In theory, the only problem in Fred’s life now was his door.

“The Historians’ Guild say we’ve got to preserve as much of the old fabric as possible, Fred,” said Vimes.

“I know that, sir, but…well, ‘The Twaddle Room,’ sir? I mean, really?”

“Nice brass plate, though, Fred,” said Vimes. “It’s what they called the basic soft drink syrup, I’m told. Important historical fact. You could stick a piece of paper over the top of it.”

“We do that, sir, but the lads pull it off and snigger.”

Vimes sighed. “Sort it out, Fred. If an old sergeant can’t sort out that sort of thing, the world has become a very strange place. Is that all?”

“Well, yes, sir, really. But—”

“C’mon, Fred, it’s going to be a busy day.”

“Have you heard of Mr. Shine, sir?”

“Do you clean stubborn surfaces with it?” said Vimes.

“Er…what, sir?” said Fred. No one did perplexed better than Fred Colon. Vimes felt ashamed of himself.

“Sorry, Fred. No, I haven’t heard of Mr. Shine. Why?”

“Oh…nothing, really. ‘Mr. Shine, him Diamond!’ Seen it on walls a few times lately. Troll graffiti; you know, carved in deep. Seems to be causing a buzz among the trolls. Important, maybe?”

Vimes nodded. You ignored the writing on the walls at your peril. Sometimes it was the city’s way of telling you if not what was on its bubbling mind then at least what was in its creaking heart.

“Well, keep listening, Fred. I’m relying on you not to let a buzz become a sting,” said Vimes with extra cheerfulness to keep the man’s spirits up. “And now I’ve got to see our vampire.”

“Best of luck, Sam. I think it’s going to be a long day.”

Sam, thought Vimes, as the old sergeant went out. Gods know he’s earned it, but he only calls me Sam when he’s really worried. Well, we all are.

We’re waiting for the first shoe to drop.

Vimes unfolded the copy of the Times that Cheery had left on his desk. He always read it at work, to catch up on the news that Willikins had thought it unsafe to hear whilst shaving.

Koom Valley, Koom Valley. Vimes shook out the paper and saw Koom Valley everywhere. Bloody, bloody Koom Valley. Gods damn the wretched place, although obviously they had already done so—damned it and then forsaken it. Up close it was just another rocky wasteland in the mountains. In theory, it was a long way away, but it seemed to be getting a lot closer lately. Koom Valley wasn’t really a place now, not anymore. It was a state of mind.

If you wanted the bare facts, it was where the dwarfs had ambushed the trolls and/or the trolls had ambushed the dwarfs, one ill-famed day under unkind stars. Oh, they’d fought one another since Creation, as far as Vimes understood it, but at the Battle of Koom Valley that mutual hatred became, as it were, Official, and, as such, had developed a kind of mobile geography. Where any dwarf fought any troll, there was Koom Valley. Even if it was a punch-up in a pub, it was Koom Valley. It was part of the mythology of both races, a rallying cry, the ancestral reason why you couldn’t trust those short, bearded/big, rocky bastards.

There had been plenty of such Koom Valleys since that first one. The war between the dwarfs and the trolls was a battle of natural forces, like the war between the wind and the waves. It had a momentum of its own.

Saturday was Koom Valley Day, and Ankh-Morpork was full of trolls and dwarfs and you know what? The further trolls and dwarfs got from the mountains, the more that bloody, bloody Koom Valley mattered. The parades were okay; the Watch had gotten good at keeping them apart, and anyway they were in the morning, when everyone was still mostly sober. But when the dwarf bars and the troll bars emptied out in the evening, hell went for a stroll with its sleeves rolled up.

In the bad old days, the Watch would find business elsewhere, and only turned up when stewed tempers had run their course. Then they’d bring out the hurry-up wagon and arrest every troll and dwarf too drunk, dazed, or dead to move. It was simple.

That was then. Now there were too many dwarfs and trolls—no, mental correction—the city had been enriched by vibrant, growing communities of dwarfs and trolls…and there was more…yes, call it venom in the air. Too much ancient politics, too many chips handed down from shoulder to shoulder. Too much boozing, too.

And then, just when you thought it was as bad as it could be, up popped Grag Hamcrusher and his chums. Deep-downers, they were called, dwarfs as fundamental as the bedrock. They’d turned up a month ago, occupied some old house in Treacle Street, and had hired a bunch of local lads to open up the basements. They were “grags.” Vimes knew just enough dwarfish to know that “grag” meant “renowned master of dwarfish lore,” but Hamcrusher had mastered it in his own special way. He preached the superiority of dwarf over troll, and that the duty of every dwarf was to follow in the footsteps of their forefathers and remove trollkind from the face of the world. It was written in some holy book, apparently, so that made it okay, and probably compulsory.

Young dwarfs listened to him, because he talked about history and destiny and all the other words that always got trotted out to put a gloss on slaughter. It was heady stuff, except that brains weren’t involved. Malign idiots like him were the reason you saw dwarfs walking around now not just with the “cultural” battle-axes but heavy mail, chains, morningstars, broadswords…all the dumb, in-your-face swaggering that was known as “clang.”

Trolls listened, too. You saw more lichen, more clan graffiti, more body carving, and much, much bigger clubs being dragged around.

It hadn’t always been like this. Things had loosened up a lot in the last ten years or so. Dwarfs and trolls as races would never be chums, but the city stirred them together, and it had seemed to Vimes that they had managed to get along with no more than surface abrasions.

Now the melting pot was full of lumps again.

Gods damn Hamcrusher. Vimes itched to arrest him. Technically, he was doing nothing wrong, but that was no barrier to a copper who knew his business. He could certainly get him under “Behavior Likely To Cause A Breach Of The Peace.” Vetinari had been against it, though. He’d said it’d only inflame the situation, but how much worse could it get?

Vimes closed his eyes and recalled that little figure, dressed in heavy black-leather robes and hooded so that he would not commit the crime of seeing daylight. A little figure, but with big words. He remembered: “Beware of the troll. Trust him not. Turn him from your door. He is nothing, a mere accident of forces, unwritten, unclean, the mineral world’s pale, jealous echo of living, thinking creatures. In his head, a rock; in his heart, a stone. He does not build, he does not delve, he neither plants nor harvests. His nascence was a deed of theft and everywhere he drags his club he steals. When not thieving, he plans theft. The only purpose in his miserable life is its ending, relieving from the wretched rock his all-too-heavy burden of thought. I say this in sadness. To kill the troll is no murder. At its very worst, it is an act of charity.”

It was about that time that the mob had broken into the hall.

That was how much worse it could be. Vimes blinked at the newspaper again, this time seeking anything that dared suggest that people in Ankh-Morpork still lived in the real world—

“Oh, damn!” He got up and hurried down the stairs, where Cheery practically cowered at his thundering approach.

“Did we know about this?” he demanded, thumping the paper down on the Occurrences Ledger.

“Know about what, sir?” said Cheery nervously.

Vimes prodded a short, illustrated article on page four, his finger stabbing at the page.

“See that?” he growled. “That pea-brained idiot at the Post Office has only gone and issued a Koom Valley stamp!”

The dwarf looked nervously at the article. “Er…two stamps, sir,” she said.

Vimes looked closer. He hadn’t taken in much of the detail before the red mist descended. Oh yes, two stamps. They were very nearly identical. They both showed Koom Valley, a rocky area ringed by mountains. They both showed the battle. But in one, little figures of trolls were pursuing dwarfs from right to left, and in the other, dwarfs were chasing trolls from left to right. Koom Valley, where the trolls ambushed the dwarfs and the dwarfs ambushed the trolls. Vimes groaned. Pick your own stupid history, a snip at ten pence, highly collectible.

“‘The Koom Valley Memorial Issue,’” he read. “But we don’t want them to remember it! We want them to forget it!”

“It’s only stamps, sir,” said Cheery. “I mean, there’s no law against stamps…”

“There ought to be one against being a bloody fool!”

“If there was, sir, we’d be on overtime every day!” said Cheery, grinning.

Vimes relaxed a little. “Yep, and no one could build cells fast enough. Remember the cabbage-scented stamp last month? ‘Send your expatriate sons and daughters the familiar odor of home’? They actually caught fire if you put too many of them together!”

“I still can’t get the smell out of my clothes, sir.”

“There are people living a hundred miles away who can’t, I reckon. What did we do with the bloody things in the end?”

“I put them in No. 4 evidence locker and left the key in the lock,” said Cheery.

“But Nobby Nobbs always steals anything that—” Vimes began.

“That’s right, sir!” said Cheery happily. “I haven’t seen them for weeks.”

There was a crash from the direction of the canteen, followed by shouting. Something in Vimes, perhaps the very part of him that had been waiting for the first shoe, propelled him across the office, down the passage, and to the canteen’s doorway at a speed that left dust spiraling on the floor.

What met his eyes was a tableau in various shades of guilt. One of the trestle tables had been knocked over. Food and cheap tinware were strewn across the floor. On one side of the mess was troll Constable Mica, currently being held between troll Constables Bluejohn and Schist; on the other was dwarf Constable Brakenshield, currently being lifted off the ground by probably human Corporal Nobbs and definitely human Constable Haddock.

There were watchmen at the other tables, too, all caught in the act of rising. And, in the silence, audible only to the fine-tuned ears of a man searching for it, was the sound of hands pausing an inch away from the weapon of choice and very slowly being lowered.

“All right,” said Vimes in the ringing vacuum. “Who’s going to be the first to tell me a huge whopper? Corporal Nobbs?”

“Well, Mr. Vimes,” said Nobby Nobbs, dropping the mute Brakensheild to the floor, “…er…Brakensheild here…picked up Mica’s…yes, picked up Mica’s mug by mistake, as it were…and…we all spotted that and jumped up, yes…” Nobby speeded up now, the really steep fibs now successfully negotiated, “…and that’s how the table got knocked over…’cos,” and here Nobby’s face assumed an expression of virtuous imbecility that was really quite frightening to see, “he’d have really hurt himself if he’d taken a swig of troll coffee, sir.”

Inside, Vimes sighed. As stupid, lame excuses went, it wasn’t actually a bad one. For one thing, it had the virtue of being completely unbelievable. No dwarf would come close to picking up a mug of troll expresso, which was a molten chemical stew with rust sprinkled on the top. Everyone knew this, just as everyone knew that Vimes could see that Brakensheild was holding an axe over his head and Constable Bluejohn was still frozen in the act of wrenching a club off Mica. And everyone knew, too, that Vimes was in the mood to sack the first bloody idiot to make a wrong move, and probably anyone standing near him.

“That’s what it was, was it?” said Vimes. “So it wasn’t, as it might be, someone making a nasty remark about a fellow officer and others of his race, perhaps? Some little bit of stupidity to add to the mess of it that’s floating around the streets right now?”

“Oh, nothing like that, sir,” said Nobby. “Just one of them…things.”

“Nearly a nasty accident, was it?” said Vimes.

“Yessir!”

“Well, we don’t want any nasty accidents, do we, Nobby…”

“Nosir!”

“None of us want nasty accidents, I expect,” said Vimes, looking around the room. Some of the constables, he was grimly glad to see, were sweating with the effort of not moving. “And it’s so easy to have ’em, when your mind isn’t firmly on the job. Understood?”

There was a general muttering.

“I can’t hear you!”

This time there were audible riffs on the theme of “Yessir!”

“Right,” snapped Vimes. “Now get out there and keep the peace, because as sure as hell you won’t do it in here!” He directed a special glare at Constables Brakenshield and Mica, and strode back to the main office, where he almost bumped into Sergeant Angua.

“Sorry, sir, I was just fetching—” she began.

“I sorted it out, don’t worry,” said Vimes. “But it was that close.”

“Some of the dwarfs are really on edge, sir. I can smell it,” said Angua.

“You and Fred Colon,” said Vimes.

“I don’t think it’s just the Hamcrusher thing, sir. It’s something…dwarfish.”

“Well, I can’t beat it out of them. And just when the day couldn’t get any worse, I’ve got to interview a damned vampire.”

Too late Vimes saw the urgent look in Angua’s eyes.

“Ah…I think that would be me,” said a small voice behind him.