The mail, Mr Groat?

'The mail, Mr Groat? Sticking undelivered mail wherever there's a space isn't tampering with it?'

'That's more . . . delaying the mail, sir. Just, er . . . slowing it down. A bit. It's not like there's any intention of never delivering it, sir.' Moist stared at Groat's worried expression. He felt that sense of shifting ground you experience when you realize that you're dealing with someone whose world is connected with your own only by their fingertips. Not a hermit, he thought, more like a shipwrecked mariner, living in this dry desert island of a building while the world outside moves on and all sanity evaporates. 'Mr Groat, I don't want to, you know, upset you or anything, but there's thousands of letters out there under a thick layer of pigeon guano . . .' he said slowly. 'Actually, on that score, sir, things aren't as bad as they seem,' Groat said, and paused to suck noisily on his natural cough lozenge. 'It's very dry stuff, pigeon doings, and forms quite a hard protective crust on the envelopes . . .'

'Why are they all here, Mr Groat?' said Moist. People skills, he remembered. You're not allowed to shake him. The Junior Postman avoided his gaze. 'Well, you know how it is . . .' he tried. 'No, Mr Groat. I don't think I do.'

'Well . . . maybe a man's busy, got a full round, maybe it's Hogswatch, lots of cards, see, and the inspector is after him about his timekeeping, and so maybe he just shoves half a bag of letters somewhere safe . . . but he will deliver 'em, right? I mean, it's not his fault if they keeps pushing, sir, pushing him all the time. Then it's tomorrow and he's got an even bigger bag, 'cos they're pushing all the time, so he reckons, I'll just drop a few off today, too, 'cos it's my day off on Thursday and I can catch up then, but you see by Thursday he's behind by more'n a day's work because they keeps on pushing, and he's tired anyway, tired as a dog, so he says to himself, got some leave coming up soon, but he gets his leave and by then - well, it all got very nasty towards the end. There was . . . unpleasantness. We'd gone too far, sir, that's what it was, we'd tried too hard. Sometimes things smash so bad it's better to leave it alone than try to pick up the pieces. I mean, where would you start?'

'I think I get the picture,' said Moist.