For me, the Discworld is never as much fun as when I have Granny Weatherwax, Nanny Ogg, and Magrat Garlick as my chaperones, and Witches Abroad is a truly seminal work starring my three favorite witches. This is a story about stories, and on the anthropomorphic wonderland known as the Discworld stories are so powerful that they can become almost unstoppable forces; they are so important that they shape people rather than the other way around, making people do things for the sake of the stories alone. Once a story gets going, it's almost impossible to stop it. You don't tell Granny Weatherwax that anything is impossible for her to do, though, nor do you tell her you need her help, not unless you don't want her to come. The fairy godmother Desiderata knows this, although she is not particularly adept at training a successor (and since witches know when they are going to die, her death is no excuse for such lack of planning). Just before she dies, she wraps up her magic wand and sends it to Magrat Garlick, Lancre's youngest, most good-hearted, tradition-obsessed, open-minded, overlooked witch along with a note telling her appointed successor that she must go to Genua to prevent the girl Emberella from marrying the prince and that she must tell Granny Weatherwax and Nanny Ogg that they are not to come with her. Thus, all three witches are soon flying away from their homes in Lancre in route to the eastern port of Genua. Their journey finds them bumping headlong into a number of different stories, Pratchett-twisted episodes such as one involving a young girl in a red cape, her grandmother, and a wolf. It soon becomes obvious to the three witches that someone is making stories come true, but only Granny secretly knows just who is behind all this. Arriving in Genua, they are exposed to the city's own brand of magic, namely voodoo, run up against snake sisters guarding poor Emberella, delight in an entirely new kind of cooking (the ingredients of which are kept from Granny for the most part, which is obviously quite the right thing to do), and set out to stop the warped Cinderella-based fairy tale events surrounding Emberella, knowing that, should Emberella marry the prince, the other fairy godmother (they come in pairs, incidentally), the witch wielding and invigorating her power by the use of mirror magic, would have power over the whole city and force her happy endings on everyone in town. There's nothing wrong with happy endings, but being made happy against one's wishes and knowledge is one of very many things that Granny doesn't hold with. As Magrat's attempts to use the magic wand result in only pumpkins and more pumpkins, success in this unexpected tour of fairy godmothering duty requires all three witches working together, and Granny herself needs all of her skills at headology when she confronts an important figure from her past.
The ingeniously satirical incorporation of fairy tales by Pratchett makes this book worth its weight in gold, but it is the constant bickering and resulting comedy between the three very different witches that makes this book so entertaining. There is no citizen of the Discworld whom I find as fascinating and entertaining as good old Granny Weatherwax. Her obstinacy and refusal to admit a deficiency of any kind is quite comical in and of itself, but put this beside poor Magrat's idealized notions and unconventional ideas (such as her decision to wear pants and thus, to Granny's horror, let men see where her legs are underneath them) and Nanny's ribald, good-natured humor and zest for life (and alcohol and dirty songs, etc.) and you've got a recipe for high comedy indeed. Nanny's unique cat Greebo also takes on vast importance in this novel, offering us yet another unforgettable travel partner in this strange world of Pratchett's ingenious creation. Granny's character is especially well-developed in this novel, and the new-found insights into her childhood offer quite a telling new insight into her personality. Witches Abroad is among the best of the best of Pratchett's Discworld series.