and Gasperino risks to end his life under the guillotine.