A storm has caused a shipwreck and twins, Viola and Sebastian are separated thinking one another dead. Viola washes up on the shore on Illyria, and a kind sea captain helps her find work for Duke Orsino disguised as a man.
Viola (disguised as Cesario) begins work for Duke Orsino becomes his assistant, Viola finds herself falling in love with Duke Orsino, but cannot say anything as she is a ‘man’.
But when Orsino send’s Cesario to deliver Orsino’s love messages to Olivia, Olivia herself falls for Cesario, believing her to be a man.
Sir Andrew, jealous of Cesario (still Viola in disguise), challenges Cesario to a duel, but Sebastian comes onto the seen and since he looks so alike to Cesario (Viola in disguise) they mistake him for Cesario and have a duel with Sebastien instead.
Olivia goes over to Sebastian thinking that he is Cesario and asks him to marry her, he is confused, but he then sees that she is very wealthy and agrees immediately.
Antonio is getting arrested while Sebastian is with Olivia and cries out to Cesario, mistaking him for Sebastian, asking him to help him. Cesario is confused and says nothing.