This story takes place in Illyria, Italy. Viola and her twin brother, Sebastian are shipwrecked during a terrible storm and both believe their twin died in the storm. At the beginning of the play Viola is afraid to live alone in the world as a woman so she decides to disguise herself as a young man. She calls herself Cesario. Viola goes to the Duke of Illyria, Orsino, to look for work as a musician. She soon finds out that Orsino is sick with love for Lady Olivia. Olivia will not return his love. Viola offers to visit Olivia and woo her for the Duke. Orsino happily agrees to Viola’s plan.

Lady Olivia is very difficult to meet in person. Many men are trying to win her hand in marriage but none have been successful. Olivia’s brother just died and she is in mourning. She refuses to see anyone. Viola is lucky, however, because Olivia is curious to meet the pretty young boy at her gate. Olivia lets Viola in and soon falls in love with her because she thinks Viola is a young man named Cesario. Viola doesn’t know what to do. She cannot tell anyone that she is really a woman! 

While Olivia is falling in love with Viola (Cesario), there is a bit of mischief going on among the people of her estate. Her uncle, Sir Toby Belch, is always drinking wine and causing trouble. Sir Toby, his friend Sir Andrew, and the fool Feste, come home late one evening, and are scolded by Malvolio, one of Olivia’s servants, for being so loud and disrespectful. Malvolio isn’t very nice to anyone and doesn’t have a sense of humor. Sir Toby, Feste, Sir Andrew, and Olivia’s serving woman Maria decide to play a cruel trick on him. They will make Malvolio believe Olivia loves him. Olivia will think he’s gone mad.