The Queen of the Elves (see Lords and Ladies) has another attempt at invading the Discworld, by stealing children and infesting dreams.  With the help of the Wee Free Men, the Nac Mac Feegle (see Carpe Jugulum), 9-year-old Tiffany Aching finds out that her grandmother used to be the witch of the Chalklands, and that she has inherited the trade. So when her baby brother is stolen, Tiffany and the Nac Mac Feegle enter the elves' world to steal him back.

There's trouble on the Aching farm – a monster in the river, a headless horseman in the driveway and nightmares spreading down from the hills. And now Tiffany Aching's little brother has been stolen by the Queen of the Fairies (although Tiffany doesn't think this is entirely a bad thing). Tiffany's got to get him back. To help her, she has a weapon (a frying pan), her granny's magic book (well, Diseases of the Sheep, actually) and— 'Crivens! Whut aboot us ye daftie!' —oh yes. She's also got the Nac Mac Feegle, the Wee Free Men, the fightin', thievin', tiny blue-skinned pictsies who were thrown out of Fairyland for being Drunk and Disorderly... A wise, witty and wonderfully inventive adventure set on the Discworld.