'People didn't seem to be able to remember what it was like with the elves around. Life was certainly more interesting then, but usually because it was shorter. And it was more colourful, if you liked the colour of blood . . .'

On Midsummer Night, dreams are especially powerful. So powerful, in fact, that they can cause the walls between realities to come crashing down. And some things you really don't want to break through.

The witches Granny Weatherwax, Nanny Ogg and Magrat ...