Orsino loves Olivia (unrequitedly). Twins, Viola and Sebastian, are shipwrecked. Viola cross-dresses, works for Orsino, and Olivia falls in love with her/him. Olivia's household trick Malvolio into thinking Olivia loves him. Olivia (confused) marries Sebastian. The twins reunite, Malvolio's gulling and Viola's gender are revealed, and Orsino proposes to Viola.