From the introduction: Look. Pay attention. This is space - the empty thing between the worlds, if you remember. Large, black and scattered with tiny white flecks, like dandruff sprinkled liberally over the shoulders of an enormous dinner jacket. A lifeless vacuum, empty in theory of anything approaching motion or activity - through which, to the utter gibbering confusion of any life form arrogant enough to consider itself sentient, a reptile the size of a gas-giant crawls, Great A'Tuin the star turtle, bearing on its back the destiny of millions. By one of the more far-fetched whims of destiny, A'Tuin supports on its gigantic shell four rather less enormous elephants, who in turn shoulder the massive saucer-shaped conglomeration of rock, water and organic matter known as the Discworld - the most unconventionally designed planet in the chaotic mess often laughingly referred to as creation.