The Light Fantastic

Terry Pratchett's profoundly irreverent novels are consistent number one bestsellers in England, where they have garnered him a revered position in the halls of parody next to Mark Twain, Kurt Vonnegut, Douglas Adams, and Carl Hiaasen.
In The Light Fantastic only one individual can save the world from a disastrous collision. Unfortunately, the hero happens to be the singularly inept wizard Rincewind, who was last seen falling off the edge of the world...