Off the coast of the country of Illyria, a storm has caused a terrible
 shipwreck. A young woman named Viola is swept onto the Illyrian shore.
 Finding herself alone in a strange land, she assumes that her twin brother,
 Sebastian, has been drowned in the wreck, and tries to figure out what sort
 of work she can do. A friendly sea captain tells her about a local nobleman,
 Count Orsino, who is currently courting a beautiful but reluctant
 noblewoman, Lady Olivia. Since Lady Olivia refuses to talk with any
 strangers, Viola can't look for work with her. But she decides to disguise
 herself as a man, taking on the name of "Cesario," and goes to work in the
 household of Count Orsino.

       Viola/"Cesario" quickly becomes a favorite of Orsino, and he makes
 "Cesario" his page. Viola/"Cesario" finds herself falling in love with
 Orsino--a difficult love to pursue, as Orsino believes her to be a man. But
 when Orsino sends "Cesario" to deliver Orsino's love messages to the
 disdainful Olivia, Olivia herself falls for the beautiful young "man." Now
 Viola/"Cesario" is caught between a rock and a hard place. Viola/"Cesario"
 loves Orsino, Orsino loves Olivia, and Olivia loves Viola/"Cesario"--and
 everyone is miserable.

       Meanwhile, we meet the other members of Olivia's household: her
 rowdy uncle, Sir Toby; his foolish friend, Sir Andrew Aguecheek, who is
 trying in his hopeless way to court Olivia; Olivia's witty serving-woman,
 Maria; Feste, the clever clown of the house; and the dour, prudish steward
 of Olivia's household, Malvolio. When Sir Toby and the others take offense
 at Malvolio's constant efforts to spoil their fun, Maria engineers a practical
 joke to make Malvolio think that Olivia is in love with him. They also trick
 him into behaving so strangely that Olivia thinks he has gone insane,
 allowing the gleeful Maria, Toby and the rest to lock Malvolio into a small,
 dark room for his "treatment" and torment him at their will.

       Sebastian, who is still alive after all but believes his sister Viola to be
 dead, arrives in Illyria, along with his friend and protector Antonio. When
 Sebastian coincidentally approaches Olivia's grounds, cases of mistaken
 identity begin to pile up, and nearly everybody winds up getting into a fight
 or thinking that someone has betrayed him or her. In the midst of all this,
 Olivia, encountering Sebastian and thinking he is "Cesario," asks him to
 marry her and, to her great joy, finds him willing at last.

       Eventually, Viola and Sebastian wind up in the same place at the
 same time, and all is revealed. Orsino realizes that he loves Viola/"Cesario,"
 now that he knows she is a woman, and asks her to marry him. We
 discover that Sir Toby and Maria have also been married somewhere
 private. Finally, someone remembers Malvolio, and lets him out of the dark
 room. The trick is revealed in full, and the embittered Malvolio storms off,
 leaving the happy couples to their celebration.