The five children are Cyril, Anthea, Robert, Jane and the Lamb, their baby brother. And 'It' is the Sand-fairy known as the Psammead that lives in the gravel pits. It is furry and fat with hands like a monkey's - and, when it's in the mood, has the power to grant wishes. The children discover that wish-making is fun at first, but sometimes, when wishes come true, fun can soon turn into trouble . . .