Witches Abroad (Discworld book 12), Terry Pratchett

You can't go around building a better world for people. Only people can build a better world for people.

Otherwise, it's just a cage.'There's power in stories. The Fairy Godmother is good. The servant girl marries the Prince.

Everyone lives happily ever after . . .

don't they?The witches Granny Weatherwax, Nanny Ogg and Magrat Garlick are travelling to far-distant Genua to stop a wedding and save a kingdom. But how do you fight a happy-ever-after, especially when it comes with glass slippers and a power-hungry Fairy Godmother who has made Destiny an offer it can't refuse?It's hard to resist a good story, even when the fate of the kingdom depends on it . .

. Witches Abroad is the third book in the Witches series, but you can read the Discworld novels in any order.