In the land of Illyria, Duke Orsino pines away for the beautiful Countess Olivia, who does not return his love. On the Illyrian coast, a shipwrecked Viola fears her twin brother, Sebastian, has drowned. Alone in a strange land, Viola disguises herself as a young man whom she calls “Cesario,” and seeks employment with the Duke Orsino.
At Countess Olivia’s house, Sir Toby Belch, Olivia’s uncle, encourages his wealthy friend Sir Andrew Aguecheeck to woo Olivia. But Sir Andrew is discouraged by Olivia’s coldness and plans to leave the next morning—until Sir Toby, looking to benefit further from Sir Andrew’s wealth, flatters him into staying.
Meanwhile, at Duke Orsino’s house, “Cesario” has already become a favorite of Orsino, trusted even to persuade Olivia to marry the Duke. Cesario reluctantly agrees to carry his message—because, as she reveals when she is alone, Viola herself has fallen in love with Orsino and wishes that she could be his wife.
Viola, as Cesario, delivers Orsino’s message and charms Olivia with “his” speech. After sending Cesario back to the Duke with another refusal, Olivia finds to her own surprise that she has fallen passionately in love with young Cesario.
Sebastian, Viola’s twin brother, has survived the shipwreck, rescued by Antonio. Like Viola, Sebastian believes his twin is dead and resolves to visit Duke Orsino. Antonio determines to follow him even though he has enemies at Orsino’s court.
Olivia’s steward Malvolio delivers a ring to Viola (still disguised as Cesario). Viola realizes that Olivia has fallen in love with Cesario. Caught in the middle of a strange love triangle and powerless to reveal either her identity or her true desires, Viola hopes that time will untangle these problems.
Sir Toby and Sir Andrew are carousing with Olivia’s clown Feste, when Malvolio storms in and chastises them for their drunken escapades. The group mocks Malvolio, and as soon as he leaves, the assembled company plans its revenge. Maria, Olivia’s chamber maid, devises a scheme in which, with the help of some forgery, Malvolio will think Olivia is in love with him. Their plan works: Malvolio spots Maria’s forged letter lying in the garden path and believes it is from Olivia. After reading over the letter very carefully, Malvolio vows to follow its absurd instructions, leaving the conspirators to rejoice in their success.
Still disguised, Viola returns to Olivia’s house to deliver another message from Orsino. Once alone with the unhappy messenger, Olivia begs “him” not to give her any more messages from Orsino and confesses that she is deeply in love with Cesario instead. Cesario responds that he cannot love Olivia, but swears that no woman shall ever be mistress of his heart.
In the streets of Illyria, Sebastian and Antonio have at last arrived at their destination. But because Antonio is a wanted man in Illyria, he decides to stay at the inn while Sebastian roams the city.
Meanwhile, Olivia believes that Malvolio, who attempts to woo her by following the letter’s ridiculous instructions, has gone mad. Malvolio is convinced that Olivia is in love with him. When Sir Toby, Fabian and Maria come upon him, the three pretend that he is possessed by the devil and lock Malvolio up as a lunatic.
Noting Olivia’s fawning over Cesario, Sir Andrew has resolved to leave. Sir Toby and Fabian encourage him instead to challenge Cesario to a duel, in order to prove his love for Olivia. Antonio interrupts the two mutually reluctant combatants when he mistakes the disguised Viola for Sebastian – and is then himself interrupted by several Illyrian officers who recognize and arrest him as a wanted man. Antonio pleads with Viola, whom he still believes is Sebastian, to help him, but Viola has no idea who Antonio is.
Now the real Sebastian is taken for his disguised twin by an overwrought Sir Andrew. Sir Toby intervenes, and Olivia arrives just as the two are about to duel. She begs the man whom she believes to be Cesario to come into the house with her. Sebastian is bewildered, but agrees to follow her.
Inside Olivia’s house, Maria, Sir Toby, and the other servants have locked Malvolio into a small, dark chamber. Feste, disguised as Puritan clergyman Sir Topas, visits Malvolio in prison, deliberately misunderstanding the prisoner’s pleas for help. Sir Toby and Maria send Feste back, this time undisguised, to Malvolio, who swears that he is not crazy, and begs for paper, ink, and light with which to write a letter to Olivia.
Elsewhere in the house, Sebastian muses happily on the bewildering fact that he is loved by a beautiful countess. Olivia returns with a priest, asking Sebastian to marry her. Sebastian happily agrees.
Orsino calls on Olivia, accompanied by Cesario and his men. Illyrian officers enter dragging Antonio, who lashes out at Cesario, still believing him to be Sebastian, and asserts that the young man before him has been disloyal to him.
Olivia arrives, doting on Cesario and calling him husband. Orsino, angry at Cesario’s apparent betrayal of him and Olivia’s reasserted rejection, threatens to kill him. As Orsino berates Viola, Sir Andrew and Sir Toby enter injured, claiming they have just dueled with Cesario. The confused Viola claims no responsibility.
Finally, Sebastian appears, apologizing to Olivia for beating up her guests, and is seemingly confronted with his own reflection. Amazed, the twins identify one another. Orsino, realizing Olivia has married Sebastian, reminds Viola that, disguised as a boy, she often vowed her love to him. Viola reaffirms her love and Orsino declares he will marry her. Malvolio then enters—only to have his love letters from Olivia revealed to be false. Malvolio vows to revenge his unhappy ending, and hastily departs the cheerful scene. Loved at last, Orsino proclaims that the happy couples will shortly celebrate their double wedding.
– Contributed by the CST Education Department