Discworld is a world and a mirror of worlds.

This is not a book about Australia. No, it's about somewhere entirley different which just happens to be, here and there, a bit... Australian.

Still... no worries, right?

Against the stars a turtle passes, carrying four elephants on its shell.

Both turtle and elephants are bigger than people might expect, but out between the stars the difference between huge and tiny is, comparatively speaking, very small.

But this turtle and these elephants are, by turtle and elephant standards, big. They carry the Discworld, with its vast lands, cloudscapes, and oceans.

People don't live on the Disc any more than, in less hand-crafted parts of the multiverse, they live on balls. Oh, planets may be the place where their body eats its tea, but they live elsewhere, in worlds of their own which orbit very handily around the centre of their heads.

When gods get together they tell the story of one particular planet whose inhabitants watched, with mild interest, huge continent-wrecking slabs of ice slap into another world which was, in astronomical terms, right next door – and then did nothing about it because that sort of thing only happens in Outer Space. An intelligent species would at least have found someone to complain to. Anyway, no one seriously believes in that story, because a race quite that stupid would never even have discovered slood.

People believe in all sorts of other things, though. For example, there are some people who have a legend that the whole universe is carried in a leather bag by an old man.

They're right, too.

Other people say: hold on, if he's carrying the entire universe in a sack, right, that means he's carrying himself and the sack inside the sack, because the universe contains everything. Including him. And the sack, of course. Which contains him and the sack already. As it were.