Light Fantastic, The (Discworld Novel 2)

The Discworld is very much like our own – if our own were to consist of a flat planet balanced on the back of four elephants which stand on the back of a giant turtle, that is . .

'What shall we do?' said Twoflower.
'Panic?' said Rincewind hopefully. He always held that panic was the best means of survival.

As it moves towards a seemingly inevitable collision with a malevolent red star, the Discworld could do with a hero.

What it doesn’t need is a singularly inept and cowardly wizard, still recovering from the trauma of falling off the edge of the world, or a well-meaning tourist and his luggage which has a mind (and legs) of its own.

Which is a shame, because that's all there is . . .