In Volpone’s house, Mosca is dressed like an aristocrat while Volpone has assumed the disguise of a commandadore. They each make sure that the disguises are convincing. Aside, Mosca says that if he remains in disguise as an aristocrat, he might become one. Volpone leaves to find out what’s happening at the court.
By dressing like an aristocrat, Mosca challenges the social order, drawing a parallel to the playwright himself who fought hard to climb social rankings. Much like Jonson disparages the power of language in this play, his comparison of Mosca’s disguise to his own rise in social status seems to effectively undercut Jonson’s legitimacy in his professional and social lives.
Alone in Volpone’s home, Mosca says that the “fox is out of his hole,” and he plans to make Volpone pay for the new ruse, unless Volpone is willing to make a deal. He then calls Androgyno, Castrone, and Nano, and tells them to go outside. Alone again, Mosca outlines a plan to get some of Volpone’s money. Since Volpone is pretending to be dead and Mosca is named heir, Mosca says he’ll force Volpone to stay fake-dead until he agrees to share some of his fortune. Mosca says that no one would call it a sin to cheat Volpone, and that Volpone’s tricks will pay for themselves. He calls his plan “the Fox Trap.”
Mosca here is taken by his own desire, possibly for money, possibly for increased social status, possibly for both, since they go hand in hand. Ironically, he justifies his plan to steal Volpone’s wealth by disparaging Volpone’s own trickery. Playing on Volpone’s name, Mosca gives his plan the name “Fox trap” (almost as if it were a play, not a scheme). It’s reminiscent of Hamlet’s plan to trap his uncle with a play called “the Mouse Trap.”