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 . . .