"Don't you know a Sand-fairy when you see one?"
It looked so grieved and hurt that Jane hastened to say, "Of course I see you are, now. It's quite plain now one comes to look at you."
"You came to look at me, several sentences ago," Five Children and It
One day Robert, Anthea, Jane, Cyril, and Lamb find a rather grouchy sand fairy called a Psammead. It says that they can get five wishes from it, but each wish will all turn to stone at sunset. As everyone knows, wishes aren't as easy as they look, and what with accidental wishes, unforeseen consequences, and good old-fashioned bad luck, the children soon find themselves having the time of their lives.