Discworld – Carpe Jugulum (Terry Pratchett)

It was well after noon before Granny Weatherwax came off the moor, and a watcher might have wondered why it took such a long time to cross a little patch of moor land.

They'd have wondered even more about the little stream. It had cut a rock-studded groove in the peat that a healthy woman could have leapt across, but someone had placed a broad stone across it for a bridge.

She looked at it for a while and then reached into her sack. She took out a long piece of black material and blindfolded herself. Then she walked out across the stone, taking tiny steps with her arms flung. out wide for balance. Halfway across she fell on to her hands and knees and stayed there, panting, for several minutes. Then she crawled forward again, by inches.

A few feet below, the peaty stream rattled happily over the stones.

The sky glinted. It was a sky with blue patches and bits of cloud, but it had a strange look, as though a picture painted on glass had been fractured and then the shards reassembled wrongly. A drifting cloud disappeared against some invisible line and began to emerge in another part of the sky altogether.

Things were not what they seemed. But then, as Granny always said, they never were.