Sofia and Florville are in love, but her guardian, Gaudenzio, opposes the match. Florville's father and Gaudenzio are old enemies. Florville's father dies, removing one barrier, but Gaudenzio has already agreed to wed Sofia to the son of his old friend, Signor Bruschino. Sofia has never met her fiancée, as they were betrothed by correspondence. On his way to meet Sofia, young Bruschino stops at a tavern, runs up an impressive bill and is detained when he is unable to pay. Seizing the opportunity, Florville pretends to be Bruschino junior so that he can marry Sofia. Complications arise when Bruschino senior arrives at Gaudenzio's house. Fortunately, however, he is eventually forced to accept Florville as his own son. In a playful trio, Florville (as Bruschino junior) begs his "father" for forgiveness, while Gaudenzio upbraids old Bruschino for his lack of fatherly sympathy.