Duke Orsino is experiencing lovesickness because he is rejected by Olivia who has sworn off men for 7 years due to her brother’s death. Viola survives a shipwreck and thinks her twin brother, Sebastian, is dead. With the Captain’s help, Viola disguises herself as a man (Cesario) and tries to get a job at the Duke’s court. Sir Toby and Sir Andrew arrive at Olivia’s home drunk. Maria scolds them for their behavior. Disguised as Cesario, Viola, who has quickly become Orsino’s confident, goes to Olivia’s court in an attempt to win Olivia’s love for the Duke. Olivia falls in love with Cesario and sends Malvolio with a ring so that Cesario will have to return to her court. After Antonio rescues Sebastian, the two travel into Illyria. They assume Viola is dead. Sebastian seeks the court of Orsino, who has banned Antonio. Malvolio disciplines Sir Toby, Sir Andrew, Fabian and Maria for their late night rowdiness. Maria plans to seek revenge on Malvolio for his actions by writing a fake love letter from Olivia. Cesario (Viola) confesses his love for Orsino in puzzling terms that the Duke misunderstands. Malvolio finds the fake love letter from Olivia. It asks that he wear yellow stockings and crossgarters, be rude to authority figures, and smile at her incessantly. Malvolio vows to follow all of these instructions the next time her sees Olivia. Sir Andrew is upset the Olivia is in love with Cesario. Sir Toby convinces him that she is only pretending to be in love with Cesario to make him jealous and that he should challenge Cesario to a duel to prove his love for Olivia. Antonio gives Sebastian some money while Sebastian goes to the Duke’s court and Antonio makes arrangements for their food and lodging. Malvolio encounters Olivia and follows all of the instructions of his fake love letter. This makes Olivia think Malvolio has gone crazy. As a result, Maria, Sir Toby and Fabian put Malvolio in a dark room with a straight jacket on so that they can continue their plot of revenge against him. Sir Toby and Fabian set up a duel between Cesario and Sir Andrew, who do not want to fight one another. Antonio defends who he thinks is Sebastian but is really Cesario. Because he has revealed his presence in Illyria he is arrested. Sir Andrew attacks Sebastian but Olivia arrives and breaks up the fight. Feste disguises himself as Sir Topas and tries to make Malvolio believe he is going insane. Olivia offers to marry Sebastian who agrees.