The Discworld is very much like our own - if our own were to consist of a flat planet balanced on the back of four elephants which stand on the back of a giant turtle, that is . . . 'Destiny is important, see, but people go wrong when they think it controls them. It's the other way around.' Three witches - Granny Weatherwax, Nanny Ogg and Magrat Garlick - have gathered on a lonely heath. A king has been cruelly murdered, his throne usurped by his ambitious cousin. An infant heir and the crown of the kingdom, both missing . . . Witches don't have these kind of dynastic problems themselves - in fact, they don't have leaders. Granny Weatherwax was the most highly-regarded of the leaders the witches don't have. But even she found that meddling in royal politics was a lot more complicated than certain playwrights would have you believe . . . The Discworld novels can be read in any order but Wyrd Sisters is the second book in the Witches series.