Someone out there was about to find that their worst nightmare was a maddened Librarian. With a badge.

Give anyone a lever long enough and they can change the world. It's unreliable levers that are the problem.

You get all sorts of people in the library, and the librarian gets it all.

No! Please! I'll tell you whatever you want to know!" the man yelled. "Really?" said Vimes. "What's the orbital velocity of the moon?" "What?" "Oh, you'd like something simpler?

I [...] vowed that rather than let Alzheimer's take me, I would take it. I would live my life as ever to the full and die, ­before the disease mounted its last ­attack, in my own home, in a chair on the lawn, with a brandy in my hand to wash down whatever modern ­version of the "Brompton cocktail" some ­helpful medic could supply. And with ­Thomas Tallis on my iPod, I would shake hands with Death.

"There's a door," he whispered. "Where does it go?" "It stays where it is, I think," said Rincewind.

Aziraphale. The Enemy, of course. But an enemy for six thousand years now, which made him a sort of friend.