Ullii found an empty room further down, sat in the dark and ate some bread, sharing it with the friend in her pocket. Surprising how comforting she found him. Ullii knew that it was a him.

She considered the spell on the door. For all that she could see the Art in its myriad forms, Ullii was unable to break the simplest spell and this one, she could tell from the convolutions of its knot in her lattice, was not simple. She rotated the lattice, examining the knot from one side and another. Knots could sometimes be undone, but that was dangerous; she might be attacked by what lay hidden inside.

This knot was beyond her, for its tightly woven structure gave no clue to how it was tied underneath. She left it, looking for the dark ball that was Irisis. She was obscured again. The knot now seemed to surround the s.p.a.ce where the crafter was held.

Ullii rotated her lattice again, and from the other side saw an opening, and the crafter within it. It was frustrating to be so close and not be able to get to her. Putting the leftover bread away, she went back to Irisis's door, hoping she might be able to see better from outside. The guard was pacing down the other end of the hall. Ullii could not see see Irisis at all. In frustration, she did something she had never attempted before. She took hold of the lock's knot in the lattice and tried to move it out of the way. Irisis at all. In frustration, she did something she had never attempted before. She took hold of the lock's knot in the lattice and tried to move it out of the way.

She felt the strangest sucking sensation, like a memory from her childhood trying to pull an octopus off a rock. The door creaked.

Footsteps inside the room. 'Who's there?' came Irisis's voice, flat with hopelessness. 'If that's you again, Ghorr '

'It's me. Ullii,' she whispered.

'Ullii? What are you doing?'

'They're going to kill you as soon as the scrutator is gone.'

'I thought so.'

'When does he go?'

'Dawn.'

'Four hours left, then.'

Ullii could not think about the death of her friend finding Myllii occupied her whole mind. 'I need you to help me, Irisis.'

Irisis laughed hollowly. 'I'd be glad to, little seeker. Just name your favour and I will do it. Fly you to the moon? I'm happy to oblige.'

'I want you to find my brother.'

'I didn't know you had one.'

'Myllii is my twin. He was taken away when I was four. He's just like me.'

'Is he now?' said Irisis. 'I wonder if anyone else knows that?'

'Irisis!' Ullii hissed. 'Promise you'll help me find him.'

'Ullii, they're coming for me today. I can't help anyone, even myself.'

'I can open the door,' said Ullii.

The silence from the other side was profound. 'Ullii, if you can get me out of here, I promise I will help find your brother.'

Ullii felt the mouse moving in her pocket. Down the end, the guard pushed back his chair and paced along the hall.

'Guard's coming!' Ullii whispered, scuttling back to the empty room.

He went by, shining his lantern here and there, trying the locked doors. She waited for him to go back the other way. It took a long time.

'Irisis,' she whispered, when the guard had settled back in his chair.

'I'm ready.' Irisis sounded sceptical.

Ullii took hold of the knot. Again that sucking sensation and the lattice blurred in her mind, fragments of the knot waving around her like a handful of worms. The door creaked and groaned. The octopus tightened its grip. She pulled harder but could not budge it.

Ullii sank to the floor. It was not going to work after all. How could she have thought it would?

FIFTY-FIVE.

'Ullii?'

She did not answer. Ullii felt too disheartened. The whole world was against her, even her lattice.

Even her lattice? No, that was her own creation: she could change it however she wanted. Not even this spell that wicked Scrutator Ghorr had made could stop her. How dare he invade her personal s.p.a.ces? She seized hold of the knot and, instead of trying to move it, Ullii held it in place while she shifted the rest of the lattice around it.

The octopus made an agonised squeal as one by one its tentacles tore free. The remaining ones clung more tightly but she controlled the lattice, and with an audible snap the last tentacle let go.

Ullii held her breath. The latch clicked. Irisis slid through the door and was standing beside her. Ullii let go of the knot, which sprang back to where it had been before. The latch clicked again and the door was once more immovably ensorcelled.

'I don't know how you did it,' said Irisis, hugging her gently. 'I'm not sure I want to know. But, thank you.'

Ullii wriggled out of her grip, afraid for the mouse in her pocket.

'Do you know how to get to the air-floater?' Irisis went on.

'No,' Ullii said softly, taking her friend by the hand. 'I have no idea.'

They dared not go up. There were people in the upper halls of Nennifer day and night, and while little Ullii might creep about unseen, Irisis could not. Had Ullii's incomprehensible interference with the door set off Ghorr's alarm? There was no sign of it.

'We'll have to go down, I think,' she said to the seeker. 'Perhaps if we were to look for a privy outlet.'

Ullii gave her a disgusted glare. Even with noseplugs in, she could never escape through such a stinking place.

'Perhaps not,' said Irisis. 'A drainage pipe, then.'

Ullii was not good at finding that kind of thing. After several hours of searching, during which time Irisis's anxiety grew alarmingly, she found the cleaning eye in a conduit that led from the barracks bathhouse above. She lifted it off. The inside was an oval of rough earthenware about the height of a child of ten. Ullii would have to bow her head. Irisis would need to walk doubled over.

Ullii eyed it dubiously. It stank of stagnant water and something else, sweetly rotting. She shook her head. 'Not going in there.'

'We've only an hour till dawn, Ullii. If we don't get to the air-floater before the scrutator goes, we might as well go back and lock ourselves in. There's no other way out of Nennifer.'

'Don't like this way,' Ullii muttered.

Irisis did not either. She imagined it discharged directly over the cliff and when they got to the end there would be no way of getting out. Still, better that than Ghorr's mercies.

'Ghorr will soon be looking for me. We've got to get out of sight, if we are are to find your brother.' to find your brother.'

Irisis had purloined a lantern. She lowered herself into the conduit and Ullii had to follow. Settling the cover back in place, Irisis held up the lantern. The water, a trickle in the bottom of the pipe, flowed back behind her.

'That way.'

The pipe wandered all over the place. Smaller pipes frequently joined it. It did not get any bigger and soon her back was aching. Something trailed across her head as she shuffled along.

The top of the pipe was festooned with grey jelly-like stuff in which matted hairs, bits of toenails and clots and sc.u.m of repulsive origin had been caught. More of the gelatinous growth had formed, or congealed, around it. All this has come from people's bodies in the bathhouses, Irisis thought with a shiver of disgust. And what else that we can't see?

The smell grew stronger. Irisis stumbled into a pool of still water where the pipe had subsided. Brown sludge coated her boots. The smell was revolting. Ullii gagged.

After a long interval they began to smell fresh air, carried by a night breeze up the pipe. 'Not far now.'

Ullii grunted.

They reached it suddenly, an oval circle barely lighter than the blackness inside. Dawn was not far off.

'Careful,' said Irisis. 'If you slip ...'

She needed the warning more than the seeker did. Ullii was surefooted and she never took risks. Irisis edged down to the opening and was glad she had. The floor of the pipe here was covered in a slippery green growth. The pipe ended at the cliff. The lantern light revealed the stream of water arching down, beyond sight and sound, into the Desolation Sink.

She edged up the side of the pipe, where it was dry, and peered out. The cliff towered above her, almost sheer. There was nothing that resembled a ledge or handhold. Without ropes and irons, it was unclimbable.

'I'm sorry, Ullii. We can't get out.'

Ullii crept up beside her. 'Xervish is going.'

'I can't see him.' Irisis craned her head around. Way back to her left a shadow was rising above the escarpment. It was the air-floater. 'Flydd! Flydd!' She waved the lantern as vigorously as she could. 'Flydd.'

The air-floater kept rising. Ullii shrank back into the drain with her hands up over her face, as if to ward something off.

'What is it, Ullii? What's the matter?'

'Ghorr!'

Irisis put down the lantern and looked up. Figures moved on the edge. Someone was pointing down at the entrance to the pipe. The lantern must have been perfectly visible against the shadowed rock.

'They're coming,' said Ullii. 'I'll never find Myllii now.'

'By this time tonight, neither of us will have to worry about that,' Irisis muttered. She waved the lantern again, hoping that Flydd might be able to see it, though it was hard to imagine what he could do.

'Ullii, is there any way you can signal the air-floater with your lattice?' On the way, Ullii had attempted to explain what she'd done. It had made no sense to Irisis.

'No one else can see it,' said Ullii, as if she were talking to a fool.

'What if you moved it around Flydd, the way you got me out of my cell?' Irisis knew she was talking nonsense as soon as the words left her mouth.

'Can't,' said Ullii, quivering. She looked like she was going to have one of her fits.

'Where is your little mouse?'

Ullii felt in her pocket and some of the strain faded. 'He's here.'

'Can I see him?'

Ullii brought him out. The little creature gazed steadily at her. Its whiskers twitched.

'He's smiling at you,' Irisis said. 'What a brave little mouse he is.'

Ullii managed a smile of her own as she returned the mouse to her pocket.

People were running above, along the cliff edge, calling out to each other. 'Down there,' Irisis heard someone shout.

'Do you think you can do anything anything to call Flydd?' Irisis said softly. to call Flydd?' Irisis said softly.

'Don't know how.'

'Look in your lattice, Ullii. Can you see the air-floater, and Xervish?'

'Yes.'

Why was the seeker so changeable and difficult? 'Do what you did to the door. It may make Flydd realise we're here.'

'Won't,' Ullii said. 'You don't know the lattice.'

'Please try.'

'Can't.'

Ullii's talent was as stubborn as she was. Maybe it, like her courage, appeared only when she had no other option. That was not necessarily when she was threatened; in such cases she normally put her head in the sand. But when someone she cared deeply about was threatened, Ullii could be a tiger. Was her lost brother the key?

'Where is your brother, Ullii?'

'Don't know,' she said sullenly. 'Left me. Hate him.'

'You don't hate him,' said Irisis, waving the lantern with her free hand. The air-floater rose ever higher, well out over the depression of Kalithras. In a few minutes it would be beyond sight or signal. And minutes after that, Ghorr would have soldiers down here on ropes. 'You miss him terribly.'

'Don't!'

'If Myllii has your talent,' Irisis chose her words very carefully, 'the scrutators might be using him too, now that he is grown up. He might be in danger.'

Ullii gasped and shook her head from side to side.

'If we can just get away, in the air-floater we can fly across half of Lauralin. If he's in the east, you'll surely see him in your lattice.'