The merest accident of microgeography had meant that the first man to hear the voice of Om, and who gave Om his view of humans, was a shepherd and not a goatherd. They have quite different ways of looking at the world, and the whole of history might have been different. For sheep are stupid, and have to be driven. But goats are intelligent, and need to be led.

Books bend space and time. One reason the owners of those aforesaid little rambling, poky secondhand bookshops always seem slightly unearthly is that many of them really are, having strayed into this world after taking a wrong turning in their own bookshops in worlds where it is considered commendable business practice to wear carpet slippers all the time and open your shop only when you feel like it.

Witches were a bit like cats. They didn’t much like one another’s company, but they did like to know where all the other witches were, just in case they needed them.

I get it,' said the prisoner. 'Good Cop, Bad Cop, eh?' If you like.' said Vimes. 'But we're a bit short staffed here, so if I give you a cigarette would you mind kicking yourself in the teeth?

My experience in Amsterdam is that cyclists ride where the hell they like and aim in a state of rage at all pedestrians while ringing their bell loudly, the concept of avoiding people being foreign to them.

They were small, brightly coloured, happy little creatures who secreted some of the nastiest toxins in the world, which is why the job of looking after the large vivarium where they happily passed their days was given to first-year students, on the basis that if they got things wrong there wouldn't be too much education wasted.

For the first time in her life Granny wondered whether there might be something important in all these books people were setting store by these days, although she was opposed to books on strict moral grounds, since she had heard that many of them were written by dead people and therefore it stood to reason reading them would be as bad as necromancy. Among the many things in the infinitely varied universe with which Granny did not hold was talking to dead people, who by all accounts had enough troubles of their own.