The Colour of Magic (Discworld, #1)

In the beginning there was…a turtle.Somewhere on the frontier between thought and reality exists the Discworld, a parallel time and place which might sound and smell very much like our own, but which looks completely different. Particularly as it’s carried though space on the back of a giant turtle (sex unknown).

It plays by different rules.But then, some things are the same everywhere. The Disc’s very existence is about to be threatened by a strange new blight: the world’s first tourist, upon whose survival rests the peace and prosperity of the land.