Wyrd Sisters - Terry Pratchett

'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 . . .