'Oh, I understand,' she said. 'This is some sort of test, is it? It is, isn't it? We're worried, so fear makes it a deep gorge. Perdita's always confident, so she hardly notices it...'

'I'd like to notice it's there,' said Magrat. 'It's a bridge.'

'We're wasting time,' said Agnes. She strode out over the slabs of stone and stopped halfway.

'Rocks a bit, but it's not too bad,' she called back. 'You just have to-'

The slab shifted under her, and tipped her off.

She flung out her hands and caught the edge of the stone by sheer luck. But, strong though her fingers were, a lot of Agnes was penduluming underneath.

She looked down. She didn't want to, but it was a direction occupying a lot of the world.

The water's about a foot below you, it really is, said Perdita. All you have to do is drop, and you'd be good at that...

Agnes looked down again. The drop was so long that probably no one would hear the splash. It didn't just look deep, it felt deep. Clammy air rose around her. She could feel the sucking emptiness under her feet.

'Magrat threw a stone down there!' she hissed.

Yes, and I saw it fall a few inches.

'Now, I'm lyin' flat and Magrat's holdin' on to my legs,' said Nanny Ogg conversationally, right above her. 'I'm going to grab your wrists and, you know, I reckon if you swings a little sideways you ought to get your foot on one of the stone pillars and you'll be right as ninepence.'

'You don't have to talk to me as if I'm some kind of frightened idiot!' snapped Agnes.

'Just tryin' to be pleasant.'

'I can't move my hands!'

'Yes, you can. See, I've got your arm now.'

'I can't move my hands!'

'Don't rush, we've got all day,' said Nanny. 'Whenever you're ready.'

Agnes hung for a while. She couldn't even sense her hands now. That presumably meant that she wouldn't feel it when her grip slipped.

The stones groaned.

'Br... Nanny?'

,Yep?,

'Can you talk to me a bit more as if I'm some kind of frightened idiot?'

'Okay.'

'Er... why do they say right as ninepence"? As opposed to, say, tenpence?'

'Interestin'. Maybe it's-'

'And can you speak up? Perdita's shouting at me that if I drop eighteen inches I'll be standing in the stream!'

'Do you think she's right?'

'Not about the eighteen inches!'

The bridge creaked.

'People seldom are,' said Nanny. 'Are you getting anywhere, dear? Only I can't lift you up, you see. And my arms are going numb, too.'

'I can't reach the pillar!'

'Then let go,' said Magrat, from somewhere behind Nanny.

'Magrat!' snapped Nanny.

'Well, perhaps it is only a little stream to Perdita. Gnarly ground can be two things at the same time, can't it? So if that's how she sees it... well, can't you let her get on with it? Let her sort it out. Can't you let her take over?'

'She only does that when I'm really under stress! Shut up!'

'I only-'

'Not you, her! Oh, no-'

Her left hand, white and almost numb, pulled itself off the stone and out of Nanny's grip.

'Don't let her do this to us!' Agnes shrieked. 'I'll fall hundreds of feet on to sharp rocks!'

'Yes, but since you're going to do that anyway, anything's worth a try, isn't it?' said Nanny. 'I should shut your eyes, if I was you-'

The right hand came loose.

Agnes shut her eyes. She fell.

Perdita opened her eyes. She was standing in the stream.

'Damn!' And Agnes would never say 'damn', which was why Perdita did so at every suitable occasion.

She reached up to the slab just above her, got a grip, and hauled herself up. Then, catching sight of Nanny Ogg's expression, she jerked her hands around into a new position and kicked her legs up.

That stupid Agnes never realizes how strong she is, Perdita thought. There's all these muscles she's afraid of using...

She pushed gently until her toes pointed at the sky and she was doing a handstand on the edge. The effect, she felt, was spoilt by her skirt falling over her eyes.

'You've still got that tear in yer knickers,' said Nanny sharply.

Perdita flicked herself on to her feet.

Magrat had her eyes tight shut. 'She didn't do a handstand on the edge, did she?'

'She did,' said Nanny. 'Now then, A- Perdita, stop that showing off, we've wasted too much time. Let Agnes have the body back, you know it's hers really.'

Perdita did a cartwheel. 'This body's wasted on her,' she said. 'And you should see the stuff she eats! Do you know she's still got two shelves full of soft toys? And dolls? And she wonders why she can't get along with boys!'

'Nothing like being stared at by a teddybear to put a young man off his stroke,' said Nanny Ogg. 'Remember old Mrs Sleeves, Magrat? Used to need two of us when she had one of her nasty turns.'

'What's that got to do with toys?' said Perdita suspiciously.

'And what's it- Oh, yes,' said Magrat.

'Now, I recall that old bellringer down in Ohulan,' said Nanny, leading the way. 'He had no fewer than seven personalities in his head. Three of 'em were women and four of 'em were men. Poor old chap. He said he was always the odd one out. He said they let him get on with all the work and the breathin' and eatin' and they had all the fun. Remember? He said it was hellish when he had a drink and they all started fightin' for a tastebud. Sometimes he couldn't hear himself think in his own head, he said- Now! Now! Now!'

Agnes opened her eyes. Her jaw hurt.

Nanny Ogg was peering at her closely, while rubbing some feeling back into her wrist. From a couple of inches away her face looked like a friendly pile of elderly laundry.

'Yes, that's Agnes,' she said, standing back. 'Her face goes sharper when it's the other one. See? I told you she'd be the one that came back. She's got more practice.'

Magrat let go of her arms. Agnes rubbed her chin.

'That hurt,' she said reproachfully.

'Just a bit of tough love,' said Nanny. 'Can't have that Perdita running around at a time like this.'

'You just sort of grabbed the bridge and came right back up,' said Magrat.

'I felt her stand on the ground!' said Agnes.

'And that too, then,' said Nanny. 'Come on. Not far now. Sometimes. And let's just take it easy, shall we? Some of us might have further to fall than others.'

They edged forward, despite an increasingly insistent voice in Agnes's head that kept telling her she was being a stupid coward and of course she wouldn't be hurt. She tried to ignore it.

The caves that Agnes remembered hadn't been much more than rock overhangs. These were caverns. The difference is basically one of rugged and poetic grandeur. These had a lot of both.

'Gnarly ground's a bit like icebergs,' said Nanny, leading them up a little gully to one of the largest.

'Nine-tenths of it is under water?' said Agnes. Her chin still hurt.

'There's more to it than meets the eye, I mean.'

'There's someone there!' said Magrat.

'Oh, that's the witch,' said Nanny. 'She's not a problem.'

Light from the entrance fell on a hunched figure, sitting among pools of water. Closer to, it looked like a statue, and perhaps not quite as human as the eye at first suggested. Water glistened on it; drops formed on the end of the long hooked nose and fell into a pool with the occasional plink.

'I come up here with a young wizard once, when I was a girl,' said Nanny. 'He liked nothing so much as bashing at rocks with his little hammer... well, almost nothing,' she added, with a smile towards the past and then a happy sigh. 'He said the witch was just a lot of of stuff from the rocks, left there by the water drippin'. But my granny said it was a witch that sat up here to think about some big spell, and she turned to stone. Person'ly, I keep an open mind.'

'It's a long way to bring someone,' said Agnes.