`Don't let them go through first!' said Angua through gritted teeth. `Trail is ... faint!'

Carrot drew his sword with one hand and held up his badge with the other.

`City Watch!' he roared. `Lower your weapons, please! Thank you!'

The squad slowed, which meant that, in the nature of these things, those at the back piled into the hesitant ones in front.

`This is a crime scene!' Carrot announced. `I am still the smelter! Mr Ardent, are you there? Do you have guards on the other side of this door?'

Ardent pushed through the throng of dwarfs. `No, I believe not,' he said. `Is the troll still behind it?'

Carrot glanced at Sally, who shrugged. Vampires had never

developed the ability to listen for troll hearts. There was no point.

`Possibly, but I don't think so,' said Carrot. `Please unlock it. We might yet find a trail!'

`Captain Carrot, you know that the safety of the mine must always come first!' said Ardent. `Of course you must give chase. But first we will open the door and make certain there is no danger behind it. You must concede us that.'

`Let them,' hissed Angua. `It'll be a clearer scent. I'll be okay.'

Carrot nodded, and whispered back, `Well done!'

Under her flesh, she felt her tail want to wag. She wanted to lick his face. It was the dog part of her doing the thinking. You're a good dog. It was important to be a good dog.

Carrot pulled her aside as a couple of dwarfs approached the door purposefully.

`But it's long gone,' she murmured, as two more dwarfs came up behind the first two. `The scent's twelve hours old, at least-'

`What are they doing?' said Carrot, half to himself. The two new dwarfs were covered from head to toe in leather, like Ardent, but wore mail over the top of it; their helmets were quite unadorned, but covered the whole face and head, with only a slit for the eyes. Each dwarf carried a large black pack on his back and held a lance in front of him.

`Oh no,' said Carrot, `surely not here-'

At a word of command, the door was swung open, revealing only darkness beyond.

The lances spat flame, long yellow tongues of it, and the black dwarfs walked slowly along behind them. Smoke, heavy and greasy, filled the air.

Angua fainted.

Darkness.

Sam Vimes struggled up the hill, tired to the bone.

It was warm, warmer than he'd expected. Sweat stung his eyes.

Water splashed under his feet and made his boots slip. And, ahead,

up the slope, a child was screaming.

He knew he was shouting. He could hear the breath wheezing in his throat, could feel his lips moving, but he couldn't hear the words he was reciting, over and over again.

The darkness felt like cold ink. Tendrils of it dragged at his mind and his body, slowing him down, pulling him back ... And now they came at him with flames

Vimes blinked, and found himself staring at the fireplace. The flames flicked peacefully.

There was the swish of a dress as Sybil came back into the room, sat down and picked up her darning.

He watched her, dully. She was darning his socks. They had maids in this place and she darned his socks. It wasn't as if they didn't have so much money that he could have a new pair of socks every day. But she'd picked up the idea that it was a wifely duty, and so she did it. It was comforting, in a strange sort of way. It was only a shame that she wasn't in fact any good at mending holes, so Sam ended up with sock heels that were a huge welt of criss-crossing wool. He wore them anyway, and never mentioned it.

`A weapon that fires flame,' he said slowly.

`Yes, sir,' said Carrot.

`Dwarfs have weapons that fire flame.'

`The deep-downers use them to explode pockets of mine-gas,'

said Carrot. `I never expected to see them here!'

`It's a weapon if some bastard points it at me!' said Vimes. `How

much gas did they expect to find in Ankh-Morpork?'

`Sir? Even the river catches fire in a hot summer!

'Okay, okay. I'll grant you that,' Vimes conceded, unwillingly.

`Make sure the word gets out, will you? Anyone seen above ground

with one of those things, we'll shoot first and there will be no point in asking questions afterwards. Good grief, that's all we need. Have you got anything more to tell me, captain?'

`Well, afterwards we did get to see Hamcrusher's body,' said Carrot. `What can I say? On his wrist was the draht that identifies him, and his skin was pale. There was a terrible wound on the back of the head. They say it's Hamcrusher. I can't prove it. What I can say is that he didn't die where they said he did, or when they said he did.'

`Why?' said Vimes.

`Blood, sir,' said Sally. `There should have been blood everywhere. I looked at the wound. What that club hit over the head was already a corpse, and he wasn't killed in that tunnel.'

Vimes took several slow breaths. There was so much bad stuff here you needed to take it one horror at a time.

`I'm worried, captain,' he said. `Do you know why? It's because I've got a feeling that very soon I'm going to be asked to confirm that there's evidence that a troll did the deed. Which, my friend, will be like announcing the outbreak of war.'

`You did ask us to investigate, sir,' said Carrot.

`Yes, but I didn't expect you to come back with the wrong result! The whole thing stinks! That clay from Quarry Lane was planted, wasn't it?'

`It must have been. Trolls don't clean their feet much, but walking mud all the way? Not a chance.'

`And they don't leave their clubs behind, either,' growled Vimes. `So it's a set-up, right? But it turns out there really was a troll! Was Angua sure?'

`Positive, sir,' said Carrot. `We've always trusted her nose before. Sorry, sir, she had to go and get some fresh air. She was straining her senses as it was, and she got a lungful of that smoke.'

`I can imagine,' said Vimes. Hells' bells, he thought. We were right on the point where I could tell Vetinari that it looked like some kind

of half-baked inside job faked to look as though a troll did it, and we find out there was a troll. Huh, so much for relying on the evidence.

Sally coughed politely. `Ardent was shocked and frightened when the captain found the skull, sir,' she said. `It wasn't an act. I'm certain of it. He was near collapse with terror. So was Helmclever, the whole time. `Thank you for that, lance-constable,' said Vimes gravely. `I suspect I shall feel the same way when I go out there with a megaphone and shout, "Hello, boys, welcome to the replay of Koom Valley! Hey, let's hold it right here in the city!"'

`I don't think you should actually put it like that, sir,' said Carrot.

`Well, yes, I'll probably try to be a bit more subtle, since you mention it,' said Vimes.

`And it'd be at least the sixteenth battle referred to as Koom Valley,' Carrot went on, `or seventeenth if you include the one in Vilinus Pass, which was more of a fracas. Only three of them were in the original Koom Valley, the one immortalized in Rascal's painting. It's said to be quite accurate. Of course, it took him years.'

`An amazing work,' said Sybil, not looking up from her darning. `It used to belong to my family before we gave it to the museum, you know.'

`Isn't progress a wonderful thing, captain?' said Vimes, pouring as much sarcasm into his tone as possible, since Carrot was so bad at recognizing it. `When we have our Koom Valley, our friend Otto will be able to take a colour iconograph of it in a fraction of a second. Wonderful. It's been a long time since this city was last burned to the ground.'

He ought to be springing into action. Once upon a time, he would have done. But now, perhaps he should take these precious moments to work out what he should do before he sprang.