This is the Thirtieth(!) book in Terry Pratchett's series on the Discworld--a flat world, supported on the backs of four massive elephants riding on the back of a planet-sized turtle, anything hilarious can happen here, and eventually does.
Young Tiffany Aching has lived her young life in the Chalk, where raising sheep is the normal form of living. But, when creatures out of fairy tales begin to appear, she realizes that something is very wrong. A group of tiny blue men, with bright red hair and kilts (the Nac Mac Feegle, the Wee Free Men) begin to take an interest in her, and Tiffany quickly learns that her very world is under attack by the Queen of the Elves. The Wee Free Men think that she is a witch, like her grandmother, and just maybe she will be one day, but she's not now. But, armed with her native intellect, her determination, and a wealth of memories of how her grandmother did things, Tiffany might just be enough.
This is another *great* Terry Pratchett book! I have been a fan of this author for a long time, and this book does not let you down. As is often the case in Discworld books, a couple of "regulars" put in an appearance (Granny Weatherwax and Nanny Ogg), but the show is definitely stolen by the Nac Mac Feegle - they are great! (Rob Anybody, Not-as-big-as-Medium-Sized-Jock-but-bigger-than-Wee-Jock-Jock, he he!) But, even beyond that, the story is enthralling and the characters are quite interesting. If you are a fan of humorous fantasy, then you must read this novel by the king of them all, Terry Pratchett!