They looked at one another.

'I'll have a man guard it every minute there's a performance,' said Salzella. 'I'll do it personally, if you like.'

'And he wants Christine to sing Iodine tonight! She's got a voice like a whistle!'

Salzella raised his eyebrows. 'That at least is not ,a problem, is it?' he said.

'Isn't it? It's a key role!'

Salzella put his arm around the owner's shoulders. 'I think perhaps it is time for you to explore a few more little-­known corners of the wonderful world that is opera,' he said.

The stagecoach rolled to. a halt in Sator Square, Ankh­-Morpork. The coach agent was waiting impatiently.

'You're fifteen hours late, Mr Reever!' he shouted.

The coach‑driver nodded impassively. He laid the reins down, jumped off the box, and inspected the horses. There was a certain woodenness about his movements.

Passengers were grabbing their baggage and hurrying away.

'Well?' said the agent.

'We had a picnic,' said the coach‑driver. His face was grey.

'You stopped for a picnic?'

'And a bit of a singsong,' said the driver, pulling the horses' feedbags from under the seat.

'You are telling me that you stopped the mail coach for a picnic and a singsong?'

'Oh, and the cat got stuck up a tree.' He sucked his hand, and the agent noticed that a handkerchief was tied around it.

A hazy look of recollection clouded the driver's eyes. 'And then there were the stories,' he said.

'What stories?'

'The little fat one said everyone had to tell a story to help pass the time.'

'Yes? Well? I don't see how that could slow you down!'

'You should've heard her story. The one about the very tall man and the piano? I was so embarrassed I fell off the coach. I wouldn't use words like that even to my own dear grandmother!'

'And of course,' said the agent, who prided himself on his ironic approach, 'the word timetable never crossed your mind while all this was going on?'

The driver turned to look directly at him for the first time. The agent took a step back. Here was a man who had hang‑glided over Hell.

'You tell them,' said the driver, and walked away.

The agent stared after him, and then walked around to the door.

A small man with a hunted look climbed out, dragging a huge fat man behind him and gabbling urgently in a language the agent didn't understand.

And then the agent was left alone with a coach and horses and an expanding circle of hurrying passengers.

He opened the door and peered inside.

'Good morning, mister,' said Nanny Ogg.

He looked, in some puzzlement, from her to Granny Weatherwax.

'Is everything all right, ladies?'

'Very nice journey,' said Nanny Ogg, taking his arm. 'We shall def'nitly patronize you another time.'

'The driver seemed to think there was a problem...,

'Problem?' said Granny. 'I didn't notice any problems. Did you, Gytha?'

'He could've been a bit quicker fetching the ladder,' said Nanny, climbing down. 'And I'm sure he muttered something under his breath that time we stopped to admire the view. But I'm prepared to be gracious about it.'

'You stopped to admire the view?' said the agent. 'When?'

'Oh, several times,' said Nanny. 'No sense in rushing around the whole time, is there? More haste less speed, ekcetra. Could you point us in the direction of Elm Street? Only we've lodgings at Mrs Palm's. Our Nev speaks highly of the place, he says no one ever looked for him there...'

The agent stepped back, as people generally did in the face of Nanny's pump‑action chatter.

'Elm Street?' he stuttered. 'But... respectable ladies shouldn't go there...'

Nanny patted him on the shoulder. 'That's good,' she said. 'That way we won't run into anyone we know.'

As Granny walked past the horses they tried to hide behind the coach.

Bucket smiled brightly. There were little beads of sweat around the edges of his face.

'Ah, Perdita,' he said. 'Do sit down, lass. Er. You are enjoying your time with us so far?'

'Yes, thank you, Mr Bucket,' said Agnes dutifully. 'Good. That's good. Isn't that good, Mr Salzella? Don't you think that's good, Dr Undershaft?'

Agnes looked at the three worried faces.

'We're all very pleased,' said Mr Bucket. 'And, er, well, we have an amazing offer for you which I'm sure will help you to enjoy it even more.'

Agnes watched the assembled faces. 'Yes?' she said guardedly.

'I know you, er, have only been with us hardly any time but we have decided to, er'‑ Bucket swallowed, and glanced at the other two for moral support–'let you sing the part of Iodine in tonight's production of La Triviata.'

'Yes?'

'Um. It isn't the major role but of course it does include the famous "Departure" aria...'

'Oh. Yes?'

'Er... there is, er... that is, er...' Bucket gave up and looked helplessly at his director of music. 'Mr Salzella?'

Salzella leaned forward. 'What in fact we would like you to do... Perdita... is sing the role, indeed, but not, in fact... play the role.'

Agnes listened while they explained. She'd stand in the chorus, just behind Christine. Christine would be told to sing very softly. It had been done dozens of times before, Salzella explained. It was done far more often than the audiences ever realized–when singers had a sore throat, or had completely dried, or had turned up so drunk they could barely stand, or, in one notorious instance many years previously, had died in the interval and subsequently sung their famous aria by means of a broom‑handle stuck up their back and their jaw operated with a piece of string.

It wasn't immoral. The show had to go on.

The ring of desperately grinning faces watched her.

I could just walk away, she thought. Walk away from these grinning faces and the mysterious Ghost. They couldn't stop me.

But there's nowhere to walk to except back.

'Yes, er, yes,' she said. 'I'm very... er... but why do it like this? Couldn't I simply take her place and sing the part?'

The men looked at one another, and then all started talking at once.

'Yes, but you see, Christine is... has... more stage experience–'

'–technical grasp–'

'–stage presence–'

'–apparent lyrical ability–'

'–fits the costume–'

Agnes looked down at her big hands. She could feel the blush advancing like a barbarian horde, burning everything as it came.

'We would like you, as it were,' said Bucket, 'to ghost the part...'

'Ghost?' said Agnes.

'It's a stage term,' said Salzella.

'Oh, I see,' said Agnes. 'Yes. Well, of course. I shall certainly do my best.'

'Jolly good,' said Bucket. 'We won't forget this. And I'm certain a very suitable part for you will come along very soon. See Dr Undershaft this afternoon and he will take you through the role.'

'Er. I know it quite well, I think,' said Agnes, uncertainly.

'Really? How?'

'I've been... taking lessons.'

'That is good, lass,' said Mr Bucket. 'Shows keenness. We're very impressed. But see Dr Undershaft in any case...'

Agnes got up and, still looking down, trooped out.

Undershaft sighed and shook his head.

'Poor child,' he said. 'Born too late. Opera used to be just about voices. You know, I remember the days of the great sopranos. Dame Violetta Gigh, Dame Clarissa Extendo... whatever became of them, I sometimes wonder.'

'Didn't the climate change?' said Salzella nastily.

'There goes a figure that should prompt a revival of The Ring of the Nibelungingung,' Undershaft went on. 'Now that was an opera.'