After surviving a shipwreck off the coast of Illyria, Viola disguises herself as a boy to get a position at the court of Duke Orsino, who is in love with beautiful Olivia. Unknown to Viola, her twin brother Sebastian has also survived the shipwreck. When he too arrives in Illyria, confusion and misunderstandings follow. After many cases of mistaken identity, who will be lucky in love? The lovesick Duke, mournful Olivia or practical Viola?