Feste and Sebastian are in front of Olivia’s house. Feste thinks of him as Cesario (Viola) to which Sebastian behaves strangely. Sir Andrew enters and thinking of him as Cesario starts beating. Sebastian hits him back.
They recognize him as Cesario because of his similarity to his twin Viola. When they’re fighting, Olivia enters and stops them. She also addresses Sebastian as Cesario and it confuses him further. She asks him to calm down and come with her.
Maria and Feste are planning the further torture of Malvolio by introducing Feste as Sir Topas the curate who has come to meet Malvolio the lunatic. Malvolio pleads to Feste about their revenge against him while thinking of him as Sir Topas.
Feste while acting as Sir Topas condemns Malvolio to darkness further. All of them conspire together to make Malvolio more hysteric. Feste keeps frustrating him further by asking him again and again whether he is mad or not.
Malvolio pleads him to provide him with pen and paper so that he can prove that he is not mad but nobody pays him attention to punish him more.
Sebastian is in the garden of Olivia. He is doubtfully wondering about this sudden revelation of offerings. He thinks of the whole estate which Olivia has and it enchants him. He is doubtful nevertheless of this whole affair. Olivia enters with a priest and asks Sebastian to assure her of their future.