Upon encountering Sebastian, Feste, who was seeking Cesario, tries in vain to convince Sebastian that he is sought by Olivia. Annoyed, Sebastian pays Feste to leave him alone when Sir Andrew appears on the scene and strikes Sebastian. Sebastian reciprocates the blow manifold only to be restrained by Sir Toby. Feste runs to go get Olivia. Sebastian frees himself and draws his sword, prompting Sir Toby to draw his when Olivia appears to rebuke and dismiss Sir Toby and his friends. Olivia apologizes on behalf of her uncle and begs Sebastian to let her attend to him. In disbelief, Sebastian concedes to Olivia’s wishes.
Just a moment ago, Sebastian had cursed Illyria for harboring madmen, and now he can’t help but to think he is in dream from which he would prefer not to awake.
Maria and Sir Toby contrive to have Feste impersonate Sir Topas, a priest/exorcist, who proceeds to attend to Malvolio’s madness. Malvolio, who is bound and sequestered, pleads Sir Topas to report his predicament to Olivia. Malvolio pleads that he is falsely restrained, that he is not mad, and that he is being cruelly kept imprisoned in the dark. Feste rebuts every plea with a dismissive witticism and leaves. Upon consulting with Sir Toby, he is told to go back and speak with Malvolio (as Feste himself this time), with the hope of finding a way to have the prank blow over without any of it getting out to Olivia. (On account of engaging Sebastian at sword point, Sir Toby is already in Olivia’s bad graces and would like to keep the situation from getting any worse.) By and by, Feste engages Malvolio who pleads the jester to be his advocate. After much pleading on Malvolio’s part, Feste agrees to be Malvolio’s advocate: Feste will get Malvolio some light, ink, and paper with which Malvolio will appeal to Olivia in writing.
Sebastian grapples with himself. His senses tell him that what is happening is real; his reason tells him that to believe in his senses is madness. Anon, Olivia appears with a priest. She proposes that she and Sebastian get married this instant, assuming of course that Sebastian has no objections, that he will pledge to love and honor her. Sebastian has no objections. He assures her that he will give his pledge to love and honor her.