Something occurred to him. Spitting the rest of the soup back into the bowl, he took out the piece of salt and examined it in the dim light. It had crystal faces.

Salt was of little use in geomancy unless the crystals were perfectly formed, and even then it could take little power. But it was all he had. Using a tine of his fork, he picked away at the chunk of rock salt, trying to separate it into one or more crystals he could use. Gilhaelith was exquisitely careful, for the tiniest scratch on a crystal face would ruin it for mancery. He quite lost himself in his work, taking an hour to remove a flawed crystal as small as a grain of wheat.

The night passed, and the following morning. Gilhaelith laboured on, now holding the remaining crystals in a rag torn from his shirt, for even the moisture from his fingers would damage them. By the middle of the afternoon the last dross cleaved away and he had a single, perfect cube of salt, transparent and with a faint yellow tinge. He might be able to work some minor magic with it — slip the lock, douse the lights in the corridor, possibly even put the nearby guards to sleep, but that would be its limit.

Wiping a patch of floor, he set his forgotten dinner on it and carefully placed the crystal in the centre of the tray. A pair of guards passed down the corridor, talking quietly. Gilhaelith dropped his rag over the crystal and lay back on the palliasse, clenching his fists against the tension. The guards were watchful and intelligent. Anything might arouse their suspicion.

They looked in, saw nothing amiss and went by. He began at once. If the crystal did work, he would have to get it right first time, for Yggur would allow no second chances. It might be better to wait until he'd gone to Nennifer. No, Yggur could have special plans for Gilhaelith in his absence. Do it now.

Gilhaelith ever so gently drew power into the crystal — not enough to reveal himself, but enough for him to sense any auras elsewhere in Fiz Gorgo. They could be due to mancers or other sources of the Art best avoided. He picked up several: Yggur and Malien close together, Flydd elsewhere, and various devices presumably in Yggur's quarters. He wasn't worried about them, but something larger and more tenuous, further out, did bother him.

It was like a filmy cloud surrounding Fiz Gorgo, and he could detect nothing beyond it. It must be a protection of some sort, to keep the outside world from spying or even noticing that there were mancers here, or to keep people in.

Gilhaelith withdrew, considering. Invisible to sight and touch the protection might be, nonetheless it could prevent him from escaping. He probed it tentatively, to discover how it had been made, and its strength. To his surprise it did not resist him — it was set to protect from the outside, not from within.

He took a little more power but the phantom fragments stung his brain like sparklers. He lost control for a second and his probe went right through the protection, burning a small opening like an eye. He withdrew hastily and it closed over again. Too hastily! A final surge of power zipped through the cubic crystal, cleaving it down the middle. He cursed, crushed it underfoot and threw himself on the bed in disgust.

He'd have to find another way.

Three times now, Ullii had thought she'd found them. Three times she'd rebuilt the lattice to try to uncover what had been hidden, but without success. Something was out there, a long way south, but she could neither pinpoint nor identify it. It pleased her that her failure was frustrating Ghorr and Fusshte, though she dreaded being punished for it.

'I don't like it,' said Ghorr. 'Is it deliberate, do you think?'

Ullii could not answer that. She simply saw what was in her lattice. She had no idea what was behind it.

In the mid-afternoon the fleet had set down on the plain south of Flumen, by a main road now partly reclaimed by grass and scrub, while he called the other scrutators into a conference. They spent an hour at it, all the while consulting instruments of their own, as Ullii squatted in the shadows waiting on their pleasure.

'They're hiding, but I don't think it's from as,' Ghorr concluded. 'Nothing suggests that they know we're coming, and we must strive to keep it that way. It's just a general cloaking, to conceal them from the lyrinx. We'll continue, more carefully.'

He turned to the seeker. 'Ullii, we are getting closer, are we not?'

'I can't tell.' Fear grew in her: fear that the lattice was failing, for it was harder to see each time; and fear of Ghorr and the scrutators, and what they would do once they'd captured their quarry and had no further need of her. She had to protect herself, which meant finding someone to look after her. But no one on these air-dreadnoughts cared if she lived or died, or how much she suffered.

She idly scanned her lattice, started, and again Ghorr noticed her flinch.

'Yes, Seeker?'

She didn't want to answer, but she had to. 'J — just then, for a second, I saw an opening like an eye.'

An opening? In what?'

'I can't tell.'

'What else did you see? What was in the opening?'

'A strange knot.'

'Tell us more, Seeker' said Fusshte.

'The knot shone out like someone peering from a hole cut in a cloud, then disappeared.'

'Did it now? Whose knot was it?'

'I don't know. It was strange but very strong. A mancer's knot.'

'Really?' he said. 'The cloud must be some kind of protection. That gives me an idea, Seeker.’

She waited numbly for his orders.

'Do you remember how you got Irisis out of her prison cell in Nennifer, Ullii?'

Of course she did. It was only the second brave thing she had done in her life. 'Yes,' she whispered.

'You held the magicked lock's knot in place and rotated the rest of your lattice around it, and that opened the door without breaking my magic.’

'Yes.' She felt faint just talking to him.

'What if you were to do that now? Hold that knot, what you remember of it, in place and redraw your lattice from the other side.'

'I'll try,' she said softly, 'though I don't see what—'

'Just do it,' he said. 'I won't punish you if you fail — only if you don't try hard enough.'

Ullii was so afraid that, at first, she could not see her lattice at all. When it finally appeared, more pale and ghostly than she had ever seen it, she recognised nothing but the bright knots made by Ghorr's scrutators and mancers, and the controllers that powered the air-dreadnoughts. Ghorr had to calm her, as unpleasant an operation as she could imagine, before she recovered the knot.

You have it!' said Ghorr, dark eyes gleaming. 'Now, make your lattice anew, looking the other way.'

Ullii closed her eyes and put her hands over the goggles for good measure. Holding the image of that strange knot, she dissolved the rest of the lattice, turned the knot around in her mind and began to redraw the lattice from the other per-spective. It became sprinkled with blotches, smudges and knots, near and far. The blotches were objects that used some form of the Art like controllers. The smudges were fields gen-erated by nodes, while the knots indicated people who had some talent for the Art. A dim smudge was the cloud of protection but she could see through it now. Inside, she recognised several knots. Irisis was in the centre. Close by, Ullii saw Fyn-Mah, and Flydd, and other knots too, some very strong.

'I've found them.' She took her hands away from the goggles.

Ghorr's head swung around and his eyes glowed like broken glass melting from underneath. 'Where?' he hissed.

Her finger traced a line along the map until it encountered a dot with two small words beside it: Fiz Gorgo. 'There.' Ghorr purred and called the scrutators. 'To the air! We can be there by three in the morning. Plan number seven.'