'Remember,' he said, 'let's be careful out there.'

'Yeah,' said Nobby, 'let's be careful to stay in here.'

To understand why dwarfs and trolls don't like each other you have to go back a long way.

They get along like chalk and cheese. Very like chalk and cheese, really. One is organic, the other isn't, and also smells a bit cheesy. Dwarfs make a living by smashing up rocks with valuable minerals in them and the silicon-based lifeform known as trolls are, basically, rocks with valuable minerals in them. In the wild they also spend most of the daylight hours dormant, and that's not a situation a rock containing valuable minerals needs to be in when there are dwarfs around. And dwarfs hate trolls because, after you've just found an interesting seam of valuable minerals, you don't like rocks that suddenly stand up and tear your arm off because you've just stuck a pick-axe in their ear.

It was a state of permanent inter-species vendetta and,

-like all good vendettas, didn't really need a reason any more. It was enough that it had always existed.[5] Dwarfs hated trolls because trolls hated dwarfs, and vice versa.

The Watch lurked in Three Lamps Alley, which was about halfway down Short Street. There was a distant crackle of fireworks. Dwarfs let them off to drive away evil mine spirits. Trolls let them off because they tasted nice.

'Don't see why we can't let 'em fight it out amongst themselves and then arrest the losers,' said Corporal Nobbs. 'That's what we always used to do.'

'The Patrician gets really shirty about ethnic trouble,' said Sergeant Colon moodily. 'He gets really sarcastic about it.'

A thought struck him. He brightened up a little bit.

'Got any ideas, Carrot?' he said.

A second thought struck him. Carrot was a simple lad.

'Corporal Carrot?'

'Sarge?'

'Sort this lot out, will you?'

Carrot peered around the corner at the advancing walls of trolls and dwarfs. They'd already seen each other.

'Right you are, sergeant,' he said. 'Lance-Constables Cuddy and Detritus – don't salute! – you come with me.'

'You can't let him go out there!' said Angua. 'It's certain death!'

'Got a real sense o'duty, that boy,' said Corporal Nobbs. He took a minute length of dog-end from behind his ear and struck a match on the sole of his boot.

'Don't worry, miss,' said Colon. 'He—'

'Lance-Constable,' said Angua.

'What?'

'Lance-Constable,' she repeated. 'Not miss. Carrot says I don't have any sex while I'm on duty.'

To the background of Nobby's frantic coughing, Colon said, very quickly, 'What I mean is, lance-constable, young Carrot's got krisma. Bags of krisma.'

'Krisma?'

'Bags of it.'

The jolting had stopped. Chubby was really annoyed now. Really, really annoyed.

There was a rustling noise. A piece of sacking moved aside and there, staring at Chubby, was another male dragon.

It looked annoyed.

Chubby reacted in the only way he knew how.

Carrot stood in the middle of the street, arms folded, while the two new recruits stood just behind him, trying to keep an eye on both approaching marches at the same time.

Colon thought Carrot was simple. Carrot often struck people as simple. And he was.

Where people went wrong was thinking that simple meant the same thing as stupid.

Carrot was not stupid. He was direct, and honest, and good-natured and honourable in all his dealings. In Ankh-Morpork this would normally have added up to 'stupid' in any case and would have given him the survival quotient of a jellyfish in a blast furnace, but there were a couple of other factors. One was a punch that even trolls had learned to respect. The other was that Carrot was genuinely, almost supernaturally, likeable. He got on well with people, even while arresting them. He had an exceptional memory for names.

For most of his young life he'd lived in a small dwarf colony where there were hardly any other people to know. Then, suddenly, he was in a huge city, and it was as if a talent had been waiting to unfold. And was still unfolding.

He waved cheerfully at the approaching dwarfs.

' 'Morning Mr Cumblethigh! 'Morning, Mr Strong-inthearm!'

Then he turned and waved at the leading troll. There was a muffled 'pop' as a firework went off.

' 'Morning, Mr Bauxite!'

He cupped his hands.

'If you could all just stop and listen to me—' he bellowed.

The two marches did stop, with some hesitation and a general piling up of the people in the back. It was that or walk over Carrot.

If Carrot did have a minor fault, it lay in not paying attention to small details around him when his mind was on other things. So the whispered conversation behind his back was currently escaping him.

'—hah! It was too an ambush! And your mother was an ore—'

'Now then, gentlemen,' said Carrot, in a reasoned and amiable voice, 'I'm sure there's no need for this belligerent manner—'

'—you ambush us too! my great-great-grandfather he at Koom Valley, he tell me!'

'—in our fair city on such a lovely day. I must ask you as good citizens of Ankh-Morpork—'

'—yeah? you even know who your father is, do you?'

'—that, while you must certainly celebrate your proud ethnic folkways, to profit by the example of my fellow officers here, who have sunk their ancient differences—'

'—I smash you head, you roguesome dwarfs!'

'—for the greater benefit of—'

'—I could take you with one hand tied behind my back!'

'—the city, whose badge they are—'

' —you get opportunity! I tie BOTH hands behind you back!'

'—proud and privileged to wear.'

'Aargh!'

'Ooow!'

It dawned on Carrot that hardly anyone was paying any attention to him. He turned.

Lance-Constable Cuddy was upside down, because Lance-Constable Detritus was trying to bounce him on the cobbles by his helmet, although Lance-Constable Cuddy was putting the position to good effect by gripping Lance-Constable Detritus around the knee and trying to sink his teeth into Lance-Constable Detritus' ankle.

The opposing marchers watched in fascination.

'We should do something!' said Angua, from the guards' hiding place in the alley.

'Weeell,' said Sergeant Colon, slowly, 'it's always very tricky, ethnic.'

'Can put a foot wrong very easily,' said Nobby. 'Very thin-skinned, your basic ethnic.'

'Thin-skinned? They're trying to kill one another!'

'It's cultural,' said Sergeant Colon, miserably. 'No sense us tryin' to force our culture on 'em, is there? That's speciesist.'

Out in the street, Corporal Carrot had gone very red in the face.

'If he lays a finger on either of 'em, with all their friends watching,' said Nobby, 'theplan is, we run away like hell—'

Veins stood out on Carrot's mighty neck. He stuck his hands on his waist and bellowed:

'Lance-Constable Detritus! Salute!'

They'd spent hours trying to teach him. Detritus' brain took some time to latch on to an idea, but once it was there, it didn't fade away fast.

He saluted.

His hand was full of dwarf.

So he saluted while holding Lance-Constable Cuddy, swinging him up and over like a small angry club.

The sound of their helmets meeting echoed off the buildings, and it was followed a moment later by the crash of them both hitting the ground.

Carrot prodded them with the toe of his sandal.

Then he turned and strode towards the dwarf marchers, shaking with anger.

In the alleyway, Sergeant Colon started to suck the rim of his helmet out of terror.

'You've got weapons, haven't you?' snarled Carrot at a hundred dwarfs. 'Own up! If the dwarfs who've got weapons don't drop them right this minute the entire parade, and I mean the entire parade, will be put in the cells! I'm serious about this!'

The dwarfs in the front row took a step backwards. There was a desultory tinkle of metallic objects hitting the ground.

'All of them,' said Carrot menacingly. 'That includes you with the black beard trying to hide behind Mr Hamslinger! I can see you, Mr Stronginthearm! Put it down. No-one's amused!'

'He's going to die, isn't he,' said Angua, quietly.

'Funny, that,' said Nobby. 'If we was to try it, we'd be little bits of mince. But it seems to work for him.'

'Krisma,' said Sergeant Colon, who was having to lean on the wall.

'Do you mean charisma?' said Angua.

'Yeah. One of them things. Yeah.'

'How does he manage it?'

'Dunno,' said Nobby. 'S'pose he's an easy lad to like?'

Carrot had turned on the trolls, who were smirking at the dwarfs' discomfiture.

'And as for you,' he said, 'I shall definitely be patrolling around Quarry Lane tonight, and I won't be seeing any trouble. Will I?'

There was a shuffling of huge oversized feet, and a general muttering.

Carrot cupped his hand to his ear.

'I couldn't quite hear,' he said.

There was a louder mutter, a sort of toccata scored for one hundred reluctant voices on the theme of 'Yes, Corporal Carrot.'

'Right. Now off you go. And let's have no more of this nonsense, there's good chaps.'

Carrot brushed the dust off his hands and smiled at everyone. The trolls looked puzzled. In theory, Carrot was a thin film of grease on the street. But somehow it just didn't seem to be happening . . .

Angua said, 'He just called a hundred trolls “good chaps”. Some of them are just down off the mountains! Some of them have got lichen on them!'

'Smartest thing on a troll,' said Sergeant Colon.

And then the world exploded.

The Watch had left before Captain Vimes got back to Pseudopolis Yard. He plodded up the stairs to his office, and sat down in the sticky leather chair. He gazed blankly at the wall.

He wanted to leave the Guard. Of course he did.

It wasn't what you could call a way of life. Not life.

Unsocial hours. Never being certain from one day to the next what the Law actually was, in this pragmatic city. No home life, to speak of. Bad food, eaten when you could; he'd even eaten some of Cut-Me-Own-Throat Dibbler's sausages-in-a-bun before now. It always seemed to be raining or baking hot. No friends, except for the rest of the squad, because they were the only people who lived in your world.

Whereas in a few days he would, as Sergeant Colon had said, be on the gravy boat. Nothing to do all day but eat his meals and ride around on a big horse shouting orders at people.

At times like this the image of old Sergeant Kepple floated across his memory. He'd been head of the Watch when Vimes was a recruit. And, soon afterwards, he retired. They'd all clubbed together and bought him a cheap watch, one of those that'd keep going for a few years until the demon inside it evaporated.

Bloody stupid idea, Vimes thought moodily, staring at the wall. Bloke leaves work, hands in his badge and hourglass and bell, and what'd we get him? A watch.

But he'd still come in to work the next day, with his new watch. To show everyone the ropes, he said; to tidy up a few loose ends, haha. See you youngsters don't get into trouble, haha. A month later he was bringing the coal in and sweeping the floor and running errands and helping people write reports. He was still there five years later. He was still there six years later, when one of the Watch got in early and found him lying on the floor . . .

And it emerged that no-one, no-one, knew where he lived, or even if there was a Mrs Kepple. They had a whip-round to bury him, Vimes remembered. There were just guards at the funeral . . .

Come to think of it, there were always just guards at a guard's funeral.

Of course it wasn't like that now. Sergeant Colon had been happily married for years, perhaps because he and his wife arranged their working lives so that they only met occasionally, normally on the doorstep. But she left him decent meals in the oven, and there was clearly something there; they'd got grandchildren, even, so obviously there had been times when they'd been unable to avoid each other. Young Carrot had to fight young women off with a stick. And Corporal Nobbs . . . well, he probably made his own arrangements. He was said to have the body of a twenty-five year old, although no-one knew where he kept it.