When Cyril, Anthea, Robert, Jane and their baby brother go digging in the gravel pit, the last thing they expect to find is a Psammead – an ancient Sand-fairy! Having a Sand-fairy for a pet means having one wish granted each day. But the children don't realize all the trouble wishes can cause . .

The five children find a cantankerous sand fairy, a psammead, in a gravel pit. Every day 'It' will grant each of them a wish that lasts until sunset, often with disastrous consequences.