Malien began to climb down. ‘Are you coming, Tiaan?’

‘He’s probably floated away in his balloon already,’ she said miserably.

‘He’d have to gather fuel first and that could take days.’ Malien picked her way down the side of the mountain as if she knew exactly where she was going.

‘Can you sense the amplimet?’

‘I wish I could.’ Malien looked more at ease now. ‘He said the balloon was directly below us and the only fuel was bushes, so it must lie above the tree line. It can’t be more than a few hours down the slope, and a gasbag ten spans high will be visible from a long way. We’ll find him.’

They rested every half-hour. The downhill walking was unexpectedly tiring. On their second stop, as Tiaan was sipping from her flask, there came a monumental crash that shook the rock beneath her. She dropped the flask and scrambled for it as the water gurgled out.

‘What was that?’ The start of an avalanche, she imagined.

‘Icefall,’ said Malien. ‘The glacier runs over a precipice. See, just there. Every so often, the overhanging ice breaks off and falls a thousand spans to the plain.’

They continued, more warily now, though the jumbled rocks here provided plenty of cover. Shortly Malien stopped. ‘Ah, this is hard on my old knees. Creep up onto that rock, Tiaan, and see if you can see anything.’

As Tiaan put her head over the top she saw a black, swelling mushroom, not a third of a league below. ‘It’s just down there,’ she hissed.

Malien climbed up beside her. ‘Ingenious design.’ She shaded her eyes as she stared at the balloon. ‘It looks nearly inflated. We’d better hurry.’

They had not gone far when Tiaan felt a pang in her right temple, a stabbing pain that disappeared as quickly as it had come. She let out a gasp.

Malien stopped at once. ‘What’s the matter?’

‘Just a headache. It’s gone now.’

‘Take some more water,’ Malien advised.

Tiaan took another few sips, though she knew dehydration was not the problem. The pang reminded her of something she had put out of mind a long time ago and did not want to think of now.

A little further on, Malien crouched down between the boulders. ‘I don’t like this,’ she muttered.

‘What is it?’

‘We’re being watched.’

Tiaan scanned the sky. ‘I can’t see a thing.’

‘I can. Come, quickly! There are three of them, and since they’re flying …’ Malien pointed high in the western sky, where Tiaan now discerned a speck, and then two more.

‘Lyrinx!’

FIVE

Nish slammed his way down the stairs, so angry that he dared not speak, lest he take out his frustrations on Ullii. One minute he had succeeded against all the odds and made up for his previous follies. The next he had lost and was good for nothing but to be sent to the front-lines in the hopeless war against the lyrinx. Nish was a proud and ambitious young man who took failure hard.

At the bottom he waited for Ullii. The little seeker moved confidently, despite the mask. Nish never ceased to marvel at her agility. It would be easy to fall off, which would be fatal, but she made not a single misstep.

‘You are sad, Nish,’ she said as she reached the floor, not even out of breath.

Another wonder: how someone who took no exercise could be fitter than he. Nish’s heart was still pounding. ‘What am I going to say to the scrutator, Ullii? He’ll have my head for this.’

‘No one could fight the Matah, Nish.’

Ullii could see the Secret Art in all its forms, as knots in a lattice she created in her mind. It was her special talent, one that made her worth a thousand of him. ‘You were very friendly to her,’ he said harshly, and immediately regretted it. He moderated his tone. ‘What did you see, Ullii?’

‘Matah is old. She is wise and kind, but sad too. She has lost a whole world.’

That was food for thought, though not what he was looking for. ‘What kind of knot does she have, Ullii? Is she a powerful mancer?’

‘Matah is very strong, but she did not use her strength against you. Be careful, Nish.’

‘Ha!’ He headed down the next set of stairs, which were made of alabaster. Nish was no coward, but he knew which battles to fight and which to keep away from.

At the bottom of the next set of stairs, as Nish was consulting his map, Ullii said, ‘I can see Tiaan’s crystal.’

He dropped the map, just managing to catch it before it fluttered through the hole to the next level. He’d assumed that the Aachim would have taken the amplimet. ‘You mean it’s still here?’

‘I can see it.’

She meant in her lattice. Of course she could; she had tracked it all this way from the manufactory. And Tiaan too – Ullii had found her after Tiaan had been missing for months. ‘Where is it? Quick, before they think of it.’

Using the map, it took less than an hour to regain the level where the gate had been made. Nish looked around him. They were in an oval chamber, so large that a good-sized town could have been built inside it, with doors and subsidiary chambers everywhere.

‘Over there.’ Ullii pointed.

Nish ran, looking over his shoulder all the way. There had been too many failures; too many disappointments. Inside the room he was confronted by a strange-looking machine, all glass and crystal, ceramic and wires, ghostly in the dim light. He roved around, trying to make sense of it. Nish did not know what the amplimet looked like. He had never seen it, and the port-all contained dozens of crystals.

‘Ullii?’ he shouted. The sound echoed back and forth for ages. That made him afraid, too.

She came creeping through the door as though trying not to attract attention. Her life was avoiding people. Ullii looked troubled, as if expecting him to yell at her again.

‘I can’t find the amplimet,’ he said softly.

She walked up to the port-all, reached out and took the crystal from a soapstone basket. Nish was amazed that it could be so easy.

She held it in her hand, gazing curiously at it. The amplimet resembled other hedrons Nish had seen in the manufactory, except for one small detail: it glowed.

‘It’s different now.’ Ullii turned it over in her hand.

Alarm choked him up. ‘What do you mean? Is it damaged? Ruined?’

‘No,’ she said softly. ‘It’s just as strong, but it has a different knot.’

‘What can you tell about it?’

She put her hand over the mask as if to block out the least glimmer of light. ‘It is as old as time. It is dreaming at the core of the world.’

Ullii’s pronouncements sometimes bordered on the mystical and he could make no sense of this one. Further questioning proved useless. She could not put what she sensed into words. It did not matter. He had the amplimet, more important than Tiaan now. If he got it back to the manufactory, that would make up for everything.

He reached for it. Snap! It was as if a spiky ball had embedded itself in his palm and was gouging its way through. He wrenched his hand away and the amplimet went flying through the air. ‘No!’ he cried as it fell toward the stone floor.

Unerringly, Ullii snatched it out of the air.

‘I think you’d better carry it,’ Nish said. It felt as if the amplimet had rejected him.

She packed it in her little chest pack and fastened up the straps.

Casting a last look behind him, Nish said, ‘Come on.’ They hurried out of Tirthrax.

After some hours of scrambling down the mountain, Nish realised that Ullii was no longer behind him. He called her name but she did not answer.

He set down his pack, rubbing the palm of his hand. The pain still lingered and the centre of his palm had gone white in the shape of a spiky star. ‘Ullii!’ he roared, and knew that could only make things worse. If she was close by, the racket would make her retreat into herself and he might get nothing out of her for hours. Retracing his path, he found her fifty paces up the slope, huddled under a rock. She did not look up as he approached.