'We're old friends, after all. Old friends of her grandma and her mum, anyway, and that's practic'ly the same.'

'Remember those eyes in the teacup?' said Nanny. 'She could be under the gaze of some strange occult force! We got to be careful. People can be very tricky when they're in the grip of a strange occult force. Remember Mr Scruple over in Slice?'

'That wasn't a strange occult force. That was acid stomach.'

'Well, it certainly seemed strangely occult for a while. Especially if the windows were shut.' Their perambulation had taken them to the Opera House's stage-door. Granny looked up at a line of posters. 'La Triviata,' she read aloud. 'The Ring of the Nibelungingung. . . ?'

'Well, basically there are two sorts of opera,' said Nanny, who also had the true witch's ability to be confidently expert on the basis of no experience whatsoever. 'There's your heavy opera, where basically people

sing foreign and it goes like “Oh oh oh, I am dyin', oh, I am dyin', oh, oh, oh, that's what I'm doin”', and there's your light opera, where they sing in foreign and it basically goes “Beer! Beer! Beer! Beer! I like to drink lots of beer!”, although sometimes they drink champagne instead. That's basically all of opera, reely.'

'What? Either dyin' or drinkin' beer?'

'Basically, yes,' said Nanny, contriving to suggest that this was the whole gamut of human experience. 'And that's opera?'

'We-ll. . . there might be some other stuff. But mostly it's stout or stabbin'.' Granny was aware of a presence. She turned. A figure had emerged from the stage-door, carrying a poster, a bucket of glue and a brush. It was a strange figure, a sort of neat scarecrow in clothes slightly too small for it, although, to be truthful, there were probably no clothes that would have fit that body. The ankles and wrists seemed infinitely extensible and independently guided. It encountered the two witches standing at the poster board, and stopped politely. They could see the sentence marshalling itself behind the unfocused eyes. 'Excuse me ladies! The show must go on!' The words were all there and they made sense, but each sentence was fired out into the world as a unit. Granny pulled Nanny to one side. 'Thank you!' They watched in silence as the man, with great and meticulous care, applied paste to a neat rectangle and then affixed the poster, smoothing every crease methodically. 'What's your name, young man?' said Granny. 'Walter!'

'That's a nice beret you have there.'

'My mum bought it for me!' Walter chased the last air bubble to the edge of the paper and stood back. Then, completely ignoring the witches in his preoccupation with his task, he picked up the paste-pot and went back inside. The witches stared at the new poster in silence. 'Y'know, I wouldn't mind seein' an operation,' said Nanny, after a while. 'Senior Basilica did give us the tickets.'

'Oh, you know me,' said Granny. 'Can't be having with that sort of thing at all.' Nanny looked sideways at her, and grinned to herself. This was a familiar Weatherwax opening line. It meant: Of course I want to, but you've got to persuade me. 'You're right, o' course,' she said. 'It's for them folks in all their fine carriages. It's not for the likes of us.' Granny looked hesitant for a moment. 'I expect it's having ideas above our station,' Nanny went on. 'I expect if we went in they'd say: Be off, you nasty ole crones. . .'

'Oh, they would, would they?'

'I don't expect they want common folk like what we are comin' in with all those smart nobby people,' said Nanny. 'Is that a fact? Is that a fact, madam? You just come with me!' Granny stalked round to the front of the building, where people were already alighting from coaches. She pushed her way up the steps and shouldered through the crowd to the ticket office. She leaned forward. The man behind the grille leaned back.

'Nasty old crones, eh?' she snapped. 'I beg your pardon-?'

'Not before time! See here, we've got tickets for-' She looked down at the pieces of cardboard, and pulled Nanny Ogg over. 'It says here Stalls. The cheek of it! Stalls? Us?' She turned back to the ticket man. 'See here, Stalls aren't good enough, we want seats in'-she looked up at the board by the ticket window-'the Gods. Yes, that sounds about right.'

'I'm sorry? You've got tickets for Stalls seats and you want to exchange them for seats in the Gods?'

'Yes, and don't you go expecting us to pay any more money!'

'I wasn't going to ask you for-'

'Just as well!' said Granny, smiling triumphantly. She looked approvingly at the new tickets. 'Come, Gytha.'

'Er, excuse me,' said the man as Nanny Ogg turned away, 'but what is that on your shoulders?'

'It's. . . a fur collar,' said Nanny. 'Excuse me, but I just saw it flick its tail.'

'Yes. I happen to believe in beauty without cruelty.' Agnes was aware of something happening backstage. Little groups of men were forming, and then breaking up as various individuals hurried away about their mysterious tasks. Out in front the orchestra was already tuning up. The chorus was filing on to be A Busy Marketplace, in which various jugglers, gypsies, sword- swallowers and gaily dressed yokels would be entirely unsurprised at an apparently drunken baritone strolling on to sing an enormous amount of plot at a passing tenor. She saw Mr Bucket and Mr Salzella deep in argument with the stage manager. 'How can we search the entire building? This place is a maze!'

'He might have just wandered off somewhere. . . ?'

'He's as blind as a bat without those glasses.'

'But we can't be certain something's happened to him.'

'Oh, Yes? You didn't say that when we opened the double-bass case. You were certain' he was going to be inside. Admit it.'

'I. . . wasn't expecting just to find a smashed double bass, yes. But I was feeling a bit mithered at that point.' A sword-swallower nudged Agnes. 'What?'

'Curtain up in one minute, dear,' he said, smearing mustard on his sword. 'Has something happened to Dr Undershaft?'

'Couldn't say, dear. You wouldn't have any salt, would you?'

' 'Scuse me. 'Scuse me. Sorry. 'Scuse me. Was that your foot? 'Scuse me. . .' Leaving a trail of annoyed and pained patrons in their wake, the witches trod their way to their seats. Granny elbowed herself comfortable and then, having in some matters the boredom threshold of a four-year-old, said: 'What's happenin' now?' Nanny's skimpy knowledge of opera didn't come to her aid. So she turned to the lady beside her. '

'Scuse me, could I borrow your programme? Thank you. 'Scuse me, could I borrow your spectacles? So kind.' She spent a few moments in careful study. 'This is the overture,' she said. 'It's kind of a free sample of what's going to happen. 'S got a summary of the story, too. La Triviata.' Her lips moved as she read. Occasionally her brow wrinkled.

'Well, it's quite simple reely,' she said, at last. 'A lot of people are in love with one another, there's considerable dressing up as other people and general confusion, there's a cheeky servant, no one really knows who anyone is, a couple of ole dukes go mad, chorus of gypsies, etc. Your basic opera. Someone's prob'ly going to turn out to be someone else's long lost son or daughter or wife or something.'

'Shh!' said a voice behind them. 'Wish we'd brought something to eat,' muttered Granny. 'I think I've got some peppermints in my knicker leg.'

'Shh!'

'I would like my spectacles back, please.'

'Here you are, ma'am. They're not very good, are they?' Someone tapped Nanny Ogg on the shoulder. 'Madam, your fur stole is eating my chocolates!' And someone tapped Granny Weatherwax on her shoulder. 'Madam, kindly remove your hat.' Nanny Ogg choked on her peppermint. Granny Weatherwax turned to the red-faced gentleman behind her. 'You do know what a woman in a pointy hat is, don't you?' she said. 'Yes, madam. A woman in a pointy hat is sitting in front of me.' Granny gave him a stare. And then, to Nanny's surprise, she removed her hat. 'I do beg your pardon,' she said. 'I can see I was inadvertently bad- mannered. Pray excuse me.' She turned back to the stage. Nanny Ogg started breathing again. 'You feeling all right, Esme?'

'Never better.' Granny Weatherwax surveyed the auditorium, oblivious to the sounds around her. 'I assure you, madam, your fur is eating my chocolates. It's started on the second layer!'

'Oh, dear. Show him the little map inside the lid, will you? He's only after the truffles, and you can soon rub the dribble off the others.'

'Do you mind being quiet?'

'I don't mind, it's this man and his chocolates that's making the noise-' A big room, Granny thought. A great big room without windows. . . There was a tingling in her thumbs. She looked at the chandelier. The rope disappeared into an alcove in the ceiling. Her gaze passed along the rows of Boxes. They were all quite crowded. On one, though, the curtains were almost closed, as if someone inside wanted to see out without being seen. Then Granny looked among the Stalls. The audience was mainly human. Here and there was the hulking shape of a troll, although the troll equivalent of operas usually went on for a couple of years. A few dwarf helmets gleamed, although dwarfs normally weren't interested in anything without dwarfs in. There seemed to be a lot of feathers down there, and here and there the glint of jewellery. Shoulders were being worn bare this season. A lot of attention had been paid to appearances. The people were here to look, not to see. She closed her eyes. This was when you started being a witch. It wasn't when you did headology on daft old men, or mixed up medicines, or stuck up for yourself, or knew one herb from another. It was when you opened your mind to the world and carefully examined everything it picked up. She ignored her ears until the sounds of the audience became just a distant buzz.

Or, at least, a distant buzz broken by the voice of Nanny Ogg. 'Says here that Dame Timpani, who sings the part of Quizella, is a diva,' said Nanny. 'So I reckon this is like a part-time job, then. Prob'ly quite a good idea, on account of you have to be able to hold your breath. Good trainin' for the singin'.' Granny nodded without opening her eyes. She kept them closed as the opera started. Nanny, who knew when to leave her friend to her own devices, tried to keep quiet but felt impelled to give out a running commentary. Then she said, 'There's Agnes! Hey, that's Agnes!'

'Stop wavin' and sit down,' murmured Granny, trying to hold on to her waking dream. - Nanny leaned over the balcony. 'She's .dressed up as a gypsy,' she said. 'And now there's a girl come forward to sing'- she peered at the stolen programme-'the famous “Departure” aria, it says here. Now that's what I call a good voice-'

'That's Agnes singin',' said Granny. 'No, it's this girl Christine.'

'Shut your eyes, you daft old woman, and tell me if that isn't Agnes singin',' said Granny. Nanny Ogg obediently shut her eyes for a moment, and then opened them again. 'It's Agnes singing!'

'Yes.'

'But there's that girl with the big smile right out there in front moving her lips and everything!'

'Yes.' Nanny scratched her head. 'Something a bit wrong here, Esme. Can't have people stealing our Agnes's voice.' Granny's eyes were still shut. 'Tell me if the curtains on that Box down there on the right have moved,' she said. 'I just saw them twitch, Esme.'

'Ah.' Granny let herself relax again. She sank into the seat as the aria washed over her, and opened her mind once more. . . Edges, walls, doors. . . Once a space was enclosed it became a universe of its own. Some things remained trapped in it. The music passed through one side of her head and out the other, but with it. came other things, strands of things, echoes of old screams. . . She drifted down further, down below the conscious, into the darkness beyond the circle of firelight. There was fear here. It stalked the place like a great dark animal. It lurked in every corner. It was in the stones. Old terror crouched in the shadows. It was one of the most ancient terrors, the one that meant that no sooner had mankind learned to walk on two legs than it dropped to its knees. It was the terror of impermanence, the knowledge that all this would pass away, that a beautiful voice or a wonderful figure was something whose arrival you couldn't control and whose departure you couldn't delay. It wasn't what she had been looking for, but it was perhaps the sea in which it swam. She went deeper. And there it was, roaring through the night-time of the soul of the place like a deep cold current. As she drew closer she saw that it was not one thing but two, twisted around one another. She reached out. . . Trickery. Lies. Deceit. Murder. 'No!' She blinked.