After twins survive a shipwreck, neither knows that the other is alive. Viola goes into service with Count Orsino of Illyria, disguised as a young man, "Cesario." Orsino sends Cesario to woo the Lady Olivia on his behalf, but Olivia falls in love with Cesario. Viola, in the meantime, has fallen in love with Orsino. At the estate of Lady Olivia, Sir Toby Belch, Olivia’s kinsman, has brought in Sir Andrew Aguecheek to be her suitor. A confrontation between Olivia's steward, Malvolio, and the partying Toby and his cohort leads to a revenge plot against Malvolio.