Carrot emerged, waving a small yellowing sheet. Vimes squinted at it.

'Looks like nonsense to me,' he said, eventually. 'It's not dwarfish, I know that. But these symbols – these things I've seen before. Or something like them.' He passed the paper back to Carrot. 'What can you make of it?'

Carrot frowned. 'I could make a hat,' he said, 'or a boat. Or a sort of chrysanthemum—'

'I mean the symbols. These symbols, just here.'

'Dunno, captain. They do look familiar, though. Sort of . . . like alchemists' writing?'

'Oh, no!' Vimes put his hands over his eyes. 'Not the bloody alchemists! Oh, no! Not that bloody gang of mad firework merchants! I can take the Assassins, but not those idiots! No! Please! What time is it?'

Carrot glanced at the hourglass on his belt. 'About half past eleven, captain.'

'Then I'm off to bed. Those clowns can wait until tomorrow. You could make me a happy man by telling me that this paper belonged to Hammerhock.'

'Doubt it, sir.'

'Me too. Come on. Let's go out through the back door.'

Carrot squeezed through.

'Mind your head, sir.'

Vimes, almost on his knees, stopped and stared at the doorframe.

'Well, corporal,' he said eventually, 'we know it wasn't a troll that did it, don't we? Two reasons. One, a troll couldn't get through this door, it's dwarf sized.'

'What's the other reason, sir?'

Vimes carefully pulled something off a splinter on the low door lintel.

'The other reason, Carrot, is that trolls don't have hair.'

The couple of strands that had been caught in the grain of the beam were red and long. Someone had left them there inadvertently. Someone tall. Taller than a dwarf, anyway.

Vimes peered at them. They looked more like threads than hair. Fine red threads. Oh, well. A clue was a clue.

He carefully folded them up in a scrap of paper borrowed from Carrot's notebook, and handed them to the corporal.

'Here. Keep this safe.'

They crawled out into the night. There was a narrow, plank walkway attached to the walls, and beyond that was the river.

Vimes straightened up carefully.

'I don't like this, Carrot,' he said. 'There's something bad underneath all this.'

Carrot looked down.

'I mean, there are hidden things happening,' said Vimes, patiently.

'Yes, sir.'

'Let's get back to the Yard.'

They proceeded to the Brass Bridge, quite slowly, because Carrot cheerfully acknowledged everyone they met. Hard-edged ruffians, whose normal response to a remark from a Watchman would be genteelly paraphrased by a string of symbols generally found on the top row of a typewriter's keyboard, would actually smile awkwardly and mumble something harmless in response to his hearty, 'Good evening, Masher! Mind how you go!'

Vimes stopped halfway across the bridge to light his cigar, striking a match on one of the ornamental hippos. Then he looked down into the turbid waters.

'Carrot?'

'Yes, captain?'

'Do you think there's such a thing as a criminal mind?'

Carrot almost audibly tried to work this out.

'What . . . you mean like . . . Mr Cut-Me-Own-Throat Dibbler, sir?'

'He's not a criminal.'

'You have eaten one of his pies, sir?'

'I mean . . . yes . . . but . . . he's just geographically divergent in the financial hemisphere.'

'Sir?'

'I mean he just disagrees with other people about the position of things. Like money. He thinks it should all be in his pocket. No, I meant—' Vimes closed his eyes, and thought about cigar smoke and flowing drink and laconic voices. There were people who'd steal money from people. Fair enough. That was just theft. But there were people who, with one easy word, would steal the humanity from people. That was something else.

The point was. . . well, he didn't like dwarfs and trolls. But he didn't like anyone very much. The point was that he moved in their company every day, and he had a right to dislike them. The point was that no fat idiot had the right to say things like that.

He stared at the water. One of the piles of the bridge was right below him; the Ankh sucked and gurgled around it. Debris – baulks of timber, branches, rubbish – had piled up in a sort of sordid floating island. There was even fungus growing on it.

What he could do with right now was a bottle of Bearhugger's. The world swam into focus when you looked at it through the bottom of a bottle.

Something else swam into focus.

Doctrine of signatures, thought Vimes. That's what the herbalists call it. It's like the gods put a 'Use Me' label on plants. If a plant looks like a part of the body, it's good for ailments peculiar to that part. There's teethwort for teeth, spleenwort for . . . spleens, eyebright for eyes . . . there's even a toadstool called Phallus impudicus, and I don't know what that's for but Nobby is a big man for mushroom omelettes. Now . . . either that fungus down there is exactly the medicine for hands, or . . .

Vimes sighed.

'Carrot, can you go and get a boathook, please?'

Carrot followed his gaze.

'Just to the left of that log, Carrot.'

'Oh, no!'

'I'm afraid so. Haul it out, find out who he was, make out a report for Sergeant Colon.'

The corpse was a clown. Once Carrot had climbed down the pile and moved the debris aside, he floated face up, a big sad grin painted on his face.

'He's dead!'

'Catching, isn't it?'

Vimes looked at the grinning corpse. Don't investigate. Keep out of it. Leave it to the Assassins and bloody Quirke. These are your orders.

'Corporal Carrot?'

'Sir?'

These are your orders . . .

Well, damn that. What did Vetinari think he was? Some kind of clockwork soldier?

'We're going to find out what's been going on here.'

'Yes, sir!'

'Whatever else happens. We're going to find out.'

The river Ankh is probably the only river in the universe on which the investigators can chalk the outline of the corpse.

'Dear Sgt Colon,

'I hope you are well. The weather is Fine. This is a corpse who, we fished out of the river last night but, we don't know who he is except he is a member of the Fools' Guild called Beano. He has been seriously hit on the back of the head and has been stuck under the bridge for some time, he is not a Pretty sight. Captain Vimes says to find out things. He says he thinks it is mixed up with the Murder of Mr Hammerhock. He says talk to the Fools. He says Do It. Also please find attached Piece of Paper. Captain Vimes says, try it out on the Alchemists—'

Sergeant Colon stopped reading for a while to curse all alchemists.

'—because it is Puzzling Evidence. Hoping this finds you in Good Health, Yours Faithfully, Carrot Ironfoundersson, (Cpl).'

The sergeant scratched his head. What the hell did that all mean?

Just after breakfast a couple of senior jesters from the Fools' Guild had come to pick up the corpse. Corpses in the river . . . well, there was nothing very unusual about that. But it wasn't the way clowns died, usually. After all, what did a clown have that was worth stealing? What sort of danger was a clown?

As for the alchemists, he was blowed if he was—

Of course, he didn't have to. He looked up at the recruits. They had to be good for something.

Cuddy and Detritus – don't salute! - I've got a little job fotr you. Just take this piece of paper to the Alchemists'

Guild, all right? And ask one of the loonies to tell you what he makes of it.'

'Where's the Alchemists' Guild, sergeant?' said Cuddy.

'In the Street of Alchemists, of course,' said Colon, 'at the moment. But I should run, if I was you.'

The Alchemists' Guild is opposite the Gamblers' Guild. Usually. Sometimes it's above it, or below it, or falling in bits around it.

The gamblers are occasionally asked why they continue to maintain an establishment opposite a Guild which accidentally blows up its Guild Hall every few months, and they say: 'Did you read the sign on the door when you came in?'

The troll and the dwarf walked towards it, occasionally barging into each other by deliberate accident.

'Anyway, you so clever, he gave paper to me?'

'Hah! Can you read it, then? Can you?'

'No, I tell you to read it. That called del-eg-ay-shun.'

'Hah! Can't read! Can't count! Stupid troll!'

'Not stupid!'

'Hah! Yes? Everyone knows trolls can't even count up to four!'[11]

'Eater of rats!'

'How many fingers am I holding up? You tell me, Mr Clever Rocks in the Head.'

'Many,' Detritus hazarded.

'Har har, no, five. You'll be in big trouble on payday. Sergeant Colon'11 say, stupid troll, he won't know how many dollars I give him! Hah! How come you read the notice about joining the Watch, anyway? Got someone to read it to you?'

'How come you read notice? Get someone to hold you up?'

They walked into the door of the Alchemists' Guild.

'I knock. My job!'

'I'll knock!'

When Mr Sendivoge, the Guild secretary, opened the door it was to find a dwarf hanging on the knocker and being swung up and down by a troll. He adjusted his crash helmet.

'Yes?' he said.

Cuddy let go.

Detritus'massive brows knitted.

'Er. You loony bastard, what you make of this?' he said.

Sendivoge stared from Detritus to the paper. Cuddy was struggling to get around the troll, who was almost completely blocking the doorway.

'What'd you go and call him that for?'

'Sergeant Colon, he said—'

'I could make a hat out of it,' said Sendivoge, 'or a string of dollies, if I could get some scissors—'

'What my . . . colleague means, sir, is can you help us in our inquiries in re the writing on this alleged piece of paper here?' said Cuddy. 'That bloody hurt!'

Sendivoge peered at him.

'Are you Watchmen?' he said.

'I'm Lance-Constable Cuddy and this,' said Cuddy, gesturing upwards, 'is Lance-trying-to-be-Constable Detritus – don't salu-oh . . .'

There was a thump, and Detritus slumped sideways.

'Suicide squad, is he?' said the alchemist.

'He'll come round in a minute,' said Cuddy. 'It's the saluting. It's too much for him. You know trolls.'

Sendivoge shrugged and stared at the writing.

'Looks . . . familiar,' he said. 'Seen it somewhere before. Here . . . you're a dwarf, aren't you?'

'It's the nose, isn't it?' said Cuddy. 'It always gives me away.'

'Well, I'm sure we always try to be of help to the community,' said Sendivoge. 'Do come in.'

Cuddy's steel-tipped boots kicked Detritus back into semi-sensibility, and he lumbered after them.

'Why the, er, why the crash helmet, mister?' said Cuddy, as they walked along the corridor. All around them was the sound of hammering. The Guild was usually being rebuilt.

Sendivoge rolled his eyes.

'Balls,' he said, 'billiard balls, in fact.'

'I knew a man who played like that,' said Cuddy.

'Oh, no. Mr Silverfish is a good shot. That tends rather to be the problem, in fact.'

Cuddy looked at the crash helmet again.

'It's the ivory, you see.'

'Ah,' said Cuddy, not seeing, 'elephants?'

'Ivory without elephants. Transmuted ivory. Sound commercial venture.'

'I thought you were working on gold.'

'Ah, yes. Of course, you people know all about gold,' said Sendivoge.

'Oh, yes,' said Cuddy, reflecting on the phrase 'you people'.

'The gold,' said Sendivoge, thoughtfully, 'is turning out to be a bit tricky . . .'

'How long have you been trying?'

'Three hundred years.'

'That's a long time.'

'But we've been working on the ivory for only a week and it's going very well!' said the alchemist quickly.

Except for some side effects which we'll doubtless soon be able to sort out.'