In a distant...and second hand set of dimensions,through wavering star mists, see..the Great A'Tuin.Drifting onwards through space,atop the shell of the great turtle,are four giant elephants,upon whose broad shoulders rests...the Discworld.For the people on the Disc,the turtle was a mere hypothesis,until one day, the island kingdom of Krull,whose rim-most mountains project over the rim fall, lowered over the edge a brass vessel containing several astrozoologists.