In the 400 years since The Tempest was first staged, millions of words have been written about it. Critics, directors and actors have interpreted it in widely different ways and developed theories ranging from the more-or-less plausible to the eccentric and the completely outlandish. It is undoubtedly one of Shakespeare's greatest plays, and as well as its bewitching music, its hallucinatory quality and its enchanted island setting, it contains some...