Information for Twelfth Night at Royal Shakespeare Theatre, Stratford-Upon-Avon (Play). Or What You Will. Shakespeare comedy of mistaken identity, practical jokes and unrequited love. Rescued from a shipwreck the twins Viola and Sebastian arrive independently in Illyria, both thinking the other is drowned. Viola disguises herself as a boy and finds employment with the Duke who is in love with Olivia. Malvolio is the subject of a cruel joke played on him by Sir Toby Belch (yellow stockings cross-gartered) leading him to believe that Olivia loves him. But Olivia has fallen in love with the disguised Viola, while she is in love with the Duke (following it so far?!).