'But I should go and–'

'And what, Mrs Plinge? said Nanny.

The old woman went pale. Granny Weatherwax could be nasty, but then nastiness was always in the window: you were aware that it might turn up on the menu. Sharpness from Nanny Ogg, though, was like being bitten by a big friendly dog. It was all the worse for being unexpected.

'I daresay you wanted to go and have a word with somebody, did you, Mrs Plinge?' said Nanny softly. 'Someone who might be a little shocked to find his Box full, perhaps? I reckon I could put a name to that someone, Mrs Plinge. Now, if–'

The old woman's hand came up holding a bottle of champagne and then came down hard in an effort to launch the SS Gytha Ogg on to the seas of unconsciousness. The bottle bounced.

Then Mrs Plinge leapt past and scuttled away, her polished little black boots twinkling.

Nanny Ogg caught the doorframe and swayed a little while blue and purple fireworks went off behind her eyes. But there was dwarf in the Ogg ancestry, and that meant a skull you could go mining with.

She stared muzzily at the bottle. 'Year of the Insulted Goat,' she mumbled. ' 'S a good year.'

Then consciousness gained the upper hand.

She grinned as she galloped after the retreating figure. In Mrs Plinge's place she'd have done exactly the same thing, except a good deal harder.

Agnes waited with the others for the curtain to go up. She was one of the crowd of fifty or so townspeople who would hear Enrico Basilica sing of his success as a master of disguise, it being a vital part of the entire process that, while the chorus would listen to expositions of the plot, and even sing along, they would suffer an instant lapse of memory afterwards so that later unmaskings would come as a surprise.

For some reason, without any word being spoken, as many people as possible seemed to have acquired very broad-brimmed hats. Those who hadn't were taking every opportunity to glance upwards.

Beyond the curtain, Herr Trubelmacher launched the overture.

Enrico, who had been chewing a chicken leg, carefully put the bone on a plate and nodded. The waiting stage-hand dashed off.

The opera had begun.

Mrs Plinge reached the bottom of the grand staircase and hung on to the banister, panting.

The opera had started. There was no one around. And no sounds of pursuit, either.

She straightened up, and tried to get her breath back.

'Coo-ee, Mrs Plinge!'

Nanny Ogg, waving the champagne bottle like a club, was already travelling at speed when she hit the first turn in the banister, but she leaned like a professional and kept her balance as she went into the straight, and then tilted again for the next curve...

...which left only the big gilt statue at the bottom. It is the fate of all banisters worth sliding down that there is something nasty waiting at the far end. But Nanny Ogg's response was superb. She swung a leg over as she hurtled downwards and pushed herself off, her nailed boots leaving grooves in the marble as she spun to a halt in front of the old woman.

Mrs Plinge was lifted off her feet and carried into the shadows behind another statue.

'You don't want to try and outrun me, Mrs Plinge,' Nanny whispered, as she clamped a hand firmly over Mrs Plinge's mouth. 'You just want to wait here quietly with me. And don't go thinking I'm nice. I'm only nice compared to Esme, but so is practic'ly everyone...'

'Mmf!'

With one hand tightly around Mrs Plinge's arm and another over her mouth, Nanny peered round the statue. She could hear the singing, far off:

Nothing else happened. After a while, she started to fret. Perhaps he'd taken fright. Perhaps Mrs Plinge had left him some sort of signal. Perhaps he'd decided that the world was currently too dangerous for Ghosts, although Nanny doubted he could ever decide that...

At this rate the first act would be over before–

A door opened somewhere. A lanky figure in a black suit and a ridiculous beret crossed the foyer and went up the stairs. At the top, they saw it turn in the direction of the Boxes and disappear.

'Y'see,' said Nanny, trying to get the stiffness out of her limbs, 'the thing about Esme is, she's stupid...'

'Mmf?'

'...so she thinks that the most obvious way, d'y'see, for the Ghost to get in and out of the Box is through the door. If you can't find a secret panel, she reckons, it's because it ain't there. A secret panel that ain't there is the best kind there is, the reason bein', no bugger can find it. That's where you people all think too operatic, see? You're all cooped up in this place, listening to daft plots what don't make sense, and I reckon it does something to your minds. People can't find a trapdoor so they say, oh, deary me, what a hidden trapdoor it must be. Whereas a normal person, e.g., me and Esme, we'd say: Maybe there ain't one, then. And the best way for the Ghost to get around the place without being seen is for him to be seen and not noticed. Especially if he's got keys. People don't notice Walter. They looks the other way.'

She gently released her grip. 'Now, I don't blame you, Mrs Plinge, 'cos I'd do the same for one of mine, but you'd have done better to trust Esme right at the start. She'll help you if she can.'

Nanny let Mrs Plinge go, but kept a grip on the champagne bottle, just in case.

'What if she can't?' said Mrs Plinge bitterly.

'You think Walter did those murders?'

'He's a good boy!'

'I'm sure that's the same as a "no", isn't it?'

'They'll put him in prison!'

'If he done them murders, Esme won't let that happen,' said Nanny.

Something sank into Mrs Plinge's not very alert mind. 'What do you mean, she won't let that happen?' she said.

'I mean,' said Nanny, 'that if you throw yourself on Esme's mercy, you better be damn' sure you deserve to bounce.'

'Oh, Mrs Ogg!'

'Now, don't you worry about anything,' said Nanny, perhaps a little late under the circumstances. It occurred to her that the immediate future might be a little bit easier on everyone if Mrs Plinge got some well-earned rest. She fumbled in her clothing and produced a bottle, half-full of some cloudy orange liquid. 'I'll just give you a sip of a little something to calm your nerves...'

'What is it?'

'It's a sort of tonic,' said Nanny. She flicked the cork out with her thumb; on the ceiling above her, the paint crinkled. 'It's made from apples. Well... mainly apples...'

Walter Plinge stopped outside Box Eight and looked around.

Then he removed his beret and pulled out the mask. The beret went into his pocket.

He straightened up, and it looked very much as though Walter Plinge with the mask on was several inches taller.

He took a key from his pocket and unlocked the door, and the figure that stepped into the Box did not move like Walter Plinge. It moved as though every nerve and muscle were under full and athletic control.

The sounds of the opera filled the Box. The walls had been lined with red velvet and were hung with curtains. The chairs were high and well padded.

The Ghost slipped into one of them and settled down.

A figure leaned forward out of the other chair and said, 'You carrn't havve my fisssh eggs!'

The Ghost leapt up. The door clicked behind him.

Granny stepped out from the curtains.

'Well, well, we meet again,' she said.

He backed away to the edge of the Box.

'I shouldn't think you could jump,' said Granny. 'It's a long way down.' She focused her best stare on the white mask. 'And now, Mister Ghost–'

He sprang back on to the edge of the Box, saluted Granny flamboyantly, and leapt upwards.

Granny blinked.

Up until now the Stare had always worked...

'Too damn' dark,' she muttered. 'Greebo!'

The bowl of caviar flew out of his nervous fingers and caused a Fortean experience somewhere in the Stalls.

'Yess, Gran-ny!'

'Catch him! And there could be a kipper in it for you!'

Greebo snarled happily. This was more like it. Opera had begun to pall for him the moment he realized that no one was going to pour a bucket of cold water over the singers. He understood chasing things.

Besides, he liked to play with his friends.

Agnes saw the movement out of the corner of her eye. A figure had jumped out of one of the Boxes and was climbing up to the balcony. Then another figure clambered after it, scrambling over the gilt cherubs.

Singers faltered in mid-note. There was no mistaking the leading figure. It was the Ghost.

The Librarian was aware that the orchestra had stopped playing. Somewhere on the other side of the backcloth the singers had stopped too. There was a buzz of excited conversation and one or two cries.

The hairs all over his body began to prickle. Senses designed to protect his species in the depths of the rainforest had adjusted nicely to the conditions of a big city, which was merely drier and had more carnivores.

He picked up the discarded bow-tie and, with great deliberation, tied it around his forehead so that he looked like a really formal Kamikaze warrior. Then he threw away the opera score and stared blankly into space for a moment. He knew instinctively that some situations required musical accompaniment.

This organ lacked what he considered the most basic of facilities, such as the Thunder pedal, a 128-foot Earthquake pipe and a complete keyboard of animal noises, but he was certain there was something exciting that could be done in the bass register.

He stretched out his arms and cracked his knuckles. This took some time.

And then he began to play.

The Ghost danced along the edge of the balcony, scattering hats and opera-glasses. The audience watched in astonishment, and then began to clap. They couldn't quite see how it fitted into the plot of the opera–but this was an opera, after all.

He reached the centre of the balcony, trotted a little way up the aisle, and then turned and ran down again at speed. He reached the edge, jumped, jumped again, soared out into the auditorium...

...and landed on the chandelier, which jingled and began to sway gently.

The audience stood up and applauded as he climbed through the jangling tiers towards the central cable.

Then another shape clambered over the edge of the balcony and loped along in pursuit. This was a stockier figure than the first man, one-eyed, broad in the shoulders and tapering at the waist; he looked evil in an interesting kind of way, like a pirate who really understood the words 'Jolly Roger'. He didn't even take a run but, when he reached the closest part to the chandelier, simply launched himself into space.

It was clear that he wasn't going to make it.

And then it wasn't clear how he did.

Those watching through opera-glasses swore later that the man thrust out an arm which merely seemed to graze the chandelier and yet was then somehow able to swivel his entire body in mid-air:

A couple of people swore even harder that, just as the man reached out, his fingernails appeared to grow by several inches.

The huge glass mountain swung ponderously on its rope and, as it reached the end of the swing, Greebo swung out further, like a trapeze artist. There was an appreciative 'oo' from the audience.

He twisted again. The chandelier hesitated for a moment at the extremity of its arc, and then swept back again.

As it jangled and creaked over the Stalls the hanging figure swung upwards, let go and did a backward somersault that dropped him in the middle of the crystals. Candles and prisms were scattered over the seats below.

And then, with the audience clapping and cheering, he scrambled up the rope after the fleeing Ghost.

Henry Lawsy tried to move his arm, but a fallen crystal had stapled the sleeve of his coat to his armrest.

It was a quandary. He was pretty sure this wasn't supposed to happen, but he wasn't certain.

Around him he could hear people hissing questions.

'Was that part of the plot?'

'I'm sure it must have been.'

'Oh, yes. Yes. It certainly was,' said someone further down the row, authoritatively. 'Yes. Yes. The famous chase scene. Indeed. Oh, yes. They did it in Quirm, you know.'

'Oh...yes. Yes, of course. I'm sure I heard about it...,

'I thought it was bloody good,' said Mrs Lawsy. 'Mother!'

'About time something interesting happened. You should've told me. I'd've put my glasses on.'

Nanny Ogg pounded up the back stairs towards the fly loft.

'Something's gone wrong!' she muttered under her breath as she took the stairs two at a time. 'She reckons she's only got to stare at 'em and they're toffee in her hands, and then who has to sort it out afterwards, eh? Go on, guess...'

The ancient wooden door at the top of the stairs gave way to Nanny Ogg's boot with Nanny Ogg's momentum behind it, and cracked open on to a big, shadowy space. It was full of running figures. Legs flickered in the light of lanterns. People were shouting.

A figure ran straight towards her.

Nanny sprang into a crouch, both thumbs on the cork of the badly shaken champagne bottle she held cradled under one arm.

'This is a magnum,' she said, 'and I'm not afraid to drink it!'

The figure stopped. 'Oh, it's you, Mrs Ogg...'

Nanny's infallible memory for personal details threw up a card. 'Peter, isn't it?' she said, relaxing. 'The one with the bad feet?'

'That's right, Mrs Ogg.'

'The powder I give you is working, is it?'

'They're a lot better now, Mrs Ogg–'

'So what's been happening?'

'Mr Salzella caught the Ghost!'

'Really?'

Now that Nanny's eyes had–managed to discern some order in the chaos, she could see a cluster of people in the middle of the floor, around the chandelier.

Salzella was sitting on the planking. His collar was torn and a sleeve had been ripped off his jacket, but he had a triumphant look in his eyes.

He waved something in the air.

It was white. It looked like a piece of a skull.

'It was Plinge!' he said. 'I tell you, it was Walter Plinge! Why are you all standing around? Get after him!'

'Walter?' said one of the men, doubtfully.

'Yes, Walter!'

Another man hurried up, waving his lantern.

'I saw the Ghost heading up to the roof! And there was some big one-eyed bastard going after him like a scalded cat!'

That's wrong, thought Nanny. Something wrong here.

'To the roof!' shouted Salzella.

'Hadn't we better get the flaming torches first?'

'Flaming torches are not compulsory!'

'Pitchforks and scythes?'

'That's only for vampires!'

'How about just one torch?'

'Get up there now! Understand?'

The curtains closed. There was a smattering of applause which was barely audible above the chatter from the audience.

The chorus turned to one another. 'Was that supposed to happen?'

Dust rained down. Stage-hands were scampering across the gantries far above. Shouts echoed among the ropes and dusty backdrops. A stage-hand ran across the stage, holding a flaming torch.

'Here, what's going on?' said a tenor.

'They've got the Ghost! He's heading for the roof! It's Walter Plinge!'

'What, Walter?'

'Our Walter Plinge?'

'Yes!'

The stage-hand ran on in a trail of sparks, leaving the yeast of rumour to ferment in the ready dough that was the chorus.

'Walter? Surely not!'

'Weeelll... he's a bit odd, isn't he... ?'

'But only this morning he said to me, "It's a nice day Mr Sidney!" Just like that. Normal as anything. Well... normal for Walter...'

'As a matter of fact, it's always worried me, the way his eyes move as though they don't talk to each other–'

'And he's always around the place!'

'Yes, but he's the odd job man–'

'No argument about that!'

'It's not Walter,' said Agnes.

They looked at her.

'That's who he said they're chasing, dear.'

'I don't know who they're chasing, but Walter's not the Ghost. Fancy anyone thinking Walter's the Ghost!' said Agnes, hotly. 'He wouldn't hurt a fly! Anyway, I've seen–'

'He's always struck me as a bit slimy, though.'

'And they say he goes down into the cellars a lot. What for, I ask myself? Let's face it. Fair's fair. He's crazy.'

'He doesn't act crazy!' said Agnes.

'Well, he always looks as though he's about to, you must admit. I'm going to see what's happening. Anyone coming?'

Agnes gave up. It was a horrible thing to learn, but there are times when evidence gets trampled and the hunt is on.

A hatch flew open. The Ghost clambered out, looked down, and slammed the hatch shut. There was a yowl from below.

Then he danced across the leads until he reached the gargoyle-encrusted parapet, black and silver in the moonlight. The wind caught at his cloak as he ran along the very edge of the roof and dropped down again near another door.

And a gargoyle was suddenly no longer a gargoyle, but a figure that reached down suddenly and twitched off his mask.

It was like cutting strings.

'Good evening, Walter,' said Granny, as he sagged to his knees.

'Hello Missus Weatherwax!'

'Mistress,' Granny corrected him. 'Now stand up.' There was a growl further along the roof, and then a thump. Bits of trapdoor rose for a moment against the moonlight.

'It's nice up here, ain't it?' said Granny. 'There's fresh air and stars. I thought: up or down? But there's only rats down below.'

In another swift movement she grabbed Walter's chin and tilted it, just as Greebo pulled himself on to the roof with prolonged murder in his heart.

'How does your mind work, Walter Plinge? If your house was on fire, what's the first thing you'd try to take out?

Greebo stalked along the rooftop, growling. He liked rooftops in general, and some of his fondest memories involved them, but a trapdoor had just been slammed on his head and he was looking for anything he could disembowel.

Then he recognized the shape of Walter Plinge as someone who had given him food. And, standing right next to him, the much more unwelcome shape of Granny Weatherwax, who had once caught him digging in her garden and had kicked him in the cucumbers.

Walter said something. Greebo didn't take much notice of it.

Granny Weatherwax said: 'Well done. A good answer. Greebo!'

Greebo nudged Walter heavily in the back.

'Want milluk right noaow! Purr, purr!'

Granny thrust the mask at the cat. In the distance people were running up stairs and shouting.

'You put this on! And you stay down real low, Walter Plinge. One man in a mask is pretty much like another, after all. And when they chase you, Greebo... give them a run for their money. Do it right and there could be–'

'Yurr, I knoaow,' said Greebo despondently, taking the mask. It was turning out to be a long and busy evening for a kipper.

Someone poked their head out of the stricken trapdoor. The light glinted off Greebo's mask... and it had to be said, even by Granny, that he made a good Ghost. For one thing, his morphogenic field was trying to reassert itself. His claws could no longer even remotely be thought of as fingernails.

He spat at the pursuit as they poured up the steps, arched his back dramatically on the very edge of the roof, and stepped off.

One storey down he thrust out an arm, caught a windowsill, and landed on the head of a gargoyle, which said 'Oh, fank oo ver' mush' in a reproachful voice.

The pursuers looked down at him. Some of them had managed to get hold of flaming torches, because sometimes convention is too strong to be lightly denied.

Greebo snarled defiance and dropped again, springing from sill to drainpipe to balcony and pausing every now and again for another dramatic pose and another snarl at the pursuers.

'We'd better get after him, Corporal de Nobbs,' said one of them, who was staggering along behind.

'We'd better get after him by carefully going back down the stairs, you mean. 'Cos somethin' I drank don't want to stay drunk. Much more runnin' and I'll be droppin' a custard, I'm tellin' you.'

The other members of the posse also seemed to be reaching the conclusion that there was no extended future in chasing a man down the sheer wall of a building. As one mob they turned and, shouting and waving their torches in the air, headed back to the stairs.

The parting crowd revealed Nanny Ogg, holding a pitchfork in one hand and a torch in the other and thrusting them both in the air while muttering, 'Rhubarb, rhubarb.'

Granny walked over and tapped her on the shoulder. 'They've gone, Gytha.'

'Rhuba- Oh, hello, Esme,' said Nanny, lowering the implements of righteous retribution. 'I was just tagging along to see it didn't get out of hand. Was that Greebo I saw just then?'

'Yes.'

'Awww, bless him,' said Nanny. 'He looked a bit bothered, though. I hope he doesn't happen to anybody.'

'Where's your broomstick?' said Granny.

'It's in the cleaners' cupboard backstage.'

'Then I'll borrow it and keep an eye on things,' said Granny.

'Hey, he's my cat, I ought to be looking after him–' Nanny began.

Granny stepped aside, revealing a huddled shape sitting hugging its knees. 'You look after Walter Plinge,' she said. 'It's something you'd be better at than me.'

'Hello Mrs Ogg!' said Walter, mournfully.

Nanny looked at him for a moment.

'So he is the-?'

'Yes.'

'You mean he really did do the mur-?'

'What do you think?' said Granny.

'Well, if it comes to it, I think he didn't,' said Nanny. 'Can I have a word in your ear, Esme? I don't reckon I should say this in front of young Walter.'

The witches bent their heads together. There was a brief whispered conversation.

'Everything is simple when you know the answer,' said Granny. 'I'll be back soon.'

She hurried off. Nanny heard her shoes clattering on the stairs.

Nanny looked down at Walter again, and held out her hand. 'Up you get, Walter.'

'Yes Mrs Ogg!'

'I expect we'd better find somewhere for you to lie low, eh?'

'I know a hidden place Mrs Ogg!'

'You do, do you?'

Walter lurched across the roof towards another trapdoor, and pointed to it proudly.

'That?' said Nanny. 'That doesn't look very hidden to-me, Walter.'

Walter gave it a puzzled look, and then grinned in the way a scientist might after he'd solved a particularly difficult equation. 'It's hidden where everyone can see it Mrs Ogg!'

Nanny gave him a sharp look, but there was nothing but a slightly glazed innocence in Walter's eyes.

He lifted up the trapdoor and pointed politely downwards. 'You go down the ladder first so I will not see your drawers!'

'Very... kind of you,' said Nanny. It was the first time anyone had ever said anything like that to her.

The man waited patiently until she had reached the bottom of the ladder, and then climbed laboriously down after her.

'This is just an old staircase, isn't it?' said Nanny, prodding at the darkness with her torch.

'Yes! It goes all the way down! Except at the bottom where it goes all the way up!'

'Anyone else know about it?'

'The Ghost Mrs Ogg!' said Walter, climbing down.

'Oh, yes,' said Nanny slowly. 'And where's the Ghost now, Walter?'

'He ran away!'

She held up the torch. There was still nothing to be read in Walter's expression. 'What does the Ghost do here, Walter?'

'He watches over the Opera!'

'That's very kind of him, I'm sure.'

Nanny started downwards, and as the shadows danced around her she heard Walter say: 'You know she asked me a very silly question Mrs Ogg! It was a silly question any fool knows the answer!'

'Oh, yes,' said Nanny, peering at the walls. 'About houses on fire, I expect...'

'Yes! What would I take out of our house if it was on fire!'

'I expect you were a good boy and said you'd take your mum,' said Nanny.

'No! My mum would take herself!'

Nanny ran her hands over the nearest wall. Doors had been nailed shut when the staircase had been abandoned. Someone walking up and down here, with a keen pair of ears, could hear a lot of things...

'What would you take out then, Walter?' she said.

'The fire!'

Nanny stared unseeing at the wall, and then her face slowly broke into a grin.

'You're daft, Walter Plinge,' she said.

'Daft as a broom Mrs Ogg!' said Walter cheerfully.

But you ain't insane, she thought. You're daft but you're sane. That's what Esme would say. And there's worser things.

Greebo pounded along Broadway. He was suddenly not feeling very well. Muscles were twitching in odd ways. A tingling at the base of his spine indicated that his tail wanted to grow, and his ears definitely wanted to creep up the sides of his head, which is always embarrassing when it happens in company.

In this case the company was about a hundred yards behind and apparently intent on moving his ears quite a long way from their current position, embarrassment or not.

It was gaining, too. Greebo normally had a famous turn of speed, but not when his knees were trying to reverse direction every few seconds.

His normal plan when pursued was to jump on to the water-butt behind Nanny Ogg's cottage and rake the pursuer across the nose with his claws when it came around the corner. Since this would now involve a fivehundred-mile dash, an alternative had to be sought.

There was a coach waiting outside one of the houses. He lurched over to it, pulled himself up, grabbed the reins and briefly turned his attention to the driver.

'Get orffl.'

Greebo's teeth shone in the moonlight. The coachman, with great presence of mind and urgent absence of body, somersaulted backwards into the night.

The horses reared, and tried to break into a gallop from a standing start. Animals are less capable of being fooled than are humans; they knew that what they had behind them was a very large cat, and the fact that it was manshaped didn't make them any happier.

The coach lumbered off. Greebo looked over his twitching shoulder at the torchlit crowd and waved a paw derisively. The effect pleased him so much that he clambered on to the roof of the swaying coach and continued to jeer.

It is a cat-like attribute to spit defiance at the enemy from a place of safety. In the circumstances it would have been better if cat-like attributes had included the ability to steer.

A wheel hit the parapet of the Brass Bridge and scraped along it, the iron rim kicking up sparks. The shock knocked Greebo from his perch in midgesture. He landed on his feet in the middle of the road, while the terrified horses continued on with the coach rocking dangerously from side to side.

The pursuers stopped.

'What's he doing now?'

'He's just standing there.'

'There's only one of him and there's lots of us, right? We could easily overpower him.'

'Good idea. On the count of three, we'll all rush him, right? One... two... three...'Pause. 'You didn't run.'

'Well, nor did you.'

'Yes, but I was the one saying "one, two, three".'

'Remember what he did to Mr Pounder!'

'Yes, well, I never liked the man all that much...'

Greebo snarled. Ticklish things were happening to his body. He threw his head back and roared.

'Look, at worst he'd only be able to get one or two of us'

'Oh, that's good, is it?'

'Here, why's he twisting around like that?'

'Maybe he hurt himself falling off the coach–'

'Let's get .him!'

The mob closed in. Greebo, struggling against a morphogenic field swinging wildly between species, punched the first man in the face with a hand and clawed the shirt off another man with something more like a giant paw.

'Oh, shiiiooooo–'

Twenty hands grabbed him. And then, in the melee and the darkness, twenty hands were holding just cloth and emptiness. Vengeful boots connected with nothing more than air. Clubs that had been swung at a snarling face whirled through empty space and returned to hit their owner on the ear.

'-ooooaaawwwwl!'

Quite unnoticed in the scrum, a flat-eared bullet of grey fur shot out from between the scuffling legs.

The kicking and punching stopped only when it became apparent that all the mob was attacking was itself. And, since the IQ of a mob is the IQ of its most stupid member divided by the number of mobsters, it was never very clear to anyone what had happened. Obviously they'd closed in on the Ghost, and he certainly couldn't have escaped. All that was left was a mask and some torn clothing. So, the mob reasoned, he must have ended up in the river. And good riddance, too.

Happy in the knowledge of a job well done, they adjourned to the nearest pub.

This left Sergeant Count de Tntus and Corporal the Count de Nobby Nobbs, who lurched to the middle of the bridge and regarded the few scraps of cloth.

'Commander Vimes isn't...isn't... isn't goin' to like dis,' said Detritus. 'You know he likes prisoners to be alive.'

'Yeah, but this one would've been hung anyway,' said Nobby, who was trying to stand upright. 'This way was just a bit more... democratic. A great saving in terms of rope, not to mention wear and tear on locks and keys.'

Detritus scratched his head. 'Shouldn't there be some blood?' he ventured.

Nobby gave him a sour look. 'He couldn't've got away,' he said. 'So don't go asking questions like that.'

'Only, if humans is hit hard enough, they leaks all over der place,' said Detritus.

Nobby sighed. That was the calibre of people you got in the Watch these days. They had to make a mystery of things. In days gone by, when it had been just the old gang and an unofficial policy of lazy fair, they'd have said a heartfelt 'Well done, lads' to the vigilantes and turned in early. But now old Vimes had been promoted to Commander he seemed to be enrolling people who asked questions all the time. It was even affecting Detritus, considered by other trolls to be as dim as a dead glowworm.

Detritus reached down and picked up an eyepatch.

'What d'you think, then?' said Nobby scornfully. 'You think he turned into a bat and flew away?'

'Ha! I do not t'ink that 'cos it is in... consist... ent with modern policing,' said Detritus.

'Well, I think,' said Nobby, 'that when you have ruled out the impossible, what is left, however improbable, ain't worth hanging around on a cold night wonderin' about when you could be getting on the outside of a big drink. Come on. I want to try a leg of the elephant that bit me.'

'Was dat irony?'

'That was metaphor.'

Detritus, uneasy in what was technically his mind, prodded at the torn pieces of clothing.

Something brushed against his leg. It was a cat. It had tattered ears, one good eye, and a face like a fist with fur on it.

'Hello, little cat,' said Detritus.

The cat stretched and grinned. 'Gerrt lorssst, coppuurrrr...'

Detritus blinked. There are no such things as troll cats, and Detritus had never seen a cat before he'd arrived in AnkhMorpork and discovered that they were very, very hard to eat. And he'd never heard of them talking. On the other hand, he was very much aware of his reputation as the most stupid person in the city, and he wasn't going to draw attention to a talking cat if it were going to turn out that everybody except him knew that they talked all the time.

In the gutter, a few feet away, there was something white. He picked it up carefully. It looked like the mask the Ghost had worn.

This was probably a Clue.

He waved it urgently. 'Hey, Nobby–'

'Thank you.' Something dipped through the darkness, snatched the mask from the troll's hand, and soared into the night.

Corporal Nobbs turned around. 'Yes?' he said.

'Er... how big are birds? Normally?'

'Oh, blimey, I dunno. Some are small, some are big. Who cares?'

Detritus sucked his finger. 'Oh, no reason,' he said. 'I am far too smart to be taken in by perfec'ly normal t'ings.'

Something squelched underfoot.

'It's pretty damp down here, Walter,' said Nanny.

And the air was stale and heavy and seemed to be squeezing the light from the torch. There was a dark edge to the flame.

'Not far now Mrs Ogg!'

Keys jingled in the darkness, and some hinges creaked.

'I found this Mrs Ogg! It's the Ghost's secret cave!'

'Secret cave, eh?'

'You got to shut your eyes! You got to shut your eyes!' said Walter urgently.

Nanny did so, but to her shame kept a grip on the torch, just in case. She said: 'And is the Ghost in there, Walter?'

'No!'

There was the rattle of a matchbox and some scuffling, and then

'You can open them now Mrs Ogg!'

Nanny did so.

Colour and light blurred and then swam into focus, first in her eyes and then, eventually, in her brain. 'Oh, my,' she murmured. 'Oh, my, my...'

There were candles, the big flat ones used to illuminate the stage, floating in shallow bowls. The light they gave was soft, and it rippled over the room like the soul of water.

It glinted off the beak of a huge swan. It glittered in the eye of a vast, sagging dragon.

Nanny Ogg turned slowly. Her experience of opera had not been a lengthy one but witches pick things up quickly, and there was the winged helmet worn by Hildabrun in The Ring of the Nibelungingung, and here was the striped pole from The Barber of Pseudopolis, and there was the pantomime horse with the humorous trapdoor from The Enchanted Piccolo, and here...

...here was opera, all piled in a heap. Once the eye had taken it all in, it had time to notice the peeling paint and rotting plaster and the general air of gentle mouldering. The decrepit props and threadbare costumes had been dumped in here because people didn't want them anywhere else.

But someone did want them here. After the eye had seen the ruin, then there was time for it to see the little patches of recent repair, the careful areas of fresh paint.

There was something like a desk in the tiny area of floor not occupied by the props. And then Nanny realized that it had a keyboard and a stool, and there were neat piles of paper on top of it.

Walter was watching her with a big, proud grin.

Nanny ambled over to the thing. 'It's a harmonium, ain't it? A tiny organ?'

'That's right Mrs Ogg!'

Nanny picked up one of the sheaves of paper. Her lips moved as she read the meticulous copperplate writing.

'An opera about cats?' she said. 'Never heard of an opera about cats...'

She thought for a moment, and then added to herself But why not? It's a damn good idea. The lives of cats are just like operas, when you come to think about it.

She leafed through the other piles. 'Guys and Trolls? Hubwards Side Story? Miserable Les? Who's he? Seven Dwarfs for Seven Other Dwarfs? What're all these, Walter?'

She sat down on the stool and pressed a few of the cracked yellow keys, which moved with an audible creak. There were a couple of large pedals under the harmonium. You pedalled these and that worked the bellows and these spongy keys produced something which was to organ music what 'poot' was to cursing.

So this was where Wal... where the Ghost sat, thought Nanny, down under the stage, among the discarded wreckage of old performances; down under the huge windowless room where, night after night, music and songs and rampant emotion echoed back and forth and never escaped or entirely died away. The Ghost worked down here, with a mind as open as a well, and it filled up with opera. Opera went in at the ears, and something else came out of the mind.

Nanny pumped the pedals a few times. Air hissed from inefficient seams. She tried a few notes. They were reedy. But, she considered, sometimes the old lie was true, and size really did not matter. It really was what you did with it that counted.

Walter watched her expectantly.

She took down another wad of paper and peered at the first page. But Walter leaned over and snatched at the script.

'That one's not finished Mrs Ogg!'

The Opera House was still in uproar. Half the audience had gone outside and the other half was hanging around in case further interesting events were going to transpire. The orchestra was in a huddle in the pit, preparing its request for a special Being Upset By A Ghost Allowance. The curtains were closed. Some of the chorus had stayed on stage; others had hurried off to take part in the chase. The air had the excited electric feel it gets when normal civilized life is temporarily short-circuited.

Agnes bounced frantically from rumour to rumour. The Ghost had been caught, and it was Walter Plinge. The Ghost had been caught by Walter Plinge. The Ghost had been caught by someone else. The Ghost had escaped. The Ghost was dead.

There were arguments breaking out everywhere.

'I still can't believe it was Walter! I mean, good grief... Walter?'

'What about the show? We can't just stop! You never stop the show, not even if someone dies!'

'Oh, we have stopped when people died...'

'Yes, but only as long as it took to get the body off-stage!'

Agnes stepped back into the wings, and trod on something. 'Sorry,' she said automatically.

'It was only my foot,' said Granny Weatherwax. 'So... how is life in the big city, Agnes Nitt?'

Agnes turned. 'Oh... hello, Granny...' she mumbled. 'And I'm not Agnes here, thank you,' she added, a shade more defiantly.

'It's a good job, is it, bein' someone else's voice?'

'I'm doing what I want to do,' said Agnes. She drew herself up to her full width. 'And you can't stop me!'

'But you ain't part of it, are you?' said Granny conversationally. 'You try, but you always find yourself watchin' yourself watchin' people, eh? Never quite believin' anything? Thinkin' the wrong thoughts?'

'Shut up!'

'Ah. Thought so.'

'I have no intention of becoming a witch, thank you very much!'

'Now, don't go getting upset just because you know it's going to happen. A witch you're going to be because a witch you are, and if you turn your back on him now then I don't know what's going to happen to Walter Plinge.'

'He's not dead?'

No.

Agnes hesitated. 'I knew he was the Ghost,' she began. 'But then I saw he couldn't be.'

'Ah,' said Granny. 'Believed the evidence of your own eyes, did you? In a place like this?'

'One of the stage-hands just told me they chased him up on to the roof and then down into the street and beat him to death!'

'Oh, well,' said Granny, 'you'll never get anywhere if you believe what you hear. What do you know?'

'What do you mean, what do I know?'

'Don't try cleverness on me, miss.'

Agnes looked at Granny's expression, and knew when to fold. 'I know he's the Ghost,' she said.

'Right.'

'But I can see that he isn't.'

'Yes?'

'And I know... I'm pretty sure he doesn't mean any harm.'

'Good. Well done. Walter might not know his right from his left, but he does know his right from his wrong.' Granny rubbed her hands together. 'Well, we're already home and looking for a clean towel, eh?'

'What? You haven't solved anything!'

' 'Course we have. We know that it wasn't Walter what done the murders, so now we just have to find out who it was. Easy.'

'Where's Walter now?'

'Nanny's got him somewhere.'

'She's all by herself?'

'I told you, she's got Walter.'

'I meant... well, he's a bit strange.'

'Only where it shows.'

Agnes sighed, and started to say that it wasn't her problem. And realized it was useless even to try. The knowledge sat like a smug intruder in her mind. Whatever it was, it was her problem.

'All right,' she said. 'I'll help you if I can, because I'm here. But afterwards... that's it! Afterwards, you'll leave me alone. Promise?'

'Certainly.'

'Well... all right, then...' Agnes stopped. 'Oh, no,' she said. 'That was too easy. I don't trust you.'

'Don't trust me?' said Granny. 'You're saying you don't trust me?'

'Yes. I don't. You'll find a way to wriggle around it.'

'I never wriggle,' said Granny. 'It's Nanny Ogg who thinks we ought to have a third witch. I reckon life's difficult enough without some girl cluttering up the place just because she thinks she looks good in a pointy hat.'

There was a pause. Then Agnes said, 'I'm not falling for that one, either. It's where you say I'm too stupid to be a witch and I say, oh no I'm not, and you end up winning again. I'd rather be someone else's voice than some old witch with no friends and having everyone frightened of me and being nothing more than just a bit cleverer than other people and not doing any real magic at all...'

Granny put her head on one side.

'Seems to me you're so sharp you might cut yourself,' she said. 'All right. When it's all over, I'll let you go your own way. I won't stop you. Now show me the way to Mr Bucket's office...'

Nanny smiled her jolly-wrinkled-old-apple smile. 'Now, you just hand it over, Walter,' she said. 'No harm in letting me see it, is there? Not old Nanny.'

'Can't see it till it's finished!'

'Well, now,' said Nanny, hating herself for dropping the atom bomb, 'I'm sure your main wouldn't want to hear that you've been a bad boy, would she?'

Expressions floated over Walter's waxen features as he struggled with several ideas at once. Finally, without a word, he thrust the bundle at her, his arms trembling with tension.

'There's a good boy,' said Nanny.

She glanced at the first few pages, and then moved them nearer to the light. 'Hmm.'

She treadled the harmonium for a while and played a few notes with her left hand. They represented most of the musical notes she knew how to read. It was a very simple little theme, such as might be picked out on the keyboard with one finger. 'Hey...'

Her lips moved as she read the narrative.

'Well now, Walter,' she said, 'isn't this a sort of opera about a ghost who lives in an opera house?' She turned a page. 'Very smart and debonair, he is. He's got a secret cave, I see...'

She played another short riff. 'Catchy music, too.'

She read on, occasionally saying things like 'Well, well' and 'Lawks'. Every now and again she'd give Walter an appraising look.

'I wonder why the Ghost wrote this, Walter?' she said, after a while. 'Quiet sort of chap, ain't he? Put it all into his music.'

Walter stared at his feet. 'There's going to be a lot of trouble Mrs Ogg.'

'Oh, me and Granny will sort it all out,' said Nanny.

'It's wrong to tell lies,' said Walter.

'Probably,' said Nanny, who'd never let it worry her up to now.

'It wouldn't be right for our mum to lose her job Mrs Ogg.'

'It wouldn't be right, no.'

The feeling drifted over Nanny that Walter was trying to put across some sort of message. 'Er... what sort of lies would it be wrong to tell, Walter?'

Walter's eyes bulged. 'Lies... about things you see Mrs Ogg! Even if you did see them!'

Nanny thought it was probably time to present the Oggish point of view. 'It's all right to tell lies if you don't think lies,' she said.

'He said our mum would lose her job and I'd be locked up if I said Mrs Ogg!'

'Did he? Which "he" was he?'

'The Ghost Mrs Ogg!'

'I reckon Granny ought to have a good look at you, Walter,' said Nanny. 'I reckon your mind's all tangled up like a ball of string what's been dropped.' She pedalled the harmonium thoughtfully. 'Was it the Ghost that wrote all this music, Walter?'

'It's wrong to tell lies about the room with the sacks in it Mrs Ogg!'

Ah, thought Nanny. 'That'd be down here, would it?'

'He said I wasn't to tell anyone!'

'Who did?'

'The Ghost Mrs Ogg!'

'But you're–' Nanny began, and then tried another way. 'Ah, but I ain't anyone,' she said. 'Anyway, if you was to go to this room with the sacks and I was to follow you, that wouldn't be telling anyone, would it? It wouldn't be your fault if some ole woman followed you, would it?'

Walter's face was an agony of indecision but, erratic though his thinking might have been, it was no match for Nanny Ogg's meretricious duplicity. He was up against a mind that regarded truth as a reference point but certainly not as a shackle. Nanny Ogg could think her way through a corkscrew in a tornado without touching the sides.

'Anyway, it's all right if it's me,' she added for good measure. 'In fact, he prob'ly meant to say "except for Mrs Ogg", only he forgot.'

Slowly, Walter reached out and picked up a candle. Without saying a word he walked out of the door and into the damp darkness of the cellars.

Nanny Ogg followed him, her boots making squelching noises in the mud.

It didn't seem like much of a distance. As far as Nanny could work out they were no longer under the Opera House, but it was hard to be sure. Their shadows danced around them and they walked through other rooms, even more dark and dripping than the ones they'd been in. Walter stopped in front of a pile of timber that glistened with rot, and pulled a few of the spongy planks aside.

There were some sacks neatly piled.

Nanny kicked one, and it broke.

In the flickering candlelight all that she could really see were sparkles of light as the cascade poured out, but there was no mistaking the gentle metallic scraping of lots of money. Lots and lots of money. Enough money to suggest very clearly that it belonged to either a thief or a publisher, and there didn't seem to be any books around.

'What's this, Walter?'

'It's the Ghost's money Mrs Ogg!'

There was a square hole in the opposite corner of the room. Water glinted a few inches below. Beside the hole were half a dozen containers of various sorts–old biscuit tins, broken bowls and the like. There was a stick, or possibly a dead shrub, in each one.

'And those, Walter? What are those?'

'Rose bushes Mrs Ogg!'

'Down here? But nothing could gr–'

Nanny stopped.

She squelched over to the pots. They'd been filled with muck scraped from the floor. The dead stems glistened with slime.

Nothing could grow down here, of course. There was no light. Everything that grew needed something else to feed on. And...she moved the candle closer, and sniffed the fragrance. Yes. It was subtle, but it was there. Roses in darkness.

'Well, my word, Walter Plinge,' she said. 'Always one for the surprises, you are.'

Books were piled on Mr Bucket's desk.

'What you're doing is wrong, Granny Weatherwax,' said Agnes from the doorway.

Granny glanced up. 'Wrong as living other people's lives for them?' she said. 'S' matter of fact, there's something even worse than that, which is living other people's lives for yourself. That kind of wrong?'

Agnes said nothing. Granny Weatherwax couldn't know.

Granny turned back to the books. 'Anyway, this only looks wrong. Appearances is deceivin'. You just pay attention to watching the corridor, madam.'

She riffled through the bits of torn envelope and scribbled notes that seemed to be the Opera House's equivalent of proper accounts. It was a mess. In fact, it was more than a mess. It was far too much of a mess to be. a real mess, because a real mess has occasional bits of coherence, bits of what might be called random order. Rather, it was the kind of erratic mess that suggested that someone had set out to be messy.

Take the account books. They were full of tiny rows and columns, but someone hadn't thought it worthwhile to invest in lined paper and had handwriting that wandered a bit. There were forty rows on the left-hand side but only thirty-six by the time they reached the other side of the page. It was hard to spot because of the way your eyes watered.

'What are you doing?' said Agnes, tearing her gaze away from the corridor.

'Amazin',' said Granny. 'Some things is entered twice! And I reckon there's a page here where someone's added the month and taken away the time of day!'

'I thought you didn't like books,' said Agnes.

'I don't,' said Granny, turning a page. 'They can look you right in the face and still lie. How many fiddle players are there in the band?'

'I think there are nine violinists in the orchestra.'

The correction appeared to pass unnoticed.

'Well, there's a thing,' said Granny, without moving her head. 'Seems that twelve of 'em are drawing wages, but three of 'em is over the page, so you mightn't notice.' She looked up and rubbed her hands happily. 'Unless you've got a good memory, that is.'

She ran a skinny finger down another erratic column. 'What's a flying ratchet?'

'I don't know!'

'Says here "Repairs to flying ratchet, new springs for rotation cog assembly, and making good. Hundred and sixty dollars and sixty-three pence." Hah!'

She licked her finger and tried another page –

'Even Nanny ain't this bad at numbers,' she said. 'To be this bad at numbers you've got to be good. Hah! No wonder this place never makes any money. You might as well try to fill a sieve.'

Agnes darted into the room. 'There's someone coming!'

Granny got up and blew out the lamp. 'You get behind the curtains,' she commanded.

'What're you going to do?'

'Oh... I'll just have to make myself inconspicuous...'

Agnes hurried across to the big window and turned to look at Granny, who was standing by the fireplace.

The old witch faded. She didn't disappear. She merely slid into the background.

An arm gradually became part of the mantelpiece. A fold of her dress was a piece of shadow. An elbow became the top of the chair behind her. Her face became one with a vase of faded flowers.

She was still there, like the old woman in the puzzle picture they sometimes printed in the Almanack, where you could see the old woman or the young girl but not both at once, because one was made of the shadows of the other. Granny Weatherwax was standing by the fireplace, but you could see her only if you knew she was there.

Agnes blinked. And there were just the shadows, the chair and the fire.

The door opened. She ducked behind the curtains, feeling as conspicuous as a strawberry in a stew, certain that the sound of her heart would give her away.

The door shut, carefully, with barely a click. Footsteps crossed the floor. A wooden scraping noise might have been a chair being moved slightly.

A scratch and a hiss were the sound of a match, striking. A clink was the glass of the lamp, being lifted...

All noise ceased.

Agnes crouched, every muscle suddenly screaming with the strain. The lamp hadn't been lit–she'd have seen the light around the curtain.

Someone out there was making no noise.

Someone out there was suddenly suspicious.

A floorboard squeaked verrrry slowwwly, as someone shifted their weight.

She felt as if she was going to scream, or burst with the effort of silence. The handle of the window behind her, a mere point of pressure a moment ago, was trying seriously to become part of her life. Her mouth was so dry that she knew it'd creak like a hinge if she dared to swallow.

It couldn't be anyone who had a right to be here. People who had a right to be in places walked around noisily.

The handle was getting really personal.

Try to think of something else...

The curtain moved. Someone was standing on the other side of it.

If her throat weren't so arid she might be able to scream.

She could feel the presence through the cloth. Any moment now, someone was going to twitch the curtain aside.

She leapt, or as close to a leap as was feasible–it was a kind of vertical lumber, billowing the curtain aside, colliding with a slim body behind it, and ending on the floor in a tangle of limbs and ripping velvet.

She gulped air, and pressed down on the squirming bundle below her.

'I'll scream!' she said. 'And if I do your eardrums will come down your nose!'

The writhing stopped.

'Perdifa?' said a muffled voice.

Above her, the curtain-rail sagged at one end and the brass rings, one at a time, spun towards the floor.

Nanny went back to the sacks. Each one bulged with round hard shapes that clinked gently under her questing finger.

'This is a lot of money, Walter,' she said carefully.

'Yes Mrs Ogg!'

Nanny lost track of money fairly easily although this didn't mean the subject didn't interest her: it was just that, beyond a certain point, it became dream-like. All she could be sure of was that the amount in front of her would make anyone's drawers drop.

'I suppose,' she said, 'that if I was to ask you how it'd got here, you'd say it was the Ghost, yes? Like the roses?'

'Yes Mrs Ogg!'

She gave him a worried look. 'You'll be all right down here, will you?' she said. 'You'll sit quiet? I reckon I need to talk to some people.'

'Where's my mum Mrs Ogg?'

'She's having a nice sleep, Walter.'

Walter seemed satisfied with this.

'You'll sit quiet in your... in that room, will you?'

'Yes Mrs Ogg!'

'There's a good boy.'

She glanced at the money-bags again. Money was trouble.

Agnes sat back.

André raised himself on his elbows and pulled the curtain off his face. 'What the hell were you doing there?' he said.

'I was- What do you mean, what was I doing there? You were creeping around!'

'You were hiding behind the curtain!' said André, getting to his feet and fumbling for the matches again. 'Next time you blow out a lamp, remember it'll still be warm.'

'We were... on important business...'

The lamp glowed. André turned. 'We?' he said.

Agnes nodded, and looked across at Granny. The witch hadn't moved, although it took a deliberate effort of will to focus on her among the shapes and shadows.

André picked up the lamp and stepped forward.

The shadows shifted.

'Well?' he said.

Agnes strode across the room and waved a hand in the air. There was the chair back, there was the vase, there was... nothing else.

'But she was there!'

'A ghost, eh?' said André sarcastically.

Agnes backed away.

There is something about the light of a lamp held lower than someone's face. The shadows are wrong. They fall into unfortunate places. Teeth seem more prominent. Agnes came to realize that she was alone in a room in suspicious circumstances with a man whose face suddenly looked a lot more unpleasant than it had before.

'I suggest,' he said, 'that you get back to the stage right now, yes? That would be the very best thing you could do. And don't meddle in things that don't concern you. You've done too much as it is.'

The fear hadn't drained out of Agnes, but it had found a space in which to metamorphose into anger.

'I don't have to put up with that! For all I know, you might be the Ghost!'

'Really? I was told that Walter Plinge was the Ghost,' said André. 'How many people did you tell? And now it turns out that he's dead...'

'No, he's not!'

It was out before she could stop it. She'd said it merely to wipe the sneer off his face. This happened. But the expression that replaced it was no improvement.

A floorboard creaked.

They both turned.

There was a hat-stand in the corner, next to a bookcase. There were a few coats and scarves hanging from it. It was surely only the way that the shadows fell that made it look, from this angle, like an old woman. Or. . .

'Damn floors,' said Granny, fading into the foreground. She stepped away from the coats.

As Agnes said, later: it wasn't as though she'd been invisible. She'd simply become part of the scenery until she put herself forward again; she was there, but not there. She didn't stand out at all. She was as unnoticeable as the very best of butlers.

'How did you get in?' said André. 'I looked all round the room!'

'Seein' is believin',' said Granny, calmly. 'Of course, the trouble is that believin' is also seein', and there's been too much of that round here lately. Now, I know you ain't the Ghost... so what are you, to be sneaking around in places where you shouldn't be?'

'I could ask you the same quest–'

'Me? I'm a witch, and I'm pretty good at it.'

'She's, er, from Lancre. Where I come from,' Agnes mumbled, trying to look at her feet.

'Oh? Not the one who wrote the book?' said André. 'I've heard people talking about–'

'No! I'm much worse than her, understand?'

'She is,' mumbled Agnes.

André gave Granny a long look, like a man weighing up his chances. He must have decided that they were bobbing along the ceiling.

'I... hang around in dark places looking for trouble,' he said.

'Really? There's a nasty name for people like that, ' snapped Granny.

'Yes,' said André. 'It's "policeman".'

Nanny Ogg climbed out of the cellars, rubbing her chin thoughtfully. Musicians and singers were still milling around, uncertain about what was going to happen next. The Ghost had had the decency to be chased and killed during the interval. In theory that meant there was no reason why there shouldn't be a third act, as soon as Herr Trubelmacher had scoured the nearby pubs and dragged the orchestra back. The show must go on.

Yes, she thought, it has to go on. It's like the build-up to a thunderstorm... no... it's more like making love. Yes. That was a far more Oggish metaphor. You put everything you've got into it, so sooner or later there's a point where it's got to go on, because you can't imagine stopping. The stage manager could dock a couple of dollars from their wages and they'd still go on, and everyone knew it. And they would still go on.

She reached a ladder and climbed slowly into the flies.

She hadn't been certain. She needed to be certain now.

The fly loft was empty. She walked carefully along the catwalk until she was over the auditorium. The buzz of the audience came through the ceiling beneath her, slightly muffled.

Light shone up at the point where the thick cable for the chandelier disappeared into the hole. She stepped out over the creaking trapdoor and peered down.

Terrific heat almost frizzled her hair. A few yards below her hundreds of candles were burning.

'Dreadful if that lot fell down,' she said quietly. 'I 'spect this place'd go up like a haystack...'

She let her gaze travel up and up .the cable to the point, at just about waist-height, where it was halfcut through. You'd never see it, if you weren't expecting to find it.

Then her gaze dropped again, and moved across the gloomy, dusty floor until it found something half-hidden in the dust:

Behind her, a shadow among the shadows rose to its feet, balanced itself carefully, and started to run.

'I knows about policemen,' said Granny. 'They've got big helmets and big feet and you can see them a mile off. There's a couple lurching around backstage. Anyone can see they're policemen. You don't look like one.' She turned the badge over and over in her hands. 'I ain't happy with the idea of secret policemen,' she said. 'Why do you need secret policemen?'

'Because,' said André, 'sometimes you have secret criminals.'

Granny almost smiled. 'That's a fact,' she said. She peered at the small engraving on the back of the badge. 'Says here "Cable Street Particulars"...'

'There aren't many of us,' said André. 'We've only just started. Commander Vimes said that, since we can't do anything about the Thieves' Guild and the Assassins' Guild, we'd better look for other crimes. Hidden crimes. That need Watchmen with... different skills. And I can play the piano quite well...,

'What kind of skills have that troll and that dwarf got?' said Granny. 'Seems to me the only thing they're really good at is standing around looking obvious and stupiHah! Yes...'

'Right. And they didn't even need much training,' said André. 'Commander Vimes says they're the most obvious policemen anyone could think of. Incidentally, Corporal Nobbs has got some papers to prove he's a human being.'

'Forged?'

'I don't think so.'

Granny Weatherwax put her head on one side. 'If your house was on fire, what's the first thing you'd take out of it?'

'Oh, Granny–' Agnes began.

'Hmm. Who set fire to it?' said André.

'You're a policeman, right enough.' Granny handed him his badge. 'You come to arrest poor Walter?' she said.

'I know he didn't murder Dr Undershaft. I was watching him. He was trying to unblock the privies all afternoon–'

'I've had proof that Walter isn't the Ghost,' said Agnes.

'I was almost sure it was Salzella,' said André. 'I know he creeps off to the cellars sometimes and I'm sure he's stealing money. But the Ghost has been seen when Salzella is perfectly visible. So now I think–'

'Think? Think?' said Granny. 'Someone thinking around here at last? How'd you recognize the Ghost, Mister Policeman?'

'Well... he's got a mask on...'

'Really? Now say it again, and listen to what you say. Good grief! You can recognize him because he's got a mask on? You recognize him because you don't know who he is? Life isn't neat! Whoever said there's only one Ghost?'

The figure ran through the shadows of the fly loft, cloak billowing around it. Nanny Ogg was outlined against the light, peering down.

She said, without turning her head: 'Hello, Mr Ghost. Come back for your saw, have you?'

Then she darted around behind the cable until she faced the shadow. 'Millions of people knows I'm up here! You wouldn't hurt a little old lady, would you? Oh, dear... me poor old heart!'

She keeled over backwards, hitting the floor hard enough to make the cable swing.

The figure hesitated. Then it took a length of thin rope from a pocket and advanced cautiously towards the fallen witch. It knelt down, wound an end of the rope around each hand, and leaned forward. ,

Nanny's knee came up sharply.

'Feels a lot -better now, mister,' she said, as he reared backwards.

She scrambled up again and grabbed the saw.

'Come back to finish it, eh?' she said, waving the implement in the air. 'Wonder how you'd blame that on Walter! Make you happy, would it, the whole place burning down?'

The figure, moving awkwardly, backed away as she advanced. Then it turned, lurched along the wobbling catwalk and disappeared into the gloom.

Nanny pounded after him and saw the figure climbing down a ladder. She looked around quickly, grabbed a rope to slide after him, and heard a pulley somewhere above start to clatter.

She descended, skirts billowing around her. When she was about halfway down, a bunch of sandbags went upwards past her in a hurry.

As she rattled onwards she saw, between her boots, someone struggling with the trapdoor to the cellars.

She landed a few feet away, still holding the rope.

'Mr Salzella?'

Nanny stuck two fingers in her mouth and let out a whistle that could have melted ear-wax.

She let go of the rope.

Salzella glanced up at her as he raised the trapdoor, and then saw the shape dropping out of the roof.

One hundred and eighty pounds of sandbag hit the door, slamming it shut.

'Watch out!' said Nanny, cheerfully.

Bucket waited nervously in the wings. Unnecessarily nervously, of course. The Ghost was dead. There couldn't be anything to worry about. People said they'd seen him killed, although they were, Bucket had to admit, a bit hazy on the actual details.

Nothing to worry about.

Not a thing.

Nothing whatsoever in any way.

Everything was absolutely nothing to worry about in any way.

He ran a finger around the inside of his collar. It hadn't been such a bad life in wholesale cheese. The most you had to worry about was ogle of poor old Reg Plenty's trouser buttons in the Farmhouse Nutty and the time young Weevins minced his thumb in the stirring machine and it was only by luck they happened to be doing strawberry yoghurt at the time–

A figure loomed up beside him. He clutched at a curtain for support and then turned to see, with relief, the majestic and reassuring stomach of Enrico Basilica. The tenor looked magnificent in a huge cockerel costume, complete with giant beak, wattles and comb.

'Ah, senor,' Bucket burbled. 'Very impressive, may I say.'

'Si,' said a muffed voice from somewhere behind the beak, as other members of the company hurried past on to the stage.

'May I say how sorry I am about all that business earlier. I can assure you that it doesn't happen every night, ahahah...'

'Si?'

'Probably just high spirits, ahaha...'

The beak turned towards him. Bucket backed away.

'Si!'

'...yes... well, I'm glad you're so understanding...'

Temperamental, he thought, as the tenor strode on to the stage and the overture to Act Three drifted to its close. They're like that, the real artistes. Nerves stretched like rubber bands, I expect. It's just like waiting for the cheese, really. You can get really edgy waiting to see whether you've got half a ton of best blue-vein or just a vat full of pig food. It's probably like that when you've got an aria working its way up–

'Where'd he go? Where'd he go?'

'What? Oh... Mrs Ogg. . .'

The old woman waved a saw in front of his face. It was not, in Mr Bucket's current state of mental tension, a helpful gesture.

He was suddenly surrounded by other figures, equally conducive to multiple exclamation marks.

'Perdita? Why aren't you on stage... oh, Lady Esmerelda, I didn't see you there, of course if you want to come backstage you only have to–'

'Where's Salzella?' said André.

Bucket looked around vaguely. 'He was here a few minutes ago... That is,' he said, pulling himself together, 'Mr Salzella is probably attending to his duties somewhere which, young man, is more than I can say for–'

'I demand you stop the show now,' said André.

'Oh, you do, do you? And by what authority, may I ask?'

'He's been sawing through the rope!' said Nanny.

André pulled out a badge. 'This!'

Bucket looked closely. ' "Ankh-Morpork Guild of Musicians member z 244"?'

André glared at him, then at the badge, and started to pat his pockets urgently. 'No! Blast, I know I had the other one a moment ago... Look, you've got to clear the theatre, we've got to search it, and that means–'

'Don't stop the show,' said Granny.

'I won't stop the show,' said Bucket.

' 'Cos I reckon he'd like to see the show stopped. The show must go on, eh? Isn't that what you believe? Could he have got out of the building?'

'I sent Corporal Nobbs to the stage-door and Sergeant Detritus is in the foyer,' said André. 'When it comes to standing in doorways, they're among the best.'

'Excuse me, what's happening?' said Bucket.

'He could be anywhere!' said Agnes. 'There're hundreds of hiding-places!'

'Who?' said Bucket.

'How about these cellars everyone talks about?' said Granny.

'Where?'

'There's only one entrance,' said André. 'He's not stupid.'

'He can't get into the cellars,' said Nanny. 'He ran off? Probably in a cupboard somewhere by now!'

'No, he'll stay where there's crowds,' said Granny. 'That's what I'd do.'

'What?' said Bucket.

'Could he have got into the audience from here?' said Nanny.

'Who?' said Bucket.

Granny jerked a thumb towards the stage. 'He's somewhere on there. I can feel him.'

'Then we'll wait until he comes off!'

'Eighty people coming off stage all at once?' said Agnes. 'Don't you know what it's like when the curtain goes down?'

'And we don't want to stop the show,' Granny mused.

'No, we don't want to stop the show,' said Bucket, grasping at a familiar idea as it swept by on a tide of incomprehensibility. 'Or give people their money back in any fashion whatsoever. What are we talking about, does anyone know?'

'The show must go on. . .' murmured Granny Weatherwax, still staring out of the wings. 'Things have to end right. This is an opera house. They should end... operatically...'

Nanny Ogg hopped up and down excitedly. 'Oo, I know what you're thinking, Esme!' she squeaked. 'Oo, yes! Can we? Just so's I can say I done it! Eh? Can we? Go on! Let's!'

Henry Lawsy peered closely at his opera notes. He had not, of course, fully understood the events of the first two acts, but knew that this was perfectly OK because one would have to be quite naive to expect good sense as well as good songs. Anyway, it would all be explained in the last act, which was the Masked Ball in the Duke's Palace. It would almost certainly turn out that the woman one of the men had been rather daringly courting would be his own wife, but so cunningly disguised by a very small mask that her husband wouldn't have spotted that she wore the same clothes and had the same hairstyle. Someone's serving man would turn out to be someone else's daughter in disguise; someone would die of something that didn't prevent them from singing about it for several minutes; and the plot would be resolved by some coincidences which, in real life, would be as likely as a cardboard hammer.

He didn't know any of this for a fact. He was making a calculated guess.

In the meantime Act Three opened with the traditional ballet, this time apparently a country dance by the Maidens of the Court.

Henry was aware of muffled laughter around him.

This was because, if you ran an eye at head-height along the row of ballerinas as they tripped, arm in arm, on to the stage, there was an apparent gap.

This was only filled if the gaze went downwards a foot or two, to a small fat ballerina in a huge grin, an overstretched tutu, long white drawers and... boots.

Henry stared. They were big boots. They moved back and forth at an astonishing speed. The satin slippers of the other dancers twinkled as they drifted across the floor, but the boots flashed and clattered like a tap dancer afraid of falling into the sink.

The pirouettes were novel, too. While the other dancers whirled like snowflakes, the little fat one spun like a top and moved across the floor like one too, bits of her anatomy trying to achieve local orbit.

Around Henry members of the audience were whispering to one another.

'Oh yes,' he heard someone declare, 'they tried this in Pseudopolis...'

His mother nudged him. 'This supposed to happen?'

'Er... I don't think so...'

' 'S bloody good, though! A good laugh!'

As the fat ballerina collided with a donkey in evening dress she staggered and grabbed at his mask, which came off...

Herr Trubelmacher, the conductor, froze in horror and astonishment. Around him the orchestra rattled to a standstill, except for the tuba player

-oom-BAH-oom-BAH-oom-BAH–

-who had memorized his score years ago and never took much interest in current affairs.

Two figures rose up right in front of Trubelmacher. A hand grabbed his baton.

'Sorry, sir,' said André, 'but the show must go on, yes?' He handed the stick to the other figure.

'There you are,' he said. 'And don't let them stop.'

'Ook!'

The Librarian carefully lifted Herr Trubelmacher aside with one hand, licked the baton thoughtfully, and then focused his gaze on the tuba player.

-oom-BAH-oom-BAHhhh... oom... om...

The tuba player tapped a trombonist on the shoulder.

'hey, Frank, there's a monkey where old troublemaker should be–'

'shutupshutupshutup!'

Satisfied, the orang-utan raised his arms.

The orchestra looked up. And then looked up a bit more. No conductor in musical history, not even the one who once fried and ate the piccolo-player's liver on a cymbal for one wrong note too many, not even the one who skewered three troublesome violinists on his baton, not even the one who made really hurtful sarcastic remarks in a loud voice, was ever the focus of such reverential attention.

On stage, Nanny Ogg took advantage of the hush to pull the head off a frog.

'Madam!'

'Sorry, thought you might be someone else...'

The long arms dropped. The orchestra, in one huge muddled chord, slammed back into life.

The dancers, after a moment's confusion during which Nanny Ogg took the opportunity to decapitate a clown and a phoenix, tried to continue.

The chorus watched in bemusement.

Christine felt a tap on her shoulder, and turned to see Agnes. 'Perdita! Where have you been!?' she hissed. 'It's nearly time for my duet with Enrico!'

'You've got to help!' hissed Agnes. But down in her soul Perdita said: Enrico, eh? It's Senor Basilica to everyone else...

'Help you what!?' said Christine.

'Take everyone's masks off!'

Christine's forehead wrinkled beautifully. 'That's not supposed to happen until the end of the opera, is it?'

'Er... it's all been changed!' said Agnes urgently. She turned to a nobleman in a zebra mask and tugged it desperately. The singer underneath glared at her.

'Sorry!' she whispered. 'I thought you were someone else!'

'We're not supposed to take them off until the end!'

'It's been changed!'

'Has it? No one told me!'

A short-necked giraffe next to him leaned sideways. 'What's that?'

'The big unmasking scene is now, apparently!'

'No one told me!'

'Yes, but when does anyone ever tell us anything? We're only the chorus... here, why is old Troublemaker wearing a monkey mask... ?'

Nanny Ogg pirouetted past, cannoned into an elephant in evening dress and beheaded him by the trunk. She whispered: 'We're looking for the Ghost, see?'

'But... the Ghost is dead, isn't he?'

'Hard things to kill, ghosts,' said Nanny.

The whisper spread outwards from that point. There is nothing like a chorus for rumour. People who would not believe a High Priest if he said the sky was blue, and was able to produce signed affidavits to this effect from his white-haired old mother and three Vestal virgins, would trust just about anything whispered darkly behind their hand by a complete stranger in a pub.

A cockatoo spun around and pulled the mask off a parrot...

Bucket sobbed. This was worse than the day the buttermilk exploded. This was worse than the flash heatwave that had led a whole warehouseful of Lancre Extra Strong to riot.

The opera had turned into a pantomime.

The audience was laughing.

About the only character still with a mask on was Senor Basilica, who was watching the struggling chorus with as much aloof amazement as his own mask could convey -and this, amazingly enough, was quite a lot.

'Oh, no...' moaned Bucket. 'We'll never live it down! He'll never come back! It'll be all over the opera circuit and no one will ever want to come here ever again!'

'Ever again wha'?' mumbled a voice behind him.

Bucket turned. 'Oh, Senor Basilica,' he said. 'Didn't see you there... I was just thinking, I do hope you don't think this is typical!'

Senor Basilica stared through him, swaying slightly from side to side. He was wearing a torn shirt.

'Summon. . .' he said.

'I'm sorry?'

'Summon... summon hit me onna head,' said the tenor. 'Wanna glassa water pliss...'

'But you're... just about... to... sing... aren't you?' said Bucket. He grabbed the stunned man by the collar to pull him closer, but this simply meant that he dragged himself off the floor, bringing his shoes about level with Basilica's knees. 'Tell me... you're out there... on the stage... please!!!'

Even in his stunned state, Enrico Basilica a.k.a. Henry Slugg recognized what might be called the essential dichotomy of the statement. He stuck to what he knew.

'Summon bashed me inna corridor...' he volunteered.

'That's not you out there?'

Basilica blinked heavily. "M not me?'

'You're going to sing the famous duet in a moment!!!'

Another thought staggered through Basilica's abused skull. "M I?' he said. "S good... 'll look forwa' to that. Ne'er had a chance to hear me befo'...'

He gave a happy little sigh and fell full-length backwards.

Bucket leaned against a pillar for support. Then his brow furrowed and, in the best traditions of the extended double-take, he stared at the fallen tenor and counted to one on his fingers. Then he turned towards the stage and counted to two.

He could feel a fourth exclamation mark coming on any time now.

The Enrico Basilica on stage turned his mask this way and that. Stage right, Bucket was whispering to a group of stage-hands. Stage left, André the secret pianist was waiting. A large troll loomed next to him.

The fat red singer walked to centre-stage as the prelude to the duet began. The audience settled down again. Fun and games among the chorus was all very well–it might even be in the plot–but this was what they'd paid for. This was what it was all about.

Agnes stared at him as Christine walked towards him. Now she could see he wasn't right. Oh, he was fat, in a pillow-up-your-shirt sort of way, but he didn't move like Basilica. Basilica moved lightly on his feet, as fat men often do, giving the effect of a barely tethered balloon.

She glanced at Nanny, who was also watching him carefully. She couldn't see Granny Weatherwax anywhere. That probably meant she was really close.

The expectancy of the audience dragged at them all. Ears opened like petals. The fourth wall of the stage, the big black sucking darkness outside, was a well of silence begging to be filled up.

Christine was walking towards him quite unconcerned. Christine would walk into a dragon's mouth if it had a sign on it saying 'Totally harmless, I promise you'... at least, if it was printed in large, easy-to-understand letters.

No one seemed to want to do anything.

It was a famous duet. And a beautiful one. Agnes ought to know. She'd been singing it all last night.

Christine took the false Basilica's hand and, as the opening bars of the duet began, opened her mouth

'Stop right there!'

Agnes put everything she could into it. The chandelier tinkled.

The orchestra went silent in a skid of wheezes and twangs.

In a fading of chords and a dying of echoes, the show stopped.

Walter Plinge sat in the candlelit gloom under the stage, his hands resting on his lap. It was not often that Walter Plinge had nothing to do, but, when he did have nothing to do, he did nothing.

He liked it down here. It was familiar. The sounds of the opera filtered through. They were muffled, but that didn't matter. Walter knew all the words, every note of music, every step of every dance. He needed the actual performances only in the same way that a clock needs its tiny little escapement mechanism; it kept him ticking nicely.

Mrs Plinge had taught him to read using the old programmes. That's how he knew he was part of it all. But he knew that anyway. He'd cut what teeth he had on a helmet with horns on it. The first bed he could remember was the very same trampoline used by Dame Gigli in the infamous Bouncing Gigli incident.

Walter Plinge lived opera. He breathed its songs, painted its scenery, lit its fires, washed its floors and shined its shoes. Opera filled up places in Walter Plinge that might otherwise have been empty.

And now the show had stopped.

But all the energy, all the raw pent-up emotion that is dammed up behind a show–all the screaming, the fears, the hopes, the desires–flew on, like a body hurled from the wreckage.

The terrible momentum smashed into Walter Plinge like a tidal wave hitting a teacup.

It propelled him out of his chair and flung him against the crumbling scenery.

He slid down and rolled into a twitching heap on the floor, clapping his hands over his ears to shut out the sudden, unnatural silence.

A shape stepped out of the shadows.

Granny Weatherwax had never heard of psychiatry and would have had no truck with it even if she had. There are some arts too black even for a witch. She practised headology–practised, in fact, until she was very good at it. And though there may be some superficial similarities between a psychiatrist and a headologist, there is a huge practical difference. A psychiatrist, dealing with a man who fears he is being followed by a large and terrible monster, will endeavour to convince him that monsters don't exist. Granny Weatherwax would simply give him a chair to stand on and a very heavy stick.

'Stand up, Walter Plinge,' she said.

Walter stood up, staring straight ahead of him. 'It's stopped! It's stopped! It's bad luck to stop the show!' he said hoarsely.

'Someone better start it again,' said Granny.

'You can't stop the show! It's the show!'

'Yes. Someone better start it again, Walter Plinge.'

Walter didn't appear to notice her. He pawed aimlessly through his stack of music and ran his hands through the drifts of old programmes. One hand touched the keyboard of the harmonium and played a few neurotic notes.

'Wrong to stop. Show must go on...'

'Mr Salzella is trying to stop the show, isn't he, Walter?'

Walter's head shot up. He stared straight ahead of him.

'You haven't seen anything, Walter Plinge!' he said, in a voice so like Salzella's that even Granny raised an eyebrow. 'And if you tell lies, you will be locked up and I'll see to it that there's big trouble for your mother!'

Granny nodded.

'He found out about the Ghost, didn't he?' she said. 'The Ghost who comes out when he has a mask on... doesn't he, Walter Plinge? And the man thought: I can use that. And when it's time for the Ghost to be caught... well, there is a Ghost that can be caught. And the best thing is that everyone will believe it. They'll feel bad about themselves, maybe, but they'll believe it. Even Walter Plinge won't be certain, 'cos his mind's all tangled up.'

Granny took a deep breath. 'It's tangled, but it ain't twisted.' There was a sigh. 'Well, matters will have to resolve themselves. There's nothing else for it.'

She removed her hat and fished around in the point. 'I don't mind tellin' you this, Walter,' she said, 'because you won't understand and you won't remember. There was a wicked ole witch once called Black Aliss. She was an unholy terror. There's never been one worse or more powerful. Until now. Because I could spit in her eye and steal her teeth, see. Because she didn't know Right from Wrong, so she got all twisted up and that was the end of her.

'The trouble is, you see, that if you do know Right from Wrong you can't choose Wrong. You just can't do it and live. So... if I was a bad witch I could make Mister Salzella's muscles turn against his bones and break them where he stood... if I was bad. I could do things inside his head, change the shape he thinks he is, and he'd be down on what'd been his knees and begging to be turned into a frog... if I was bad. I could leave him with a mind like a scrambled egg, listening to colours and hearing smells... if I was bad. Oh, yes.' There was another sigh, deeper and more heartfelt. 'But I can't do none of that stuff: That wouldn't be Right.'

She gave a deprecating little chuckle. And if Nanny Ogg had been listening, she would have resolved as follows: that no maddened cackle from Black Aliss of infamous memory, no evil little giggle from some crazed vampyre whose morals were worse than his spelling, no sidesplitting guffaw from the most inventive torturer, was quite so unnerving as a happy little chuckle from a Granny Weatherwax about to do what's best.

From the point of her hat Granny withdrew a paper-thin mask. It was a simple face–smooth, white, basic. There were semi-circular holes for the eyes. It was neither happy nor sad.

She turned it over in her hands. Walter seemed to stop breathing.

'Simple thing, ain't it?' said Granny. 'Looks beautiful, but it's really just a simple bit of stuff, just like any other mask. Wizards could poke at this for a year and still say there was nothing magic about it, eh? Which just shows how much they know, Walter Plinge. '

She tossed it to him. He caught it hungrily and pulled it over his face.

Then he stood up in one flowing movement, moving like a dancer.

'I don't know what you are when you're behind the mask,' said Granny, 'but "ghost" is just another word for "spirit" and "spirit" is just another word for "soul". Off you go, Walter Plinge.'

The masked figure did not move.

'I meant... off you go, Ghost. The show must go on.'

The mask nodded, and darted away.

Granny slapped her hands together like the crack of doom.

'Right! Let's do some good!' she said, to the universe at large.

Everyone was looking at her.

This was a moment in time, a little point between the past and future, when a second could stretch out and out...

Agnes felt the blush begin. It was heading for her face like the revenge of the volcano god. When it got there, she knew, it would be all over for her.

You'll apologize, Perdita jeered.

'Shut up!' shouted Agnes.

She strode forward before the echo had had time to come back from the further ends of the auditorium, and wrenched at the red mask.

The entire chorus came in on cue. This was opera, after all. The show had stopped, but opera continued...

'Salzella!'

He grabbed Agnes, clamping his hand over her mouth. His other hand flew to his belt and drew his sword.

It wasn't a stage prop. The blade hissed through the air as he spun to face the chorus.

'Oh dear oh dear oh dear,' he said. 'How extremely operatic of me. And now, I fear, I shall have to take this poor girl hostage. It's the appropriate thing to do, isn't it?'

He looked around triumphantly. The audience watched in fascinated silence.

'Isn't anyone going to say "You won't get away with this"?' he said.

'You won't get away with this,' said André, from the wings.

'You have the place surrounded, I have no doubt?' said Salzella brightly.

'Yes, we have the place surrounded.'

Christine screamed and fainted.

Salzella smiled even more brightly.

'Ah, now there's someone operatic!' he said. 'But, you see, I am going to get away with it, because I don't think operatically. Myself and this young lady here are going to go down to the cellars where I may, possibly, leave her unharmed. I doubt very much that you have the cellars surrounded. Even I don't know everywhere they go, and believe me my knowledge is really rather extensive'

He paused. Agnes tried to break free, but his grip tightened around her neck.

'By now,' he said, 'someone should have said: "But why, Salzella?" Honestly, do I have to do everything around here?'

Bucket realized he had his mouth open. 'That's what I was going to say!' he said.

'Ah, good. Well, in that case, I should say something like: Because I wanted to. Because I rather like money, you see. But more than that'- he took a deep breath–'I really hate opera. I don't want to get needlessly excited about this, but opera, I am afraid, really is dreadful. And I have had enough. So, while I have the stage, let me tell you what a wretched, selfadoring, totally unrealistic, worthless artform it is, what a terrible waste of fine music, what a–'

There was a whirr off on one side of the stage. The skirts of costumes began to flap. Dust flew up.

André looked around. Beside him, the wind machine had started up. The handle was turning by itself.

Salzella turned to see what everyone was staring at.

The Ghost had dropped lightly on to the stage. His opera cloak billowed around him... operatically.

He bowed slightly, and drew his sword.

'But you're dea–' Salzella began. 'Oh, yes! A ghost of a Ghost! Totally unbelievable and an offence against common sense, in the best operatic tradition! This was really too much to hope for!'

He thrust Agnes away, and nodded happily.

'That's what opera does to a man,' he said. 'It rots the brain, you see, and I doubt whether he had too much of that to begin with. It drives people mad. Mad, d'you hear me, mad!! Ahem. They act irrationally. Don't you think I've watched you, over the years? It's like a hothouse for insanity!! D'you hear me? Insanity!!'

He and the Ghost began to circle one another.

'You don't know what it has been like, I assure you, being the only sane man in this madhouse!! You believe anything!! You'd prefer to believe a ghost can be in two places at once than that there might simply be two people!! Even Pounder thought he could blackmail me!! Poking around in places that he shouldn't!! Well, of course, I had to kill him for his own good. This place sends even ratcatchers mad!! And Undershaft... well, why couldn't he have forgotten his glasses like he usually did, eh?'

He lashed out with his sword. The Ghost parried.

'And now I'll fight your Ghost,' he said, moving forward in a flurry of strokes, 'and you'll notice that our Ghost here doesn't actually know how to fence... because he only knows stage-fencing, you see... where the whole point, of course, is simply to hit the other fellow's sword with a suitably impressive metallic noise... so that you can die very dramatically merely because he's carefully thrust his sword under your armpit...'

The Ghost was forced to retreat under the onslaught, until he fell backwards over the unconscious body of Christine.

'See?' said Salzella. 'That's what comes of believing in opera!!!'

He reached down quickly and tugged the mask off Walter Plinge's face.

'Really, Walter!!! You are a bad boy!!!!'

'Sorry Mr Salzella!'

'Look how everyone's staring!!!!'

'Sorry Mr Salzella!'

The mask crumpled in Salzella's fingers. He let the fragments tumble to the floor. Then he pulled Walter to his feet.

'See, company? This is your luck!!! This is your Ghost!!! Without his mask he's just an idiot who can hardly tie his shoelaces!!! Ahahaha!!!! Ahem. It's all your fault, Walter Plinge...'

'Yes Mr Salzella!'

'No.'

Salzella looked around.

'No one would believe Walter Plinge. Even Walter Plinge gets confused about the things Walter Plinge sees. Even his mother was afraid he might have murdered people. People could accept just about anything of a Walter Plinge.'

There was a steady tapping noise.

The trapdoor opened beside Salzella.

A pointy hat appeared slowly, followed by the rest of Granny Weatherwax, with her arms folded. She glared at Salzella as the floor clicked into place. Her foot stopped tapping on the boards.

'Well, well,' he said. 'Lady Esmerelda, eh?'

'I'm stoppin' bein' a lady, Mr Salzella.'

He glanced up at the pointy hat. 'So you are a witch instead?'

'Yes, indeed.'

'A bad witch, no doubt?'

'Worse.'

'But this,' said Salzella, 'is a sword. Everyone knows witches can't magic iron and steel. Get out of my way!!!'

The sword hissed down.

Granny thrust out her hand. There was a blur of flesh and steel and...

...she held the sword, by the blade.

'Tell you what, Mr Salzella,' she said, levelly, 'it ought to be Walter Plinge who finishes this, eh? It's him you harmed, apart from the ones you murdered, o' course. You didn't need to do that. But you wore a mask, didn't you? There's a kind of magic in masks. Masks conceal one face, but they reveal another. The one that only comes out in darkness. I bet you could do just what you liked, behind a mask... ?'

Salzella blinked at her. He pulled on his sword, tugged hard on a sharp blade held in an unprotected hand.

There was a groan from several members of the chorus. Granny grinned. Her knuckles whitened as she redoubled her grip.

She turned her head towards Walter Plinge. 'Put your mask on, Walter.'

Everyone looked down at the crumpled cardboard on the stage.

'Don't have one any more Mistress Weatherwax!'

Granny followed his gaze. 'Oh deary, deary me,' she said. 'Well, I can see we shall have to do something about that. Look at me, Walter.'

He did as he was told. Granny's eyes half-closed. 'You... trust Perdita, don't you, Walter?'

'Yes Mistress Weatherwax!'

'That's good, because she's got a new mask for you, Walter Plinge. A magic one. It's just like your old one, d'you see, only you wear it under your skin and you don't have to take it off and no one but you will ever need to know it's there. Got it, Perdita?'

'But I–' Agnes began.

'Got it?'

'Er... oh, yes. Here it is. Yes. I've got it in my hand.' She waved an empty hand vaguely.

'You're holding it the wrong way up, my girl!'

'Oh. Sorry.'

'Well? Give it to him, then.'

'Er. Yes.'

Agnes advanced on Walter.

'Now you take it, Walter,' said Granny, still gripping the sword.

'Yes Mistress Weatherwax...'

He reached out towards Agnes. As he did so, she was sure that, just for a moment, there was a faint pressure on her fingertips.

'Well? Put it on!'

Walter looked uncertain.

'You do believe there's a mask there, don't you, Walter?' Granny demanded. 'Perdita's sensible and she knows an invisible mask when she sees one.'

He nodded, slowly, and raised his hands to his face.

And Agnes was sure that he'd somehow come into focus. Almost certainly nothing had happened that could be measured with any kind of instrument, any more than you could weigh an idea or sell good fortune by the yard. But Walter stood up, smiling faintly.

'Good,' said Granny. She stared at Salzella.

'I reckon you two should fight again,' she said. 'But it can't be said I'm unfair. I expect you've got a Ghost mask somewhere? Mrs Ogg saw you waving it, see. And she's not as gormless as she looks–'

'Thank you,' said a fat ballerina.

'-so she thought, how could people still say afterwards that they'd seen the Ghost? 'Cos that's how you recognize the Ghost, by his mask. So there's two masks.'

Under her gaze, telling himself that he could resist any time he wanted to, Salzella reached into his jacket and produced his own mask.

'Put it on, then.' She let go of the sword. 'Then who you are can fight who he is.'

Down in the pit, the percussionist stared as his sticks rose and began a drum roll.

'Are you doing that, Gytha?' said Granny Weatherwax.

'I thought you were.'

'It's opera, then. The show must go on.'

Walter Plinge raised his sword. The masked Salzella glanced from him to Granny, and then lunged.

The swords met.

It was, Agnes realized, stage-fighting. The swords clashed and rattled as the fighters danced back and forth across the stage. Walter wasn't trying to hit Salzella. Every thrust was parried. Every opportunity to strike back, as the director of music grew more angry, was ignored.

'This isn't fighting!' Salzella shouted, standing back. 'This is'

Walter thrust.

Salzella staggered away, until he cannoned into Nanny Ogg. He lurched sideways. Then he staggered forward, dropped on to one knee, got unsteadily to his feet again, and staggered into the centre of the stage.

'Whatever happens,' he gasped, wrenching off his mask, 'it can't be worse than a season of opera!!!! I don't mind where I'm going so long as there are no fat men pretending to be thin boys, and no huge long songs which everyone says are so beautiful just because they don't understand what the hell they're actually about!!!! Ah- Ahargh...'

He slumped to the floor.

'But Walter didn't–' Agnes began.

'Shut up,' said Nanny Ogg, out of the corner of her mouth.

'But he hasn't–' Bucket began.

'Incidentally, another thing I can't stand about opera,' said Salzella, rising to his feet and reeling crabwise towards the curtains, 'are the plots. They make no sense!! And no one ever says so!!! And the quality of the acting? It's nonexistent!! Everyone stands around watching the person who's singing. Ye gods, it's going to be a relief to put that behind... ah... argh...'

He slumped to the floor.

'Is that it?' said Nanny.

'Shouldn't think so,' said Granny Weatherwax.

'As for the people who attend opera,' said Salzella, struggling upright again and staggering sideways, 'I think I just possibly hate them even worse!!! They're so ignorant!!! There's hardly a one of them out there who knows the first thing about music!!! They go on about tunes!!! They spend all day endeavouring to be sensible human beings, and then they walk in here and they leave their intelligence on a nail by the door–'

'Then why didn't you just leave?' snapped Agnes. 'If you'd stolen all this money why didn't you just go away somewhere, if you hated it so much?'

Salzella stared at her while swaying back and forth. His mouth opened and shut once or twice, as if he were trying out unfamiliar words.

'Leave?' he managed. 'Leave? Leave the opera?... Argh argh argh...'

He hit the floor again.

André prodded the fallen director. 'Is he dead yet?' he said.

'How can he be dead?' said Agnes. 'Good grief, can't anyone see that ?'

'You know what really gets me down,' said Salzella, rising to his knees, 'is the way that in opera everyone takes such a long!!!!!... time!!!!!... to!!!!!... argh... argh... argh...'

He keeled over.

The company waited for a while. The audience held its collective breath.

Nanny Ogg poked him with a boot. 'Yep, that's about it. Looks like he's gone down for the last curtain call,' she said.

'But Walter didn't stab him!' said Agnes. 'Why won't anyone listen? Look, the sword isn't even sticking in him! It's just tucked between his body and his arm, for heaven's sake!'

'Yes,' said Nanny. 'I s'pose, really, it's a shame he dint notice that.' She scratched at her shoulder. 'Here, these ballet dresses really tickle...'

'But he's dead!'

'Got a bit overexcited, perhaps,' said Nanny, fidgeting with a strap.

'Overexcited?'

'Frantic. You know these artistic types. Well, you are one, of course.'

'He's really dead?' said Bucket.

'Seems to be,' said Granny. 'One of the best operatic deaths ever, I wouldn't mind betting.'

'That's terrible!!' Bucket grabbed the former Salzella by the collar and hauled him upright. 'Where's my money? Come on, out with it, tell me what you've done with my money!!! I don't hear you!!!! He's not saying anything!!!'

'That's on account of being dead,' said Granny. 'Not talkative, the deceased. As a rule.'

'Well, you're a witch!!! Can't you do that thing with the cards and the glasses?'

'Well, yes... we could have a poker game,' said Nanny. 'Good idea.'

'The money is in the cellars,' said Granny. 'Walter'll show you.'

Walter Plinge clicked his heels. 'Certainly,' he said. 'I would be glad to.'

Bucket stared. It was Walter Plinge's voice and it was coming out of Walter Plinge's face, but both face and voice were different. Subtly different. The voice had lost the uncertain, frightened edge. The lopsided look had gone from the face.

'Good grief,' Bucket murmured, and let go of Salzella's coat. There was a thump.

'And since you're going to be needing a new director of music,' said Granny, 'you could do worse than look to Walter here.'

'Walter?'

'He knows everything there is to know about opera,' said Granny. 'And everything about the Opera House, too.'

'You should see the music he's written–' said Nanny.

'Walter? Musical director?' said Bucket.

'-stuff you can really hum–'

'Yes, I think you might be surprised,' said Granny.

'-there's one with lots of sailors dancin' around singin' about how there's no women–'

'This is Walter, isn't it?'

'-and then some bloke called Les who's miserable all the time–'

'Oh, this is Walter,' said Granny. 'The same person.

'-and there's one, hah, with all cats all leapin' around all singin', that was fun,' Nanny burbled. 'Can't imagine how he thought up that one–'

Bucket scratched his chin. He was feeling lightheaded enough as it was.

'And he's trustworthy,' said Granny. 'And he's honest. And he knows all about the Opera House, as I said. And... where everything is...'

That was enough for Mr Bucket. 'Want to be director of music, Walter?' he said.

'Thank you, Mr Bucket,' said Walter Plinge. 'I should like that very much. But what about cleaning the privies?'

'Sorry?'

'I won't have to stop doing them, will I? I've just got them working right.'

'Oh? Right. Really?' Mr Bucket's eyes crossed for a moment. 'Well, fine. You can sing while you're doing it, if you like,' he added generously. 'And I won't even cut your pay! I'll... I'll raise it! Six... no, seven shiny dollars!'

Walter rubbed his face thoughtfully. 'Mr Bucket...'

'Yes, Walter?'

'I think... you paid Mr Salzella forty shiny dollars...'

Bucket turned to Granny. 'Is he some kind of monster?'

'You just listen to the stuff he's been writin',' said Nanny. 'Amazin' songs, not even in foreign. Will you just look at this stuff...'scuse me...'

She turned her back on the audience–

–twingtwangtwong–

–and twirled round again with a wad of music paper in her hands.

'I know good music when I sees it,' she said, handing it to Bucket and pointing excitedly at extracts. 'It's got blobs and curly bits all over it, see?'

'You have been writing this music?' said Bucket to Walter. 'Which is unaccountably warm?'

'Indeed, Mr Bucket.'

'In my time?'

'There's a lovely song here,' said Nanny, ' "Don't cry for me, Genua". It's very sad. That reminds me, I'd better go and see if Mrs Plinge has come rou... has woken up. I may have overdone it a bit on the stumble.' She ambled off, twitching at bits of her costume, and nudged a fascinated ballerina. 'This balleting doesn't half make you sweat, don't you find?'

'Excuse me, there's something I didn't quite believe,' said André. He took Salzella's sword and tested the blade carefully.

'Ow!' he shouted.

'Sharp, is it?' said Agnes.

'Yes!' André sucked his thumb. 'She caught it in her hand.'

'She's a witch,' said Agnes.

'But it was steel! I thought no one could magic steel! Everyone knows that.'

'I wouldn't be too impressed if I was you,' said Agnes sourly. 'It was probably just some kind of trick...'

André turned to Granny. 'Your hand isn't even scratched! How did... you...'

Her stare held him in its sapphire vice for a moment. When he turned away he looked vaguely puzzled, like a man who can't remember where he's just put something down.

'I hope he didn't hurt Christine,' he mumbled. 'Why isn't anyone seeing to her?'

'Probably because she makes sure she screams and faints before anything happens,' said Perdita, through Agnes.

André set off across the stage. Agnes trailed after him. A couple of dancers were kneeling down next to Christine.

'It'd be terrible if anything happened to her,' said André.

'Oh... yes.'

'Everyone says she's showing such promise...'

Walter stepped up beside him. 'Yes. We should get her somewhere,' he said. His voice was clipped and precise.

Agnes felt the bottom start to drop out of her world. 'Yes, but... you know it was me doing the singing.'

'Oh, yes... yes, of course...' said André, awkwardly. 'But...well... this is opera... you know...'

Walter took her hand.

'But it was me you taught!' she said desperately.

'Then you were very good,' said Walter. 'I suspect she will never be quite that good, even with many months of my tuition. But, Perdita, have you ever heard of the words "star quality"?'

'Is it the same as talent?' snapped Agnes.

'It is rarer.'

She stared at him. His face, however it was controlled now, was quite handsome in the glare of the footlights.

She pulled her hand free. 'I liked you better when you were Walter Plinge,' she said.

Agnes turned away, and felt Granny Weatherwax's gaze on her. She was sure it was a mocking gaze.

'Er... we ought to get Christine into Mr Bucket's office,' André said.

This seemed to break some sort of spell.

'Yes, indeed!!!' said Bucket. 'And we can't leave Mr Salzella corpsing on stage, either. You two, you'd better take him backstage. The rest of you... well, it was nearly over anyway... er... that's it. The... opera is over...'

'Walter Plinge!'

Nanny Ogg entered, supporting Mrs Plinge. Walter's mother fixed him with a beady gaze. 'Have you been a bad boy?'

Mr Bucket walked over to her and patted her hand. 'I think you'd better come along to my office, too,' he said. He handed the sheaf of music to André, who opened it at random.

André gave it a glance, and then stared. 'Hey... this is good,' he said.

'Is it?'

André looked at another page. 'Good heavens!'

'What? What?' said Bucket.

'I've just never... I mean, even I can see... tum-ti TUM tum-tum...yes... Mr Bucket, you do know this isn't opera? There's music and... yes... dancing and singing all right, but it's not opera. Not opera at all. A long way from opera.'

'How far? You don't mean...' Bucket hesitated, savouring the idea, 'you don't mean that it's just possible that you put music in and you get money out?'

André hummed a few bars. 'This could very well be the case, Mr Bucket.'

Bucket beamed. He put one arm around André and the other around Walter. 'Good!!!!!' he said. 'This calls for a very lar... for a medium-sized mm drink .....

One by one, or in groups, the singers and dancers left the stage. And the witches and Agnes were left alone.

'Is that it?' said Agnes.

'Not quite yet,' said Granny.

Someone staggered on to the stage. A kindly hand had bandaged Enrico Basilica's head, and presumably another kindly hand had given him the plate of spaghetti he was holding. Mild concussion still seemed to have him in its grip. He blinked at the witches and then spoke like a man who'd lost his hold on immediate events and so was clinging hard to more ancient considerations.

'Summon give me some 'ghetti,' he said.

'That's nice,' said Nanny.

'Hah! 'Ghetti is fine for them as likes it... but not me! Hah! Yes!' He turned and peered muzzily at the darkness of the audience.

'You know what I'm goin' to do? You know what I'm goin' to do now? I'm sayin' goodbye to Enrico Basilica! Oh yes! He's chewed his last tentacle! I'm goin' to go right out now and have eight pints of Turbot's Really Odd. Yes! And probably a sausage in a bun! And then I'm goin' down to the music hall to hear Nellie Stamp sing "A Winkles No Use if You Don't Have a Pin"–and if I sing again here it's goin' to be under the proud old name of Henry Slugg, do you hear-?'

There was a shriek from somewhere in the audience. 'Henry Slugg?'

'Er... yes?'

'I thought it was you! You've grown a beard and stuffed a haystack down your trousers but, I thought, under that little mask, that's my Henry, that was!'

Henry Slugg shaded his eyes from the footlights' glare.

'...Angeline?'

'Oh, no!' said Agnes, wearily. 'This sort of thing does not happen.'

'Happens in the theatre all the time,' said Nanny Ogg.

'It certainly does,' said Granny. 'It's only a mercy he doesn't have a long-lost twin brother.'

There was the sound of much scuffling in the audience. Someone was climbing along a row, dragging someone else.

'Mother!' came a voice from the gloom. 'What do you think you are doing?'

'You just come with me, young Henry!'

'Mother, we can't go up on the stage... !'

Henry Slugg frisbeed the plate into the wings, clambered down from the stage and heaved himself over the edge of the orchestra pit, assisted by a couple of violinists.

They met at the first row of seats. Agnes could just hear their voices.

'I meant to come back. You know that!'

'I wanted to wait but, what with one thing and another... especially one thing. Come here, young Henry. . .'

'Mother, what is happening?'

'Son... you know I always said your father was Mr Lawsy the eel juggler?'

'Yes, of–'

'Please, both of you, come back to my dressingroom! I can see we've got such a lot to talk about.'

'Oh, yes. A lot...'

Agnes watched them go. The audience, who could spot opera even if it wasn't being sung, applauded.

'All right,' she said. 'And now is it the end?'

'Nearly,' said Granny.

'Did you do something to everyone's heads?'

'No, but I felt like smacking a few,' said Nanny.

'But no one said "thank you" or anything!'

'Often the case,' said Granny.

'Too busy thinking about the next performance,' said Nanny. 'The show must go on,' she added.

'That's... that's madness!'

'It's opera. I noticed that even Mr Bucket's caught it, too,' said Nanny. 'And that young André has been rescued from being a policeman, if I'm any judge.'

'But what about me?'

'Oh, them as makes the endings don't get them,' said Granny. She brushed an invisible speck of dust off her shoulder.

'I expect we'd better be gettin' along, Gytha,' she said, turning her back on Agnes. 'Early start tomorrow.'

Nanny walked forward, shading her eyes as she stared out into the dark maw of the auditorium.

'The audience haven't gone, you know,' she said. 'They're still sitting out there.'

Granny joined her, and peered into the gloom. 'I can't imagine why,' she said. 'He did say the opera's over...

They turned and looked at Agnes, who was standing in the centre of the stage and glowering at nothing.

'Feeling a bit angry?' said Nanny. 'Only to be expected.'

'Yes!'

'Feeling that everything's happened for other people and not for you?'

'Yes!'

'But,' said Granny Weatherwax, 'look at it like this: what's Christine got to look forward to? She'll just become a singer. Stuck in a little world. Oh, maybe she'll be good enough to get a little fame, but one day the voice'll crack and that's the end of her life. You have got a choice. You can either be on the stage, just a performer, just going through the lines... or you can be outside it, and know how the script works, where the scenery hangs, and where the trapdoors are. Isn't that better?'

'No!'

The infuriating thing about Nanny Ogg and Granny Weatherwax, Agnes thought later, was the way they sometimes acted in tandem, without exchanging a word. Of course, there were plenty of other things–the way they never thought that meddling was meddling if they did it; the way they automatically assumed that everyone else's business was their own; the way they went through life in a straight line; the way, in fact, that they arrived in any situation and immediately started to change it. Compared to that, acting on unspoken agreement was a mere minor annoyance, but it was here and up close.

They walked towards her, and each laid a hand on her shoulder.

'Feeling angry?' said Granny.

'Yes!'

'I should let it out then, if I was you,' said Nanny.

Agnes shut her eyes, clenched her fists, opened her mouth and screamed.

It started low. Plaster dust drifted down from the ceiling. The prisms on the chandelier chimed gently as they shook.

It rose, passing quickly through the mysterious pitch at fourteen cycles per second where the human spirit begins to feel distinctly uncomfortable about the universe and the place in it of the bowels. Small items around the Opera House vibrated off shelves and smashed on the floor.

The note climbed, rang like a bell, climbed again. In the Pit, all the violin strings snapped, one by one.

As the tone rose, the crystal prisms shook in the chandelier. In the bar, champagne corks fired a salvo. Ice jingled and shattered in its bucket. A line of wine-glasses joined in the chorus, blurred around the rims, and then exploded like hazardous thistledown with attitude.

There were harmonics and echoes that caused strange effects. In the dressing-rooms the No. 3 greasepaint melted. Mirrors cracked, filling the ballet school with a million fractured images.

Dust rose, insects fell. In the stones of the Opera House tiny particles of quartz danced briefly...

Then there was silence, broken by the occasional thud and tinkle.

Nanny grinned.

'Ah,' she said, 'now the opera's over.'

Salzella opened his eyes.

The stage was empty, and dark, and nevertheless brilliantly lit. That is, a huge shadowless light was streaming from some unseen source and yet, apart from Salzella himself, there was nothing for it to illuminate.

Footsteps sounded in the distance. Their owner took some time to arrive, but when he stepped into the liquid air around Salzella he seemed to burst into flame.

He wore red: a red suit with red lace, a red cloak, red shoes with ruby buckles, and a broad-brimmed red hat with a huge red feather. He even walked with a long red stick, bedecked with red ribbons. But for someone who had taken such meticulous trouble with his costume, he'd been remiss in the matter of his mask. It was a crude one of a skull, such as might be bought in any theatrical shop–Salzella. could even see the string.

'Where did everyone go?' Salzella demanded. Unpleasant recent memories were beginning to bubble up in his mind. He couldn't quite recall them clearly at the moment, but the taste of them was bad.

The figure said nothing.

'Where's the orchestra? What happened to the audience?'

There was a barely perceptible shrug from the tall red figure.

Salzella began to notice other details. What he had thought was the stage seemed slightly gritty underfoot. The ceiling above him was a long way away, perhaps as far away as anything could be, and was filled with cold, hard points of light.

'I asked you a question!'

THREE QUESTIONS, IN FACT.

The words turned up on the inside of Salzella's ears with no suggestion that they had had to travel like normal sound.

'You didn't answer me!'

SOME THINGS YOU HAVE TO WORK OUT FOR YOURSELF, AND THIS IS ONE OF THEM, BELIEVE ME.

'Who are you? You're not a member of the cast, I know that! Take off that mask!'

AS YOU WISH. I DO LIKE TO GET INTO THE SPIRIT OF THE THING.

The figure removed its mask.

'And now take off that other mask!' said Salzella, as the frozen fingers of dread rose through him.

Death touched a secret spring on the stick. A blade shot out, so thin that it was transparent, its edge glittering blue as air molecules were sliced into their component atoms.

AH, he said, raising the scythe. THERE I THINK YOU HAVE ME.

It was dark in the cellars, but Nanny Ogg had walked alone in the strange caverns under Lancre and through the night-time forests with Granny Weatherwax. Darkness held no fears for an Ogg.

She struck a match.

'Greebo?'

People had been tramping to and fro for hours. The darkness wasn't private any more. It had taken quite a lot of people to carry all the money, for a start. Up until the end of the opera, there had been something mysterious about these cellars. Now they were just... well... damp underground rooms. Something that had lived here had moved on.

Her foot rattled a piece of pottery.

She grunted as she went down on one knee. Spilt mud and shards of broken pot littered the floor. Here and there, unrooted and snapped, were some unheeded pieces of dead twig.

Only some kind of fool would have stuck bits of wood in pots of mud far underground and expected anything to happen.

Nanny picked one up and sniffed it tentatively. It smelled of mud. And nothing else.

She'd have liked to have-known how it had been done. Just professional interest, of course. And she knew she never would, now. Walter was a busy man now, up in the light. And, for something to begin, other things had to end.

'We all wears a mask of one sort or another,' she said to the damp air. 'No sense in upsetting things now, eh...'

The coach didn't leave until seven o'clock in the morning. By Lancre standards that was practically midday. The witches got there early.

'I was hoping to shop for a few souvenirs,' said Nanny, stamping her feet on the cobbles to keep warm. 'For the kiddies.'

'No time,' said Granny Weatherwax.

'Not that it would have made any difference on account of me not having any money to buy 'em with,' Nanny went on.

'Not my fault if you fritter your money away,' said Granny.

'I don't recall having a single chance to frit.'

'Money's only useful for the things it can do.'

'Well, yes. I could've done with having some new boots, for a start.'

Nanny jiggled up and down a bit, and whistled around her tooth.

'Nice of Mrs Palm to let us stay there gratis,' she said.

'Yes.'

'O' course, I helped out playin' the piano and tellin' jokes.'

'An added bonus,' said Granny, nodding.

'An' of course there was all those little nibbles I prepared. With the Special Party Dip.'

'Yes indeed,' said Granny, poker-faced. 'Mrs Palm was saying only this morning that she's thinking of retiring next year.'

Nanny looked up and down the street again.

'I 'spect young Agnes'll be turning up any minute now,' she said.

'I really couldn't say,' said Granny haughtily.

'Not as though there's much for her here, after all.'

Granny sniffed. 'That's up to her, I'm sure.'

'Everyone was very impressed, I reckon, when you caught that sword in your hand...'

Granny sighed. 'Hah! Yes, I expect they were. They didn't think clearly, did they? People're just lazy. They never think: maybe she had something in her hand, a bit of metal or something. They don't think for a minute it was just a trick. They don't think there's always a perfectly good explanation if you look for it. They probably think it was some kind of magic.'

'Yeah, but... you didn't have anything in your hand, did you?'

'That's not the point. I might have done.' Granny looked up and down the square. 'Besides, you can't magic iron.

'That's very true. Not iron. Now, someone like ole Black Aliss, they could make their skin tougher than steel... but that's just an ole legend, I expect...'

'She could do it all right,' said Granny. 'But you can't go round messin' with cause and effect. That's what sent her mad, come the finish. She thought she could put herself outside of things like cause and effect. Well, you can't. You grab a sharp sword by the blade, you get hurt. World'd be a terrible place if people forgot that.'

'You weren't hurt.'

'Not my fault. I didn't have time.'

Nanny blew on her hands. 'One good thing, though,' she said. 'It's a blessing the chandelier never came down. I was worried about that soon as I saw it. Looks too dramatic for its own good, I thought. First thing I'd smash, if I was a loony.'

'Yes.'

'Haven't been able to find Greebo since last night.'

'Good.'

'He always turns up, though.'

'Unfortunately.'

There was a clatter as the coach swung around the corner.

It stopped.

Then the coachman tugged on the reins and it did a Uturn and disappeared again.

'Esme?' said Nanny, after a while.

'Yes?'

'There's a man and two horses peering at us around the corner.' She raised her voice. 'Come on, I know you're there! Seven o'clock, this coach is supposed to leave! Did you get the tickets, Esme?'

'Me?'

'Ah,' said Nanny uncertainly. 'So... we haven't got eighty dollars for the tickets, then?'

'What've you got stuffed up your elastic?' said Granny as the coach advanced cautiously.

'Nothin' that is legal tender for travellin' purposes, I fear.'

'Then... no, we can't afford tickets.'

Nanny sighed. 'Oh, well, I'll just have to use charm.'

'It's going to be a long walk,' said Granny.

The coach pulled up. Nanny looked up at the driver, and smiled innocently. 'Good morning, my good sir!'

He gave her a slightly frightened but mainly suspicious look. 'Is it?'

'We are desirous of travelling to Lancre but unfortunately we find ourselves a bit embarrassed in the knicker department.'

'You are??

'But we are witches and could prob'ly pay for our travel by, e.g., curing any embarrassing little ailments you may have.'

The coachman frowned. 'I ain't carrying you for nothing, old crone. And I haven't got any embarrassing little ailments!'

Granny stepped forward.

'How many would you like?' she said.

Rain rolled over the plains. It wasn't an impressive Ramtops thunderstorm but a lazy, persistent, low-cloud rain, like a fat fog. It had been following them all day.

The witches had the coach to themselves. Several people had opened the door while it had been waiting to leave, but for some reason had suddenly decided that today's travel plans didn't include a coach ride.

'Making good time,' said Nanny, opening the curtains and peering out of the window.

'I expect the driver's in a hurry.'

'Yes, I 'spect he is.'

'Shut the window, though. It's getting wet in here.'

'Righty-ho.'

Nanny grabbed the strap and then suddenly poked her head out into the rain.

'Stop! Stop! Tell the man to stop!'

The coach dewed to a halt in a sheet of mud.

Nanny threw open the door. 'I don't know, trying to walk home, and in this weather too! You'll catch your death!'

Rain and fog rolled in through the open doorway. Then a bedraggled shape pulled itself over the sill and slunk under the seats, leaving small puddles behind it.

'Tryin' to be independent,' said Nanny. 'Bless 'im.'

The coach got under way again. Granny stared out at the endless darkening fields and the relentless drizzle, and saw another figure toiling along in the mud by the road that would, eventually, reach Lancre. As the coach swept past, it drenched the walker in thin slurry.

'Yes, indeed. Being independent's a fine ambition,' she said, drawing the curtains.

The trees were bare when Granny Weatherwax got back to her cottage.

Twigs and seeds had blown in under the door. Soot had fallen down the chimney. Her home, always somewhat organic, had grown a little closer to its roots in the clay.

There were things to do, so she did them. There were leaves to be swept, and the woodpile to be built up under the eaves. The windsock behind the beehives, tattered by autumn storms, needed to be darned. Hay had to be got in for the goats. Apples had to be stored in the loft. The walls could do with another coat of whitewash.

But there was something that had to be done first. It'd make the other jobs a bit more difficult, but there was no help for that. You couldn't magic iron. And you couldn't grab a sword without being hurt. If that wasn't true, the world'd be all over the place.

Granny made herself some tea, and then boiled up the kettle again. She took a handful of herbs out of a box on the dresser, and dropped them in a bowl with the steaming water. She took a length of clean bandage out of a drawer and set it carefully on the table beside the bowl. She threaded an extremely sharp needle and laid needle and thread beside the bandage. She scooped a fingerful of greenish ointment out of a small tin, and smeared it on a square of lint.

That seemed to be it.

She sat down, and rested her arm on the table, palm-up.

'Well,' she said, to no one in particular, 'I reckon I've got time now.'

The privy had to be moved. It was a job Granny preferred to do for herself. There was something incredibly satisfying in digging a very deep hole. It was uncomplicated. You knew where you were with a hole in the ground. Dirt didn't get strange ideas, or believe that people were honest because they had a steady gaze and a firm handshake. It just lay there, waiting for you to move it. And, after you'd done it, you could sit there in the lovely warm knowledge that it'd be months before you had to do it again.

It was while she was at the bottom of the hole that a shadow fell across it.

'Afternoon, Perdita,' she said without looking up.

She lifted another shovelful to head-height and flung it over the edge.

'Come home for a visit, have you?' she said.

She rammed the shovel into the clay at the bottom of the hole again, winced, and forced it down with her foot.

'Thought you were doing very well in the opera,' she went on. "Course, I'm not an expert in these things. Good to see young people seeking their fortune in the big city, though.'

She looked up with a bright, friendly smile.

'I see you've lost a bit of weight, too.' Innocence hung from her words like loops of toffee.

'I've been... taking exercise,' said Agnes.

'Exercise is a fine thing, certainly,' said Granny, getting back to her digging. 'Though they do say you can have too much of it. When are you going back?'

'I... haven't decided.'

'Weeelll, it doesn't pay to be always planning. Don't tie yourself down the whole time, I've always said that. Staying with your ma, are you?'

'Yes,' said Agnes.

'Ah? Only Magrat's old cottage is still empty. You'd be doing everyone a favour if you aired it out a bit. You know... as long as you're here.'

Agnes said nothing. She couldn't think of anything to say.

'Funny ole thing,' said Granny, hacking around a particularly troublesome tree root. 'I wouldn't tell everyone, but I was only thinking the other day, about when I was younger and called myself Endemonidia...'

'You did? When?'

Granny rubbed her forehead with her bandaged hand, leaving a clay-red smudge.

'Oh, for about three, four hours,' she said. 'Some names don't have the stayin' power. Never pick yourself a name you can't scrub the floor in.'

She threw her shovel out of the hole. 'Give me a hand up, will you?'

Agnes did so. Granny brushed the dirt and leafmould off her apron and tried to stamp the clay off her boots.

'Time for a cup of tea, eh?' she said. 'My, you are looking well. It's the fresh air. Too much stuffy air in that Opera House, I thought.'

Agnes tried in vain to detect anything in Granny Weatherwax's eyes other than transparent honesty and goodwill.

'Yes. I thought so, too,' she said. 'Er... you've hurt your hand?'

'It'll heal. A lot of things do.'

She shouldered her shovel and headed towards the cottage; and then, halfway up the path, turned and looked back.

'This is just me askin', you understand, in a kind neighbourly way, takin' an interest sort of thing, wouldn't be human if I didn't–'

Agnes sighed. 'Yes?'

'...you got much to do with your evenin's these days?'

There was just enough rebellion left in Agnes to put a sarcastic edge on her voice. 'Oh? Are you offering to teach me something?'

'Teach? No,' said Granny. 'Ain't got the patience for teaching. But I might let you learn.'

'When shall we three meet again?'

'We haven't met once, yet.'

'O' course we have. I've person'ly known you for at least'

'I mean we Three haven't Met. You know... officially...'