Why now? thought Death.

He recognized them. They were not life forms. They were… nonlife-forms. They were the observers of the operation of the universe, its clerks, its auditors. They saw to it that things spun and rocks fell.

And they believed that for a thing to exist it had to have a position in time and space. Humanity had arrived as a nasty shock. Humanity practically was things that didn't have a position in time and space, such as imagination, pity, hope, history and belief. Take those away and all you had was an ape that fell out of trees a lot.

Intelligent life was, therefore, an anomaly. It made the filing untidy. The Auditors hated things like that. Periodically, they tried to tidy things up a little.

The year before, astronomers across the Discworld had been puzzled to see the stars wheel gently across the sky as the world-turtle executed a roll. The thickness of the world never allowed them to see why, but Great A'Tuin's ancient head had snaked out and down and had snapped right out of the sky the speeding asteroid that would, had it hit, have meant that no one would have needed to buy a diary ever again.

No, the world could take care of obvious threats like that. So now the grey robes preferred more subtle, cowardly skirmishes in their endless desire for a universe where nothing happened that was not completely predictable.

The butter-side-down effect was only a trivial but telling indicator. It showed an increase in activity. Give up, was their eternal message. Go back to being blobs in the ocean. Blobs are easy.

But the great game went on at many levels, Death knew. And often it was hard to know who was playing.

EVERY CAUSE HAS ITS EFFECT, he said aloud. SO EVERY EFFECT HAS ITS CAUSE.

He nodded at the Death of Rats. SHOW ME, said Death. SHOW ME… A BEGINNING.

Tick

It was a bitter winter's night. The man hammered on the back door, sending snow sliding off the roof.