The story begins when a group of children move from London to the countryside of Kent. While playing in a gravel pit the five children – Robert, Anthea, Cyril, Jane and their baby brother, known as the Lamb – uncover a rather grumpy, ugly and occasionally malevolent Psammead or sand-fairy, who has the ability to grant wishes. He persuades the children to take one wish each day to be shared among them, with the caveat that the wishes will turn to stone at sunset. This, apparently, used to be the rule in the Stone Age, when all children wished for was food, the bones of which then became fossils. However, when the five children's first wish, to be "as beautiful as the day", ends at sunset, its effects simply vanish, leading the Psammead to observe that some wishes are too fanciful to be changed to stone.