Miss Perspicacia Tick is a full-time witch with a Gold Swimming Certificate from the Quirm College for Young Ladies. As the book opens, she has just discovered a ripple in the walls of the world - this, she suspects,is being caused by another world making contact. The point of contact appears to be in an area called the Chalk - she thinks she should go and investigate, but her elbow (which is rarely wrong) tells her there is already a witch living there.
Tiffany Aching, the book's heroine, is nine years old and lives on a farm in the Chalk. She has six older sisters, one younger brother (the permanently sticky Wentworth) and is very good with cheese. Throughout the book, it's clear she idolised her Granny Aching, who died when Tiffany was seven. Granny was a shepherdess, an expert on sheep, very fond of Jolly Sailor tobacco and - Tiffany suspects - a witch. Remembering how Granny always said it was important to speak up for those who have no voice, Tiffany has decided she wants to be a witch as well.
As it turns out, Tiffany is the witch Miss Tick's elbow sensed and has the gifts of First Sight and Second Thoughts. Miss Tick is also correct about two worlds colliding - Fairyland, ruled by the Queen, is running into the Discworld. Fairyland is where dreams come true, which isn't quite as pleasant as you might think - nightmares, after all, also count as dreams. Worse yet, after having "rescued" Wentworth from Jenny Green-Teeth, thanks to an expertly delivered frying-pan to the face, Wentworth is kidnapped by the Queen. Tiffany feels it's up to herto rescue him and bring him home.
The stars of the book, however, are the Wee Free Men. Also known as the Nac Mac Feegle, they were thrown out of Fairyland for being drunk, disorderly and rebelloius. A Pictsie race, they are covered in tattoos, have blue skin and red hair and wear little other than kilts and swords. Extremely strong and fast, they enjoy stealing, fighting and drinking - Granny Aching's Special Sheep Linament is a particular favourite. They don't like telling anyone their names, think writing is magical and are frightened only of lawyers. Luckily for Tiffany, they join her raid on Fairyland. Rob Anybody Feegle, the Big Man O' The Clan, is especially brave, while Not-as-big-as-Medium-Sized-Jock-but-bigger-than-Wee-Jock-Jock is notable for his willingness to use poetry in tight situations. The Toad (Miss Tick's familiar) - who is reasonably sure he was once human - also offers Tiffany a great deal of advice on her travels. His current condition is the result of having crossed a Fairy Godmother.
"The Wee Free Men", a "Story of Discworld" rather than a "Discworld Novel", won the Locus Award for Best Young Adult Novel in 2004. If you've enjoyed anything from the ordinary Discworld series, you'll certainly enjoy this !