After half an hour of exploration Moist wanted a bath. It was like walking through desert tombs. He felt he was choking on the smell of old paper, as though his throat was filled with yellow dust.

‘I was told I had an apartment here,’ he croaked.

‘Yes, sir,’ said Groat. ‘Me and the lad had a look for it the other day. I heard that it was the other side of your office. So the lad went in on the end of a rope, sir. He said he felt a door, sir, but he’d sunk six feet under the mail by then and he was suffering, sir, suffering … so I pulled him out.’

‘The whole place is full of undelivered mail?’

They were back in the locker room. Groat had topped up the black kettle from a pan of water, and it was steaming. At the far end of the room, sitting at his neat little table, Stanley was counting his pins.

‘Pretty much, sir, except in the basement and the stables,’ said the old man, washing a couple of tin mugs in a bowl of not very clean water.

‘You mean even the postm— my office is full of old mail but they never filled the basement? Where’s the sense in that?’

‘Oh, you couldn’t use the basement, sir, oh, not the basement,’ said Groat, looking shocked. ‘It’s far too damp down here. The letters’d be destroyed in no time.’

‘Destroyed,’ said Moist flatly.

‘Nothing like damp for destroying things, sir,’ said Groat, nodding sagely.

‘Destroying mail from dead people to dead people,’ said Moist, in the same flat voice.

‘We don’t know that, sir,’ said the old man. ‘I mean, we’ve got no actual proof.’

‘Well, no. After all, some of those envelopes are only a hundred years old!’ said Moist. He had a headache from the dust and a sore throat from the dryness, and there was something about the old man that was grating on his raw nerves. He was keeping something back. ‘That’s no time at all to some people. I bet the zombie and vampire population are still waiting by the letter box every day, right?’

‘No need to be like that, sir,’ said Groat levelly, ‘no need to be like that. You can’t destroy the letters. You just can’t do it, sir. That’s Tampering with the Mail, sir. That’s not just a crime, sir. That’s, a, a—’

‘Sin?’ said Moist.

‘Oh, worse’n a sin ,’ said Groat, almost sneering. ‘For sins you’re only in trouble with a god, but in my day if you interfered with the mail you’d be up against Chief Postal Inspector Rumbelow. Hah! And there’s a big difference. Gods forgive’ .

Moist sought for sanity in the wrinkled face opposite him. The unkempt beard was streaked with different colours, either of dirt, tea or random celestial pigment. Like some hermit, he thought. Only a hermit could wear a wig like that.

‘Sorry?’ he said. ‘And you mean that shoving someone’s letter under the floorboards for a hundred years isn’t tampering with it?’

Groat suddenly looked wretched. The beard quivered. Then he started to cough, great hacking, wooden, crackling lumps of cough, that made the jars shake and caused a yellow mist to rise from his trouser bottoms, “scuse me a moment, sir,’ he wheezed, between hacks, and he fumbled in his pocket for a scratched and battered tin. ‘You suck at all, sir?’ he said, tears rolling down his cheeks. He proffered the tin to Moist. ‘They’re Number Threes, sir. Very mild. I make ‘em meself, sir. Nat’ral remedies from nat’ral ingredients, that’s my style, sir. Got to keep the tubes clear, sir, otherwise they turn against you.’

Moist took a large, violet lozenge from the box and sniffed it. It smelled faintly of aniseed.

‘Thank you, Mr Groat,’ he said, but in case this counted as an attempt at bribery, he added sternly: ‘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. You’re lying, Mr Groat. You’re lying by omission. You’re not telling me everything. And what you’re not telling me is very important, isn’t it? I’ve turned lying into an art, Mr Groat, and you’re just a talented amateur.

Groat’s face, unaware of the internal monologue, managed a smile.

‘But the trouble is - what’s your first name, Mr Groat?’ Moist asked.

‘Tolliver, sir.’

‘Nice name… the thing is , Tolliver, that the picture I see in your description is what I might refer to for the purposes of the analogy as a cameo , whereas all this’ - Moist waved his hand to include the building and everything it contained - ‘is a full-sized triptych showing scenes from history, the creation of the world and the disposition of the gods, with a matching chapel ceiling portraying the glorious firmament and a sketch of a lady with a weird smile thrown in for good measure! Tolliver, I think you are not being frank with me.’

‘Sorry about that, sir,’ said Groat, eyeing him with a sort of nervous defiance.

‘I could have you sacked, you know,’ said Moist, knowing that this was a stupid thing to say.

‘You could, sir, you could try doin’ that,’ said Groat, quietly and slowly. ‘But I’m all you got, apart from the lad. And you don’t know nuffin’ about the Post Office, sir. You don’t know nuffin’ about the Regulations, neither. I’m the only one that knows what needs doing round here. You wouldn’t last five minutes without me, sir. You wouldn’t even see that the inkwells get filled every day!’

‘Inkwells? Filling inkwells?’ said Moist. ‘This is just an old building full of… of… of dead paper! We have no customers !’

‘Got to keep the inkwells filled, sir. Post Office Regulations,’ said Groat in a steely voice. ‘Got to follow Regulations, sir.’

‘For what? It appears we don’t accept any mail or deliver any mail! We just sit here!’