Twelfth Night is a story of mistaken identity, love, and mischief, set in the fictional country of Illyria, which we have imagined as a luxury European coastal destination. It begins with a shipwreck, in which Viola, is separated from her twin brother, Sebastian, and washed up on the shores of Illyria. Believing her brother to be dead, Viola disguises herself as a young man, Cesario, and enters the service of Duke Orsino.
Orsino is in love with the beautiful Countess Olivia, but she refuses him, mourning her deceased brother. Orsino sends Cesario (Viola in disguise) to woo Olivia on his behalf. However, Olivia falls in love with Cesario, unaware of the true identity of her messenger. Meanwhile, Viola (as Cesario) has fallen in love with Orsino, creating a complicated love triangle. The plot becomes more complicated when the audience learns that Sebastian too was saved by Antonia, a woman wanted for sea-crimes in Illyria.
Meanwhile, Olivia’s household is filled with characters who cause their own share of drama. Maria, her head-of-household, and Malvolio, her self-important butler, are constantly at odds. Olivia's uncle, Sir Toby Belch loves a good drink as much as he loves to create havoc. His friend Sir Andrew Aguecheek competes for Olivia’s affection despite being foolish and inept. Maria, Toby, and Andrew hatch a plot to prank Malvolio, to punish him for constantly ruining their fun and talking down to them.
Throughout it all, Feste, a traveling performer, entertains, outwits, and observes all that transpires in Illyria.