Alchymist

'Are you saying that some of the nodes might explode, as at Snizort?' asked Tiaan.

'That's one possibility, and the explosive force could spread to the nodes surrounding them,' said Malien. 'Or the driving forces themselves could become unbalanced, tearing the crust of the world apart. No one knows enough geomancy to tell.'

'Is there any way to find out.'

'That's what we've been talking about.'

'Bilfis and I have put our concerns to the Aachim Syndic,' said Malien the following morning. 'That last earth trembler alarmed them, so we turned the screws. My people aren't happy, but they've agreed to give us what we want, in return for the secret of flight. They want to build their own thapters.'

'Is that wise?' said Tiaan, but regretted it as soon as she'd spoken. She had no right to question Malien.

'I had nothing else to bargain with.'

'What are they giving in return?'

'Everything they know about nodes.'

'You might have demanded that by right,' said Bilfis.

'And they might have stalled me for months,' said Malien. This way we can begin in a week.'

'To do what?' said Tiaan.

'To map the nodes near Stassor, so we can see how they're being affected.'

'Can I come too?' Tiaan was used to being busy but there would be nothing for her to do here. 'I'll do anything that needs doing.'

'I want you to come,' said Malien. 'Indeed, I can't do it without you.'

By the time the Aachim had released the thapter and made a start on building their own, weeks later, Tiaan, Malien and a mapmaker had gone through the archives and produced a series of charts of the mountains surrounding Stassor. These showed all nodes the Aachim knew about.

There were many kinds: weak nodes and strong, steady ones and those whose fields fluctuated wildly or unpre-dictably, or flared up only to die away to nothing. There were occasional double nodes and one triple – which Malien was too perilous to approach – as well as two anti-nodes which were even more dangerous. The anti-nodes may have grown by cannibalising the fields of others, but no one had ever dared approach close enough to find out.

Only then did Tiaan and Malien sit down, with a small glass of the Aachim liquor called syspial in hand, and consider their work. The nodes were not evenly distributed but fell into patterns, groups and aggregations, which in turn were organised into provinces. These often corresponded to geographic features like mountain chains, volcanoes, cliffs or ridges. Not always, though – some nodes were not related to anything on the surface of the earth.

Tiaan took a sip of her drink, which was the colour and flavour of sweet blackberry liqueur, but stingingly spicy-hot. 'Where do nodes come from, anyway?'

'No one has any idea,' said Malien, 'except, possibly, your friend Gilhaelith. He knows more about the natural philosophy of the world than anyone.'

'It's been his life's work.' She wondered if Gilhaelith was still alive; and if so, what he was up to.

The next step was to go out at night in the thapter, mapping the fields of the nodes while Malien flew a course by the moon or the stars, and Bilfis plotted the fields on the chart. Tiaan was forced to use the amplimet, which was always risky now. Once or twice she flew the thapter, and had to use the crystal for that as well. She did not have the talent to fly the thapter the way Malien did.

They spent a tedious month on this work, by which time they had created a map of the area within forty leagues of Stassor. It was very rough, but to refine it would have taken months more, for they learned something new every day: new fields and new nodes, even new kinds of nodes. Tiaan wished she understood them.

By that time, two teams, each one comprising hundreds of Aachim, working day and night, had built a pair of thapters, though only the second of them remained at Stassor: the other machine had flown west a fortnight ago. Tiaan suspected it had been sent on an embassy to Vithis, and she was not looking forward to its return.

The following morning she was in the front meeting room when there was a screeching whine outside and the missing thapter shot past a transparent section of wall, heading for the compressed-ice platform.

'Who's that?' Malien said sharply.

'Tormil,' said Harjax. 'I sent him to make contact with Vithis, and from his haste I'd say he has.' He bent his head to his papers.

Malien's left hand gripped Tiaan's knee under the table and squeezed hard – a warning. She wrote a note on a scrap of paper and passed it to Tiaan. 'Would you take this to Bilfis, please? He's in his room.'

'Of course,' said Tiaan. She rose, bowing to the Aachim, who ignored her as usual, and hurried out.

The operator was in such haste that he had flown his thapter right up to the cubular doors, which were spreading apart as Tiaan went by. He threw himself over the side, almost falling in his haste.

Tiaan made her way to Bilfis's room, and found him sitting at the table, poring over his field maps.

'Malien asked me to give you this.' She passed him the paper.

He scanned it, thrust it into his pocket, rolled the maps and sprang up. 'Take these to Malien's thapter. Act normally. Have you your amplimet?'

'Always.'

Scooping gear from the table, he thrust it into a small pack. A pile on the bed followed it and he tossed the pack over his shoulder.

'What's the matter?' said Tiaan.

'Don't ask stupid questions, just go!'

That alarmed her, for the Aachim of Stassor might be remote, condescending or aloof, but they were invariably polite.

'Walk calmly,' he went on. 'Don't attract attention.'

Easy to say, but she didn't know if he was helping or kidnapping her. Trust Malien, she told herself. Tiaan did her best to act normally, though it must have been obvious, had the passing Aachim glanced at her, that she was under a strain. Fortunately they took no more notice of her than at any other time.

They'd trudged the corridors and were halfway across the ice pavement outside when someone called out, 'Bilfis, can you spare me a moment?'

'Keep going, Tiaan,' Bilfis said softly. 'Get into the thapter and make it ready for flight. Don't get out no matter what happens, or what I say.' He turned. 'Harjax? I'm just checking some of the maps I left in the thapter.'

'Would you bring the old human back for interrogation, please?'

'Certainly. Tiaan,' he called, 'fetch the maps from the thapter, if you would.'

Tiaan risked a glance over her shoulder as she climbed the side. Harjax stood uncertainly outside the cubular doors, a victim of indecision and Aachim politeness. Tiaan slipped in, put the maps into their racks, carefully inserted the amplimet and made all ready. She felt ill. She'd only flown this thapter a couple of times, and then briefly. Its controls, different from those of her original thapter, could be temperamental. She prayed for a steady hand and a strong stomach.

'Would you fetch her please, Bilfis,' called Harjax, trying to be commanding without alerting his quarry. 'It's rather important.'

'Of course,' said Bilfis, 'if it's so urgent.' He strolled towards the thapter, a picture of unconcern. As he climbed the side he said quietly to Tiaan, 'Ready?'

'Yes.'

'Go, as fast as you possibly can. Fly around the side, then back to the east-facing door. Malien will be waiting there.' He jumped in.

The thapter sprang to life. Tiaan mentally worked the controls, praying she had them right.

Harjax, belatedly realising that something was wrong, began to run across the paving.

'Come on!' Bilfis snapped.

She jerked and twisted the yoke at the same time. The thapter lifted sharply, spinning on its axis, front down, so quickly that she couldn't see where she was going. Harjax sprang out of the way, shouted to the guards outside the doors but again hesitated, unwilling to fire on his own.

Tiaan turned the yoke back, a fraction too far, for the thapter now tumbled end for end while it was still spinning. At least it was slowly gaining height, though it was heading straight for the cubular doors.