Macilente, disgusted by the injustices of society, flees to the country. As he lies idly under a tree he overhears a conversation between the wealthy young farmer, Sogliardo, and Carlo Buffone, a railing cynic whom the rustic bumpkin chooses as his guide in becoming a gentleman. Macilente winces at Sogliardo’s presumption and at Buffone’s callous instructions to the foolish Sogliardo. Buffone, seeing Macilente and knowing him to be a malcontent, hurries away with Sogliardo, but in departing he tells Macilente that they are going to Puntarvolo’s house.

Still musing under the tree, Macilente next listens while Sordido, a miserly farmer, consults his almanac and hopes for rainy weather in order that his hoarded grain might soar in value. A farmhand delivers to Sordido a note, an official order for him to bring his grain to market. Sordido scorns the order and swears that he will hide his surplus harvest.

In front of Puntarvolo’s house, Buffone and Sogliardo talk with the braggart courtier, Sir Fastidious Brisk. The three watch with amazement Puntarvolo’s return from the hunt. Puntarvolo, an old-fashioned fantastic knight, is given to extravagances in the form of little homecoming plays which he writes himself. Assuming the role of a strange knight, Puntarvolo approaches his house, inquires about the owner, and hears his virtues praised by his indulgent wife and her women. In another part of the play Puntarvolo woos his wife in the manner of a knight-errant. Sordido and his son, Fungoso, a law student in the city, appear. Fungoso is so impressed with the stylish cut of Brisk’s clothes that he asks his uncle, Sogliardo, to get him money from Sordido, ostensibly for law books but actually for a suit of clothes in the latest style. All the while hoping for rain, Sordido reluctantly gives his son money, but not enough.

Reaction varies to Puntarvolo’s announcement that he wagered five thousand pounds at five-to-one odds that he and his wife and their dog can travel to Constantinople and back without a fatal mishap. Buffone sees in this venture material for a colossal joke, while Brisk is interested in investing a hundred pounds in the venture. Fungoso, meanwhile, taken with Brisk’s courtly manner and dress, is pleased to learn that his brother-in-law, Deliro, is Brisk’s merchant.

The next day Macilente advises his friend Deliro to exercise some control in his doting love for his wife, since this dotage causes the wife, Fallace, to react petulantly to Deliro’s affections. Fungoso, wearing a new suit, goes to Deliro’s house and borrows money from his sister, Fallace, in order to complete his costume. No sooner does he receive the money than Brisk enters in a new suit. Fungoso, frustrated by this new development, writes his father for more money. Brisk, meanwhile, brags of his actually nonexistent triumphs at court; he also makes arrangements with Deliro for mortgaging his land in the country. Fallace, impatient with her workaday husband, admires Brisk’s courtliness and dreams of becoming a court lady.

Buffone, accompanied by Puntarvolo, tries to find two retainers for his newly arrived gentleman, Sogliardo. Puntarvolo, who has with him a dog and a cat, explains that his wife withdrew from the Constantinople venture and that the cat will go in her place.

Brisk promises to take the hopeful Macilente to court if Macilente will purchase himself a fitting suit of clothes. Actually, it is Macilente’s purpose to discover Brisk’s true standing at the court. Fungoso and his tailor, ever in pursuit of the latest fashion, studies Brisk’s clothes as the knight talks to his companions. Sogliardo, who desires to have every gentlemanly attainment, retains a braggart down-at-heels rascal, Shift.

The good weather that prevails in the country becomes the despair of Sordido. In desperation, he attempts to hang himself, but he is rescued from that folly by the neighboring farmers, who will save him despite his despicable miserliness. The revelation to him of his evil nature causes him to have a change of heart; he vows to be a kind and generous neighbor henceforward.

Dressing themselves in new clothes, Brisk and Macilente appear at the court, Macilente to observe court life and Brisk’s deportment. Macilente marvels at the inane discourse between Brisk and Saviolina, a court lady, and he is amused when Saviolina puts Brisk out of countenance for his abominable habit of smoking.

Fallace, meanwhile, dreams of the virtues of courtier Fastidious Brisk and pays no attention to Deliro’s efforts to please her. When Macilente tells them of Brisk’s folly at court, Deliro is determined to foreclose on the knight. Fallace, shocked at Macilente’s disloyalty and eager to help Brisk, sends Fungoso, whom she gives money to buy himself a new suit, to warn Brisk of her husband’s intentions.

Brisk fails to keep an appointment at the notary’s, where he is to contribute a hundred pounds to Puntarvolo’s venture. Not finding Brisk immediately, Deliro has time to reconsider his plan. He decides not to foreclose on Brisk and he renounces Macilente’s friendship because Macilente, he feels, unreasonably urged him to be more realistic in his attitude toward his wife. Sogliardo, meanwhile, is delighted with his man Shift, who pretends to be a former highwayman, but who is, in reality, a shiftless, cowardly indigent. Brisk makes his belated appearance at the notary’s, with the explanation that he was detained by ladies of the court. Fungoso, gone to see his tailor, fails in his mission to intercept Brisk.

Puntarvolo prepares for his journey to Constantinople with his dog and cat. Sogliardo, persuaded by Buffone and Brisk that the time finally comes, decides to become a courtier. All of his acquaintances conspire to make a fool of him. Fungoso, dressed in what he thinks is the latest fashion, discovers Brisk to be wearing a new suit and is unhappy.

At the palace foolish old Puntarvolo puts his dog in the care of a surly groom. Macilente privately obtains the dog from the groom and poisons it. Brisk and Puntarvolo tell Saviolina that they are presenting to her an incomparable courtier, Sogliardo, and that this courtier enjoys playing the part of a country boor. Confronted by clownish Sogliardo, Saviolina insists that she can detect the gentleman in him; she is appalled to discover that Sogliardo, who is not aware of the joke, is a rude peasant. When Puntarvolo misses his dog, he accuses Shift of doing away with the animal and threatens to beat the man. Shift, frightened, confesses, to the disenchantment of Sogliardo, that he never had the courage to commit even one of the crimes of which he boasted.

At the Mitre Tavern, Buffone, who cannot endure the follies and affectations of court life, greets his companions. Puntarvolo, dejected by the loss of his dog and the loss of his wager, is teased by Buffone. In a rage, Puntarvolo seals Buffone’s lips with sealing wax. When the police arrive, everyone tries to flee. Brisk is seized. Fungoso, hiding under a table, is discovered and held to pay the reckoning for all the company ate and drank.

Macilente, seeing in the situation a chance to rid Deliro and Fallace of their humors, sends Deliro to rescue Fungoso at the tavern and Fallace to the jail to comfort Brisk. Deliro pays the bill at the Mitre Tavern. Fungoso declares that he is through with fashion forever. Macilente then sends Deliro to the jail to obtain Brisk’s release, after telling him that by so doing Deliro will be reconciled to his wife. At the jail Deliro, seeing Fallace’s interest in Brisk, is suddenly awakened from his misperceptions. Brisk is doomed to serve a term for his debts. Thus the air is cleared and all who were taken with a folly are cured.