from the back cover:
When the children dug a hole in the gravel-pit, they were very surprised at what they found. 'It' was a Psammead, a sand-fairy, thousands of years old.
It was a strange little thing - fat and furry, and with eyes on long stalks. It was often very cross and unfriendly, but it could give wishes - one wish a day. 'How wonderful!' the children said.
But wishes are difficult things. They can get you into trouble . . .