The final would-be heir now appears. He is a merchant named Corvino, and his names mean "crow" in Italian. He brings a pearl as his gift; Mosca then lets him know that Volpone has been saying his name constantly, though he is so ill he can barely recognize anyone and is unable to say anything else. Corvino hands over the pearl, and Mosca then informs him he took it upon himself to write up a will, interpreting Volpone's cries of "Corvino" as indicating the Fox's desire to have Corvino be his heir. Corvino hugs and thanks Mosca for his help, then asks whether or not Volpone saw them celebrating. Mosca assures him Volpone is blind. Corvino is worried that the sick man might hear them talking this way, but Mosca assures him he is dead by hurling abuse in his ear; he then asks Corvino to join in, which the merchant does gladly. But when Mosca suggests that Corvino suffocate Volpone, Corvino backs off and begs Mosca not to use violence. Corvino then leaves, and pledges to share everything with Mosca when he inherits Volpone's fortune, but Mosca notes that one thing Corvino will not share: his wife. When Corvino is gone, another caller arrives: it is Lady Politic Would-be, the wife of the English knight Sir Politic Would-be, but Volpone does not want to talk-or do anything else-with her, so she is not let in. Mosca explains that Lady Politic's reputation for promiscuity is overblown, unlike Corvino's wife, she is not beautiful enough to be promiscuous. According to Mosca, Corvino's wife is perhaps the most beautiful woman in all of Italy. Volpone is inflamed by Mosca's description, and vows to see her. Mosca explains that she is never let out of the house by the insanely jealous Corvino, and is kept guarded by ten spies. Volpone nevertheless is resolved to see her, so he decides to go in disguise-but not too well disguised, since this might be his first introduction to the beautiful Celia.
The final scene is in many ways a conclusion of the scenes with Voltore and Corbaccio. Corvino is not particularly different from the first two characters in terms of his intentions in the scene, or in the way he is thoroughly gulled by Volpone and Mosca. Volpone "What a rare punishment / Is avarice to itself," thus noting the poetic justice of their act, the way it is a perfect retribution for the prospective heirs. Though that last quotation can also be considered an instance of foreshadowing. Volpone will be punished himself in Act V, also as a result of his own greed; as Jonson wishes to convey an unambiguous moral message in the play, in the end all greed will be punished, even that of the likeable Volpone. A couple of other developments combine to presage future plot developments in the play. First, there is Mosca's suggestion that Corvino kill Volpone. It is out of keeping with what Mosca has said before in terms of its violence; and though it is taken as a joke by Volpone, it does raise some doubts about Mosca's loyalty (what if Corvino had gone ahead with the act), and also serves to initially associate Corvino with violence-an association that will be strengthened in the following acts. This scene also introduces Corvino's, who will be Volpone's love interest in the play. The love interest gives the plot added impetus; if the play focused entirely around Volpone's con-game, it would in the end prove tiresome; but we instead end the Act with a determined Volpone vowing to introduce himself to a beautiful woman, a source of suspense (especially to anyone with a romantic streak). Taken on one level, the main plot of Volpone is a fable; each character are each personifications of different animals, in a story that has a direct moral message. "Volpone" means "Fox" in Italian, and "Mosca" means "Fly". In many of Jonson's plays, a name gives a strong indication as to the nature of a character, and this play is no different; Volpone is the "cunning" Fox, who appears wounded; "Mosca" is the parasitical, insect-like creature, circling around the Fox, and occasionally feeding off of him (gold, in this metaphor, takes the place of Volpone's flesh). Voltore, Corbaccio and Corvino act like the carrion birds they are named after (the vulture, the crow and the raven, respectively), by circling around the Fox and waiting for him to die. But the Fox is craftily faking his wounds, and the Fly helps him, and the birds end up losing their feathers (their wealth). This simple fable helps clearly enunciate the meaning of the play and it also suggests that the main characters in the play are somewhat "beastly"; they are acting out animal instincts, and not listening to the voice of conscience and reason; in short, they are not fully human.