*Not by crashing and losing a leg, I hope.'

*No. Here's hoping, anyway.'

It seemed to take them hours to reach the top. The stairs were steep and they took turns at being fore or aft to preserve their backs. Rest stops came with increasing frequency. Only as they neared the end of the stairwell did Chu explain that there was another way to get there, one involving counterweights and pulleys that took no more energy than crossing a room.

*So why are we bothering with all this? Why nearly kill ourselves when it's not necessary?'

*I think it's necessary. Consider it an initiation. You need to be acutely aware of how high you are before you take off. Otherwise you might get careless. I want you nice and primed before I put my life in your hands.'

*I thought it was the other way around.'

*You're the one with the licence, stone-boy.'

*But you'll be doing the actual flying, right?'

*It doesn't work like that,' she said a third time.

He felt like a kite on a line, tugged and jerked about by her slim hand. *Isn't it about time you told me how it does work?'

*Much easier to show than tell. Be patient. We'll be there soon.'

He didn't clarify the point that he wasn't so much impatient as terrified. It seemed a perfectly appropriate response to his situation.

Fading sunlight greeted them when they reached the top. He staggered out of the stairwell and put his end of the wing down on the ground to catch his breath. They were standing at the rear of the uppermost platform, looking south. To his left, nightfall turned the sky orange over a forest of spires, chimneys and onion-shaped roofs. Observatory Tower out-reached all of them, giving the skyline a focus and the flyers a ready point of reference. Silhouetted against the sunset were a number of gliding shapes as miners returned to the city from the Divide, sweeping in to land on their level or one of the others below. The air was full of the sound of voices, the rattle of wings, and the clatter of thin, hook-like tools with which he a.s.sumed they s.n.a.t.c.hed prizes from the Divide floor.

*It's going to be dark soon,' he said, feeling the wind stiffen around him.

*The best time to fly.' Chu secured the straps of her uniform. *Less traffic'

*We won't see much.'

*That's not our intention, this first time. It's just a practice run. Tomorrow we do the real work.'

If we're still alive, Skender thought. Marginally rested, he bent down to pick up his end. *Let's get this over with.'

She punched him on the shoulder. *Not exactly the spirit I'm looking for, but it'll do.'

Together they carried their awkward burden to a clear area of the platform well away from the other flyers. There the two of them unfurled the wing and made sure everything was secure. Chu checked the repaired struts and fussed with the harnesses. As the sky grew darker, her adjustments became progressively finer until he could barely see what changes she was making.

*Well, well,' said a voice from behind him. *This is an unexpected development.'

Skender let go of the wing and turned to see a leather-clad flyer standing nearby. He was a full head taller than Skender and elegantly muscled with it. His blue uniform hugged his body, except where it hung open down his chest, revealing an extensive network of angular black tattoos crisscrossing his skin. His hands were also tattooed, as was his face behind the beginnings of a reddish beard. Skender had rarely seen such extensive work, even on the most charm-mad Stone Mages. His eyes were a deep, impenetrable black.

Chu looked up from her work, then glanced pointedly back down. *What do you want, Kazzo?'

*Nothing, Chu. I'm just concerned for your wellbeing. The last time you went flying, you ended up impersonating a drowned cat being pulled out of a reservoir. Looks like you've landed on your feet. Does this mean you're back for good?'

*Only so long as it takes me to get out of your face.'

Kazzo laughed. *Perhaps you should try the mountains, if you're looking for easier nests. Do send us a clutch of eggs when you get there.'

*You need them that badly, do you?'

*That's not what Liris says.'

Skender could only see Chu's face in profile, but the effect Kazzo's remark had on her was p.r.o.nounced. She froze in mid-movement and her jaw muscles worked.

*I think you should leave her alone,' said Skender, hearing the words as they came out of his mouth but not believing he was actually saying them.

*You're a long way from home, stone-boy,' said Kazzo with a scornful glance. *What you think isn't relevant.'

Skender had seen Kazzo's type plenty of times, but had yet to find a good way to deal with them. Standing up to them would only start a fight, while backing down would set a dangerous precedent, one the bully would call on every time they met.

Skender wiped his hands on his robes and didn't look away.

*That's Stone Mage to you, Kazzo Niclais,' he said.

The tall miner performed a barely perceptible double take. Skender could practically hear the cogs turning as Kazzo considered calling his bluff. Laure might be a long way from the deeper deserts, but a Mage was not someone to lock horns with lightly. The Interior possessed considerable political weight even where the Change was weakest.

A young woman on the far side of the platform called Kazzo's name. The tall miner broke their stare and flashed a diffident wave at her. Skender wondered if he saw a hint of relief in his eyes.

*Yes, well,' Kazzo drawled, *I'll leave you two lovebirds to get better acquainted. You won't have long before the ground takes you. Better make it count.'

He swaggered away, affecting utter unconcern. Skender let out the breath he was holding and wiped a hand across his forehead. Lovebirds?

Then Chu was standing next to him, watching Kazzo's retreating back.

*I can fight my own battles,' she said, *but thank you, anyway.'

He looked at her, and was surprised to see something very much like tears in her eyes.

*You're welcome,' he said.

*Whatever. Now, come here,' she said, tugging him to the far side of the wing. *The waiting is finally over.'

She forced him to stand still while she raised the wing into position at his back. As the leather straps of the harness fastened over his shoulders and around his waist, he was dismayed at the thought of his own weight. How he and the wing - and Chu - were supposed to stay aloft for even a second was beyond him. He felt tired and irritated. And very, very heavy.

Some things are simply more important, his father had said. Finding his mother was more important than his fear, he told himself. Even if he died trying.

They didn't talk about Kazzo. They didn't talk at all.

When the harness was in place, she stepped back to look at him. With a water bottle tied around his neck he felt like a very ugly moth. The wing extended in a rigid sheet behind his back, vanishing to the periphery of his vision when he looked directly forward. His arms hung at his sides. He had expected them to be lashed to the underside of the wing in a grotesque parody of bird-flight, but he was spared that indignity. As promised, his robes were firmly strapped where they wouldn't get in the way. A cool breeze trickled up his left leg.

*Remarkable,' she said. *You look almost convincing.' Someone whistled from the far side of the platform. Laughter smattered. *Ignore those idiots. Here's where you find out why I can't fly you in this wing.' She reached into her back pocket and produced the envelope she had stashed there. *This is your licence. Only you can use it.'

*What difference does it make whose name is on the piece of paper?'

*It's not just paper.' Chu pulled the papers out, selected one, and put the others back in her pocket. She held up the one she had kept so he could see. It was black, not white, and looked more like cured hide than paper. *This is what matters. The rest is just bureaucracy. Hold still.'

She came closer and pulled the neck of his robe wide. He tried not to flinch, realising then how naive he'd been. Flying wasn't as simple as sticking on a wing and jumping into the air. If it was, people would be doing it whenever and wherever they felt like it. They would be launching in droves from the stone windowsills and verandahs of the Keep, swooping like eagles among his home's stony crags.

He turned his face away as she pressed the black sheet to his chest. It was cool and moist against his skin. A tingle of the Change rushed through his veins. Chu stared fixedly at him, at whatever transformation began in him.

The tingling became stronger. He felt as though ants with red-hot feet were crawling out of his chest and spreading across the rest of his body, burning him where they pa.s.sed. His muscles tensed. Breath hissed between his teeth. Chu gripped his shoulders and held him steady. He couldn't make his arms work properly to hold her in return.

One glimpse of his hands told him what was happening. Sinuous black lines spread down both wrists, wriggling and twisting like streamers in a gale. They crossed and re-crossed on his palms, coiled around his fingers, flexed like mathematical grids on his knuckles.

Something black slid across his vision, snuffing out the world. He cried out at the sudden blindness, giving in to a subtle, insidious terror: that he had been too trusting; that Chu meant him ill; that his mother would be lost because he was trapped in a malevolent web that he had willingly walked into. He cursed himself for letting the yadachi take blood from him so easily. Surely he could have found another way into the city. Who knew what dreadful hex they had placed on him as a result?

Then Chu's breath was in his ear. *Relax,' she whispered. *Almost there.'

Despite his doubts, he believed her. Whatever she had done to him, it had to be for a reason. She needed him to fly in order to get her licence back, and he certainly wouldn't be able to fly without eyes. That meant his blindness was temporary. All he had to do was wait it out and see what the charm left him with - what new ability he would have that would make flying a possibility.

He concentrated on the smell of her - rich and feminine and earthy - and counted his heartbeats as the manifold lines wrapped themselves around him.

Forty-two. Forty-three. Forty-four ...

When his eyes cleared, he could see the wind.

The Tracker.

*Warden and Mage have ever been at odds. Their natures demand it. Sea pounds at stone, wearing it down, while fire boils water, dissolving it in air.

The alchemical war is as old as the world, as old as the elements themselves.'

THE BOOK OF TOWERS, EXEGESIS 15:7.

T.

here's only one way to catch the Homunculus,' Habryn Kail said, unfolding a map on the dirt and pinning it flat with rocks at each corner. *Following it won't work. Get much closer than we already have, and we'll be caught in the same trap that killed our buses. We have to get in front of it - and we have to do it right, this time. No splitting up; no hedging our bets. We have to be completely committed to the attempt or we might as well give up and go home.'

Sal watched the reactions of the wardens to this bald declaration. The ring of dirty faces, lit from below by the glowing mirrors, watched the tall tracker in exhausted silence. The emptiness of the Broken Lands was a fitting accompaniment to the grimness of Kail's opinion.

*I haven't the strength to argue with you,' said Warden Marmion. His eyes were sunken. What hair remained on his head hung limp and greasy. *What do you suggest we do?'

*We prepare a trap. Something that doesn't rely on the Change to spring or stay shut. Something it won't antic.i.p.ate.'

*Do you have anything in mind?'

*I have an idea. It depends on where we set the trap, though.'

*You have some thoughts in that regard, too, I presume.'

*I do.' Kail took a stub of pencil lead and drew a line on the map from the Haunted City across the Strand. *This is the path the thing is following. We know it hasn't deviated more than a few degrees throughout its journey. I feel confident in a.s.suming that it won't change its habits in the near future. I propose, therefore, that we can make a guess at its ultimate destination. There or nearby I hope to take it by surprise.'

Sal leaned over the map, the better to see what the tracker was driving at. The bold straight line of the Homunculus's path sliced across empty landscape until it crossed the old road they themselves had followed from Moombin. They had been far enough behind it to avoid the effect of its wake, otherwise they might have suffered the same fate as Banner and the others. Their paths crossed again when he, Shilly and Tom had turned north on the approach to the Broken Lands, and they would have crossed again had not Banner waved them down.

Projected ahead, the line exited the Broken Lands and continued over vacant countryside until it hit the Divide. The Divide zigged and zagged from west to east like a lightning bolt through earth, unmistakable for anything natural. The Homunculus's path struck the great rent just west of a sharp one hundred and thirty degree bend. Marked on the map, on the northern flank of the bend, was a small dot. There was nothing else for hundreds of kilometres in any direction.

*What's that?' asked Shilly, leaning on Sal to point at the dot.

*According to the map,' said Kail, *it's a city called Laure.'

*Never heard of it.'

*I have, but I've not been there. It has an ill reputation.'

*For what?'

*Isolationism. And other things.'

*And you think that's where it's headed?' asked Marmion before Sal could press for more information.

*Its path is too direct to be a coincidence.' Kail looked down at him. *Whether it's going there of its own accord or following some obscure directive from Highson, that doesn't concern us. As long as we know where it's going, we can make an effort to head it off on this side of the Divide.'

Sal felt eyes turn to him, perhaps waiting for him to elaborate on his father's motives. He was unable to. Highson and he had exchanged not a single word for five years. His father's state of mind was as unknown to him now as it had always been.

*That sounds like a plan,' he said.

*A plan that hinges on our ability to travel,' said Marmion, turning to Banner.

*The damage is fixed, for the most part,' the Engineer said, her face smudged with grease. *We're recharging the reservoirs from Tom's buggy. That shouldn't take long - an hour or so at the most. We'll have enough to get to Laure.'

Tom agreed with a nod.

*Good.' Marmion stood for a moment with his hand on his chin, considering the map. *I don't really see that we have much choice but to try. Get us ready to roll as soon as the buses are charged. Habryn and I will work out the details of the trap as we go.'

*Can we call ahead?' asked Shilly, leaning on her cane to Marmion's right. *There might be someone in Laure who can help us.'

*Wrong side of the Divide,' said the Warden, dismissing the suggestion without giving it even a second thought. *We're on our own out here.'

Sal opened his mouth to protest.

*Yes?' said Marmion, noticing the movement.

A moment's reconsideration convinced Sal that there was no point arguing. From Marmion's point of view, they were on their own. The ideological divide between the Strand and the Interior was as deep and wide as the actual Divide. Wars had been fought over it - and people like Lodo and Sal had been exiled or worse for defying it. It was simpler sometimes to go with the flow, even if that meant ignoring a potential source of aid.

*Would you like us to be part of this?' he asked instead.

*I a.s.sume you will be, whether I want you to or not.' Marmion's expression was unreadable. *Don't worry. I'll call on you when you're needed.'

*Gee,' said Shilly, *it's nice to be appreciated.'