Struck with terrified admiration, she watched it drive through the air towards her, only courage keeping that heavy body aloft. Surelv there had never been such a feat until now.

Her strength was fading- Even with both hands, she could barely hold on. There was no possibility of defending herself with the sword, so she sheathed it. Rising fumes whipped past her face, making her eyes water. Pulling up the frayed end of the rope, Irisis made a quick knot around her waist, one-handed, in case she lost her grip when the beast attacked. It was staggering through the air, now rising, now falling, but always heading for her.

She looked up. No way to tell who, or what, was lifting her. The lyrinx rose above her, struggling to grip the air. Now it plunged, though by her rather than at her. It did not want to lose the prize.

Irisis tried to sway the rope out of the way. It moved but not far enough. The lyrinx caught her by the arm. She tore free, which must have upset the creature's delicate equilibrium for it veered off, flapping furiously.

Now it attacked from the other side. Strands of luminous saliva hung from its open mouth. It was tiring rapidly. She watched it come. If it was so easily disturbed, a more direct attack might just tip the balance.

It swooped. She doubled up her legs and shot them out at its head, as she'd done when a lyrinx attacked her at the manufactory last winter. The rope went the other way and her powerful kick ended up as no more than a tap on the jaw. Irisis lost her grip, fell and, caught by the knot around her waist, flipped upside down.

The lyrinx's teeth snapped together, it swung its left arm but just failed to snatch the bag from her belt. The rope slipped and she thought she was going to fall head-first all the way down into that fiery crack, but it pulled tight. It held.

Irisis swung back and forth without the strength to heave herself upright. The lyrinx came again, a last desperate effort.

Ropes of clotted saliva oozed down its mighty chest. With a hoarse, despairing cry, it lunged for the bag that now hung by her shoulder.

'Help!' she wailed, staring at the flickering light just a few spans above. An unidentifiable figure swayed there, swinging something around its head like a cannonball in a sling. The object hurtled down, looking for all the world like a human head. I must be hallucinating, Irisis thought, as the object struck the lyrinx on its brow ridge. Red showered into its eyes.

The lyrinx gagged, the wings missed a beat, it slid sideways into the sheer black face, and fell out of sight.

The rope jerked and she was hauled up, still upside down. Her head cracked on the sheer fracture surface as she was dragged over the edge, then Irisis was dropped onto the pitchy floor.

'Myrum . . .' she gasped.

It was not Myrum, but Flangers, on his knees in a small pool of blood. He looked ghastly. A mutilated corpse lay not far away, strangely shortened, though she could barely see it through the tears of relief. Or perhaps it was the fumes. Fyn-Mah was sprawled on the path at the beginning of the broken bridge, unmoving.

'What happened, Flangers?'

"Nother lyrinx.' He sucked in a breath as though it was his last, glancing towards a hollow where the dead creature lay. 'Myrum thought he'd killed it.' Flangers hunched over, supporting himself with both arms, gasping. 'He hadn't. Tore his head off.'

'That was Myrum's head you threw at the lyrinx?'

'First thing I could reach. Poor fellow. A good soldier and a decent man.' Flangers lay on the floor without the strength to lift his head.

'Is Fyn-Mah dead too?'

'Don't know.'

Irisis crawled to the small woman and felt her throat. 'She's alive.' She peered over the edge. 'We'd better move. I wouldn't bet that lyrinx is dead.'

'Leave me,' said Flangers. 'Can't walk.'

'Then crawl - I'm not leaving you behind. That was a mighty heave, Flangers. Any idea how we get out of here?'

One finger pointed to the right.

She discerned a series of ledges between the pitch spears, which might have been close enough together to form a track, though it would be a dangerous one.

'I'll carry Fyn-Mah. Bring the bag and the rope.' Unknotting the phynadr bag, she handed it to him.

'Don't think I can.'

'Just try,' she said. 'I can't get it back without you.'

Once more the appeal to duty lifted Flangers beyond what any normal man could have achieved. What a hero he was. And what a waste that such courage should be directed to so bloody an end.

It buoyed her up as well, and Irisis found the strength to lift Fyn-Mah onto her shoulders. She set off, trying not to think about the path ahead. It was killing work. Several times she had to hoist the perquisitor onto a higher ledge, hoping she would not fall off while Irisis clambered up herself. After a desperate twenty minutes they reached the other side. The black mouth of the tunnel was just above them. She pulled herself up into it and smelled fresh air.

'It's not far now, Flangers.'

They lurched along like two bloody wrecks, turned a corner and emerged halfway up a deep but narrow mine pit. The sky was just growing light, though not enough to illuminate the pit. 'At last,' said Irisis, limping on bloody, pitch-stained feet. She turned the other way. 'Where's the air-floater?'

"This isn't the pit we came down,' said Flangers, who, astonishingly, appeared to have rallied a little. 'We're in the wrong place.'

Irisis put Fyn-Mah down on the ledge. 'Then we'll have to climb.'

Flangers was staring at the rim. 'I can see something moving up there.'

They stepped back into the tunnel entrance. Fyn-Mah said, more clearly than before, 'Go round base of pit .., through tunnel . . , other side.'

'You're conscious!' Irisis wished she did not have to pick her up again.

The perquisitor did not answer. Hefting her, Irisis followed the path to the bottom of the pit, around the base and in through a tunnel that had not been visible in the black wall. They were underground for only a few minutes before emerging in a larger pit. The air-floater was waiting across the far side, right where they had left it, its four guards with their crossbows ready. Irisis pushed Fyn-Mah through the ropes, fell through herself and lay on the deck without the strength to rise. Two of the guards carried Flangers aboard.

Muss was already there, gazing up at the rim. He had assumed his old persona - the slim, middle-aged man she'd first met in Gosport - though he still looked frustrated and unhappy. So he didn't get what he went in for, Irisis thought. I wonder what it could be?

'Where were you when we needed you?' she snapped. 'On other duties,' he said, impassive again.

'Where are our mates?' cried a young soldier.

'Dead!' Fyn-Mah tried to sit up but sagged back against the wall of the cabin. 'Go up,' she whispered to Pilot Inouye. 'Out of crossbow range.'

The grapnels were pulled aboard. Inouye twisted a knob on the floater-gas generator and gas whistled up the pipe. The air-floater shot up out of the pit, rising above the hummocks and tar bogs of Snizort, and just in time. A detachment of some hundred soldiers had come through the broken eastern wall and were advancing towards the pit. They stopped and someone waved. Pilot Inouye turned to Fyn Mah. 'They're signalling. I think they want us to land.'

'Keep going!' said Fyn-Mah, forcing herself to her feet. She hung onto the rope mesh, swaying dangerously. 'I have other orders. Guards,' she said to the four men, 'ready your weapons. We cannot be taken.'

The soldiers looked uneasy, but complied. Irisis felt the hairs rise on the back of her neck. She took a crossbow for herself. The loyalty of these men had already been tested. Surely it would take little for them to mutiny - if Fyn-Mah was taken, they would be condemned with her.

On the ground, there was a flurry or activity at the front of the detachment. A black-robed figure waved its arms, a perquisitor Irisis did not recognise. A soldier put a speaking trumpet to his mouth.

'Land at once, whoever you are,' he boomed.

'Go higher!' hissed Fyn-Mah. Clinging death-like to the ropes, she shouted down. 'I may not. I'm on a special mission for Scrutator Xervish Flydd.'

The robed figure snatched the speaking trumpet. 'There is no Scrutator Flydd, only the condemned criminal, Slave Flydd.'

Fyn-Mah let out a muffled cry. She turned to Irisis and Flangers. 'What do I do now?'

'Follow your orders,' said Flangers unhelpfully.

'Muss?' she called.

Eiryn Muss was squatting on the deck, deeply immersed in his own thoughts, and did not answer. Whatever was bothering him, it was more important than their imminent demise.

'Land immediately, in the name of Acting Scrutator Jal-Nish Hlar!' shouted the figure on the ground.

'Perquisitor Fyn-Mah,' said Inouye, 'I must go down. I have a direct order from your superior.'

Fyn-Mah covered her face with her hands.

If the scrutator had fallen, what hope was there for any of them? 'You're risking everything on Flydd,' Irisis said. 'Do you think he can possibly rise again?'

Fyn-Mah groaned, then mastered herself. 'Scrutator Flydd ordered me to go on, no matter what happened to him, and so, I must. No matter what the consequences.'

Irisis felt Death look up from his work on the battlefield, rub a testing thumb down the blade of his scythe, and smile grimly.

The scrutators will torment us all,' cried Inouye, desperately defiant.

'I'm taking the air-floater,' Fyn-Mah gritted. 'If you won't cooperate, we'll throw you down to join your friends and Crafter Irisis will take over your controller.'

Irisis doubted that she could operate it, or that Fyn-Mah would be so ruthless, but the pilot did not know that.

Inouye licked her wind-chapped lips. The bond with the machine was intense, and pilots, like clanker operators, had been known to go insane after their craft was destroyed.

'They'll slay my man and my little children,' she said in a barely audible voice.

'Not if you're forced to it.' said Fyn-Mah in more gentle tones. 'Flangers, make a show.'

Flangers liked it no more than the pilot did, but he took Irisis's crossbow and pointed it at Inouye, in full view of those on the ground.

'This will ruin us all,' wept little Inouye. She obeyed and the air-floater lifted.

'Go north, with all speed,' said Fyn-Mah.

The soldiers on the ground fired their crossbows but the air-floater was out of range and the bolts fell harmlessly back. Someone ran to the broken wall, climbed it and began to signal frantically towards the command area.

'I feared this was going to happen,' said Fyn-Mah. 'With the scrutator lost, there's only one option left.' She groaned and slumped to the canvas deck.

Behind them, three black air-floaters rose from the mound next to the army command area, and followed.

'Or maybe none,' said Irisis, picking the perquisitor up and carrying her inside.

Part Two: Tears.

Eleven.

Gilhaelith was slipping ever deeper into the bottomless pit of tar and there was nothing he could do about it. He'd tried everything, but his geomancy was useless without some kind of a crystal to serve as a focus, and he had none. He'd even attempted to use one of his ever-troubling gallstones, but under the strain it had burst into jagged fragments that were causing him agony. Before they passed, should he live that long, he'd be wishing he were dead.

His only other resort had been mathemancy, that strange branch of the Secret Art Gilhaelith had developed long ago. It proved singularly useless. Mathemancy was a philosopher's Art, ill-suited to any kind of direct action, much less such immediate peril.

Gyrull, Matriarch of Snizort, had abducted him to scry out the remnants of a village lost in the Great Seep seven thousand years ago. Afterwards, she'd kept Gilhaelith beside her, refusing him the use of his globe and the other geomantic instruments he'd brought with him as his means of escape. But the tunnel into the Great Seep had failed, its shell of frozen tar had cracked and hot tar had been forced in. The lyrinx had fled with their relics, just in time. Gilhaelith had tried to follow but he'd not been quick enough.

He took the numbers again, raising a series of random integers to their fourth powers to see what pattern they offered. It was awesomely bad. He tried again, with an even worse result.

The tar now reached to his hips, its suction far too great for him to pull himself out. Ribbons of liquid tar, from a breach in the roof, began to fold onto his head and shoulders, its bituminous reek burning his nose, throat and lungs.

And it was hot. Not burning hot, not enough to blister, but uncomfortable and getting worse. Eventually, if he survived long enough, he would simmer like a crab in a pot. Fortunately, he wouldn't survive. In a few minutes, when that great oozing clot came down on his head, he would suffocate.

A possibility slid into Gilhaelith's mind as if it had been whispered in his ear - to couple his two very different Arts. Geomancy was hopeless because he lacked a crystal to draw power and focus it. Mathemancy was not a tool for directing power at all. But what if. . . ?

If he could create a phantom mathemantical crystal, and use it to draw power and focus it, might that be the solution? It was a last resort - such a crystal must pull power directly into his head. A little too much would cook him from the inside, a gruesome, slow death. A lot too much and he would suffer the agonising fate of anthracism, human internal combustion, though that would not take long to kill him.

The very idea of such a crystal felt alien, and it reminded him of those links the amplimet had drawn throughout Snizort, including one to him. Could it be directing him for some purpose of its own? Too bad - without a crystal he was going to die.

He slipped further into the tar, which was now creeping up his groin. It felt hotter than before. Fortunately he'd worked out the mathemancy of crystals long ago, though to create one with numbers, purely in his mind, was another thing entirely. Still, he had always relished challenges.

Gilhaelith began to construct a crystal in layers, beginning at its base and building towards the apex. It was painfully slow - literally painful, he thought wryly. By the time tar had risen to his waist, the phantom crystal was only half done. His shoulders were covered with ribbony black epaulettes; it was dripping down his forehead, clotting over his eyes, and rubbing just smeared it everywhere.

As Gilhaelith built another layer, the tar seemed to dissolve beneath his feet and he slid down to his chest. A bucket-sized clot landed on his head, pushing him face-first into liquid tar, which was forced up his nostrils. Though he clawed it away, he could not clear his nose enough to breathe.

Turning his head sideways, he managed to get a breath through his mouth. Hum'! The layers went more quickly as he approached the tapering apex of the crystal. Only one layer to go. As he sucked another breath, the rest of the clot fell, burying him completely. And it was so hot. His feet were cooking.

But the crystal was done. Gilhaelith looked for power but found none - the field, which had been waxing and waning for days, was dying. The tunnel had failed because the phy-nadrs had not been able to maintain sufficient power to keep it frozen.

Yet for what he planned, only a little power was required. Gilhaelith sought in another direction and discovered a drifting loop of field, cut off from the rest. He drew power into the phantom crystal but there was not enough to energise it.

He had barely enough breath to try again. He found another loop, this one strong as the field waxed dangerously. The node was desperately overloaded and something had to give. But if it just lasted another minute . ..

His lungs were shuddering for air; fire burned behind his temple as the crystal powered up at last. Gilhaelith used a geo-mantic spell to drive heat from the tar surrounding him, into the seep itself.

He kept at it until the heat licked from his skull to his stomach, the first sign of anthracism. He had to let go. Would it be enough? As the spell faded, a most bitter cold enveloped him, as though he'd been frozen into a block of ice. Then, as the heat of the seep attacked that rigid, frigid shell of tar, it shattered into a thousand pieces.

The shards broke away from his body, leaving him in a cavity lined with fractured tar. The suction was gone; it was solid underfoot. The mosaic fell from his eyes and he could see. Gilhaelith took hold of the still-hard shell of the tunnel and, with a wriggle and a shake, pulled himself onto the floor.

He hurt all over and, behind his eyes, needles pushed relentlessly into the bone. He'd tried too hard and damaged something. He began to crawl blindly down the tunnel. That was where Matriarch Gyrull, who had come pounding back for him, found Gilhaelith. Tossing him over her shoulder, she clawed the last chilly remnants of tar from his nostrils and raced off.

The next few hours were a blur of belching fumes, pounding feet and panicky lyrinx. Gilhaelith saw nothing, for the pain was so all-enveloping he could not open his eyelids. And he was so cold - he could feel the shape of his stomach in ice.

He was carried through a myriad of tunnels, with Gyrull cursing and turning this way and that, and her growing escort hard put to restrain their terror. There was fire underground and they couldn't find a way out, though that wasn't their greatest fear. Gilhaelith had learned enough of their language to deduce that many of the escapeways had been cut off and they expected the unstable node to explode at any time.