Lords and Ladies (Discworld)

Ever wonder what those magic circles of stones in the English countryside are for? They're to keep the elves out. Elves are nasty (besides being brutish and short). They're vicious. They love cruelty. Plus, to make things worse, elves have got It. Glamour. Style. Humans find elves absolutely irresistible. They actually think elves are cute! So when an infestation of Faerie Trash invades the Kingdom of Lancre, upsetting the Royal Wedding Plans (not to mention the Annual Morris Dance), the ordinary people of Lancre are helpless. It's up to the witches, led by Granny Weatherwax, to deal with the vicious little bastards. Which is all right with Granny. She thinks elves are cute, too. And that makes them even more fun to kill.