"Which means going on," Adda said.

She said with a weary irritation, "You don't need to tell me, Adda."

"You'll have to lead them. They won't go by themselves; folk aren't like that. They're like Air-pigs: all wanting to follow the leader but none wanting to lead."

"They won't follow me. I'm not my father."

Adda shrugged. "They won't follow anyone else." He studied her square face, seeing the doubts and submerged strength in its thin lines. "I don't think you really have a choice."

"No," she sighed, straightening up. "I know." She went to talk to the tribesfolk.

When she returned to the nuclear fire, only Philas, the widow of Esk, came with her. The two women Waved side by side. Dura's face was averted, apparently riven with embarra.s.sment; Philas's expression was empty.

Adda wasn't really surprised at the reaction of the rest. Even when it was against their own d.a.m.n interest, they'd snub Logue's daughter.

He was interested to see Philas with Dura, though. Everyone had known about Dura's relationship with Esk; it was hardly the sort of thing that could be kept quiet in a community reduced to fifty people, counting the kids.

It had been against the rules. Sort of. But it was tolerated, and hardly unique - as long as Dura obeyed a few unspoken conventions. Such as restricting her reaction to Esk's death, keeping herself away from the widowed Philas.

Just another bit of stupidity, Adda thought. The Human Beings had once numbered hundreds - even in the days of Adda's grandfather there had been over a hundred adults - and maybe then conventions about adultery might have made sense. But not now.

He shook his head. Adda had despaired of Human Beings long before Farr was born.

"They want to go back," said Dura, her voice flat. "But I'll go on. Philas will come."

The woman Philas, her face drab and empty, her hair lying limply against her angular skull, looked to Adda as if she had nothing left to lose anyway. Well, he thought, if it helped the two women work out their own relationship, then fine.

Some hunting expedition it was going to be, though.

He lifted his spear.

Dura frowned. "No," she said. "I can't ask you to..."

Adda growled a soft warning to shut her up.

Farr straightened up from the burning pit. "I'll come too," he said brightly, his face turned up to Dura.

Dura placed her hands on his shoulders. "Now, that's ridiculous," she said in a parent's tones. "You know you're too young to..."

Farr responded with bleated protests, but Adda cut across him impatiently. "Let the boy come," he rasped to Dura. "You think he'd be safer with those leaf-gatherers? Or back at the place where the Net used to be?"

Dura's anxious face swiveled from Adda to her brother and back again. At length she sighed, smoothing back her hair. "All right. Let's go."

They gathered their simple equipment. Dura knotted a length of rope around her waist and tucked a short stabbing-knife and cleaning brush into the rope, behind her back; she tied a small bag of food to the rope.

Then, without another word to the others, the four of them - Adda, Dura, Farr and the widow Philas - began the slow, careful climb toward the darkness of the Crust.

3.

THEY MOVED IN SILENCE.

At first Dura found the motion easy. The tree slid beneath her, almost featureless, slowly widening as she climbed up its length. The tree trunk grew along the direction of the Magfield, and so moving along it meant moving in the easiest direction, parallel to the Magfield, with the superfluid Air offering hardly any resistance. It was barely necessary to Wave; Dura found it was enough to push at the smooth, warm bark with her hands.

She looked back. The leafy treetops seemed to be merging into a floor across the world now, and the open Air beyond was being sealed away from her. Her companions were threaded along the trunk behind her, moving easily: the widow Philas apparently indifferent to her surroundings, Farr with his eyecups wide and staring, his mouth wide open and his chest straining at the thin Air, and dear old Adda at the back, his spear clasped before him, his good eye constantly sweeping the complex darkness around them. The three of them - naked, sleek, with their ropes, nets and small bags bound to them - looked like small, timid animals as they moved through the shades of the forest.

They rested. Dura took her cleaning sc.r.a.per from her belt of rope and worked at her arms and legs, dislodging fragments of leaf and bark.

Adda glided up the line to her, her face alert. "How are you?"

Looking at him, Dura thought of her father.

She'd been involved in hunts before, of course - as had most adult Human Beings - but always she'd been able to rely on the tactical awareness, the deep, ingrained knowledge of the Star and all its ways, of Logue and the others.

She'd never led led before. before.

Some of her doubt must have shown in her face. Adda nodded, his wizened face neutral. "You'll do."

She snorted. Keeping her voice low enough that only Adda could hear, she said, "Maybe. But what good is it? Look at us..." She waved a hand at the little party. "A boy. Two women, distracted by grief..."

"And me," Adda said quietly.

"Yes," she acknowledged. "Thanks for staying with me, Adda. But even if by some miracle this collection of novices succeeds we'll return with only two, maybe three Air-pigs. We wouldn't have the capacity to restrain any more." She remembered - in the better days of her childhood - hunting parties of ten or a dozen strong and alert men and women, returning in triumph to the Net with whole herds of wild pigs. "And what good will that do? The Human Beings are going to starve, Adda."

"Maybe. But it may not be as bad as that. We might find a couple of sows, maybe with piglets... enough to reestablish our stock. Who knows? And look, Dura, you can only lead those who wish to be led. Don't flog yourself too hard. Even Logue only led by consent. And remember, Logue never faced times as hard as what's to come now.

"Listen to me. When the people get hungry enough, they'll turn to you. They'll be angry, disillusioned, and they'll blame you because there's no one else to blame. But they'll be yours to lead."

She found herself shuddering. "I've no choice, have I? All my life, since the moment of my birth, has had a kind of logic which has led me to this point. And I've never had a choice about any of it."

Adda smiled, his face a grim mask. "No," he said harshly. "But then, what choices do any of us have?"

The forest seemed empty of Air-pigs.

The little party grew fretful and tired. After another half-day's fruitless searching, Dura allowed them to rest, to sleep.

When they woke, she knew she would have to lead them downflux. Downflux, and higher - deeper into the forest, toward the Crust.

Toward the South - downflux - the Air was richer, the Magfield stronger. The pigs must have fled that way, following the Glitch. But everyone knew downflux was a dangerous direction to travel.

The Human Beings followed her with varying degrees of enthusiasm.

The forest was dense, complex. Six-legged Crust-crabs scuttled from Dura as she approached, abandoning webs slung between the tree trunks. Coc.o.o.ns of leeches and other unidentifiable creatures cl.u.s.tered thick on the trunks, like pale, bloated leaves.

A ray turned its blind face toward her.

Adda hissed a warning. Dura flattened herself against the tree trunk before her, wrapping her arms around it and willing her ragged breath to still. The wood pressing against her belly and thighs was hard and hot.

A breath of Air at her back, a faint shadow.

She shifted her head to the right, feeling the roughness of the bark scratch her cheek. Her eyecups swiveled, following the ray as it glided by, utterly silent. The ray was a translucent sheet at least a mansheight wide. At its closest it was no more than an arm's length from her. She could recognize the basic architecture of all the Mantle's animals: the ray was built around a thin, cylindrical spine, and six tiny, spherical eyes ringed the babyish maw set into the center of its face. But the fins of the ray had been extended into six wide, thin sheets. The wings were s.p.a.ced evenly around the body and they rippled as the ray moved; electron gas sparkled around the leading edges. The flesh was almost transparent, so that it was difficult even to see the wings, and Dura could see shadowy fragments of some meal pa.s.sing along the ray's cylindrical gut.

The ray was the only animal - other than humans - that moved by Waving, rather than by squirting jetfarts like pigs or boar. Moving in silence, without the sweet stink of jetfarts, the ray was an effective predator. And its mouth, though tiny, was ringed by jagged, ripping teeth.

The ray slid over the four humans for several heartbeats, apparently unaware of their presence. Then, still silent, it floated away into the shadows of the forest.

Dura counted to a hundred before pushing herself away from the tree trunk.

The vortex lines were dense here, almost tangled together among the trees. The Star, its rotation continually slowing, gradually expelled the vortex lines from the Mantle... until a fresh Glitch struck, when the lines crumbled into deadly fragments before renewing.

The Air was noticeably thinner. Dura felt her chest strain at the stuff and her heart pumped as it sought to power her muscles; from various points in her body she heard the small pops of pressure equalizing. She knew what was happening, of course. The Air had two main components, a neutron superfluid and an electron gas. The neutrons were thinning out; more pressure here was supplied by the gas of free electrons. When she held up her hand before her face she could see the ghostly sparkle of electrons around her fingers, bright in the gloom and evoking dim highlights from the crowding leaves.

But now her vision seemed to be failing. The Air was growing poor at carrying the high-frequency, high-velocity sound waves which allowed her to see. And, worse, the Air - thin as it was - was losing its superfluidity. It started to feel sticky, viscous; and as she moved she began to feel a breeze, faint but unquestionably present, plucking at her face and hair-tubes, impeding her motion.

She found herself trembling at the thought of this sticky stuff congealing in the fine network of capillaries which powered her muscles - the network which sustained her very being.

Human Beings weren't meant to live up here. Even pigs spent no more time close to the Crust than they had to. She heaved at the sludgelike Air, feeling it curdle within her capillaries, and longed for the open s.p.a.ce of the Mantle beneath the roof-forest, for clean, fresh, thick Air.

In all directions around her the tree trunks filled the world. As it became progressively more difficult to see, the trunks, parallel, curving slightly to follow the Magfield, seemed suddenly artificial, sinister in their regularity, like the threads of some huge Net around her. She found herself gripped by a slow panic. Her chest heaved at the unsatisfying Air, the breath noisy in her throat. It took a strong, conscious effort to keep moving, an exercise of will just to keep her hands working at the tree trunk.

She was concerned for Farr. Even in the gloom she could see how distressed he was: his face was white and seemed to be bulging, his eyes half-closed; he seemed barely aware of where he was, and he moved along the trunk stiffly.

Dura forced herself to look away, to carry on. There was no help she could give him. Not now. The best she could do was to move on, to bring home the results of a successful hunt. And as Adda had said, the boy was probably safer with her than anywhere else...

At least Adda was close to Farr. Dura found herself offering up a simple, childlike message of thanks to the watchful Xeelee for the old man's presence and support.

When the climb ended it was with a suddenness that startled her.

The tree trunk she'd followed had broadened only gradually, at last reaching a width just too great for her to stretch her arms around. Now, suddenly, the clean lines of the trunk exploded into a complex tangle of roots which formed a semicircular platform over her head. Peering up, she could see the roots receding into the dim, translucent interior of the Crust itself; they looked almost like human arms, reaching deep into the gossamer solid in search of neutron-rich nuclei of molybdenum, strontium or krypton.

Looking around, she saw how the root system of the tree merged with those of its neighbors in the forest, so that a carpet of wood formed an impenetrable ceiling over the forest. A few strands of purplish gra.s.s sprouted among the roots. The tree trunks, following the Magfield lines, met the root ceiling at an oblique angle.

Soon the others had joined her. The four Human Beings huddled together, clinging to loose roots for stability. It was so dim now that Dura could barely make out the faces of her companions, the outlines of their thin bodies. Philas's eyes were dull with exhaustion and apathy; Farr, trembling, had his arms wrapped around himself, and his mouth was wide as he strained at the residual Air. Adda was as uncomplaining as ever, but his face was set and pale, and Dura could see how his old shoulders were hunched over his thin, heaving chest. Adda took leaves from the bulging pack at his waist. Dura bit into the food gratefully. Insubstantial and unsatisfying as it was, the food seemed to boost what was left of her strength. Farr continued to shiver; Dura put an arm around him and drew him closer to her, hoping to transmit enough of her body warmth to stop the trembling.

Farr asked, "Are we at the Crust?"

"No," Adda growled. "The true Crust is still millions of mansheights above us. But we've reached the roots; this is as far as we can go."

Philas's voice was low and harsh in the thin Air. "We can't stay here for long."

"We won't need to," Dura said. "But maybe we should open up a trunk and start some nuclear burning again, before we congeal here. Adda, could you..."

The old man raised a hand, curtly. "No time," he breathed. "Just listen... all of you."

Dura frowned but said nothing. The four fell into a silence broken only by the rattle of their uneven breaths. Dura felt small, vulnerable, isolated, dwarfed by the immensities of the root systems over their heads. Every instinct ordered her to bolt, to slide back down the tree and plummet through the wall of treetops to the open Air where she belonged; and she could see the same urges in the set faces of the others.

There. A rustle, a distant grunting... It came from the root systems, somewhere to her left. rustle, a distant grunting... It came from the root systems, somewhere to her left.

Adda's face crumpled with frustration. "d.a.m.n it all," he hissed. "I can't hear; my ears are turning to mush."

"I can hear them, Adda," Farr said.

Dura pointed. "That way."

Adda nodded, his good eye half-closed with satisfaction. "I knew it wouldn't take long. How many?"

Dura and Philas looked at each other, each seeking the answer in the other's face. Dura said, "I can't tell, Adda... more than one, I think."

For a few seconds Adda swore steadily, cursing his age, his failing faculties. "Well, into the Ring with it," he said finally. "We'll just have to chance there aren't too many in the herd." In an urgent, harsh whisper he gave them careful instructions on how, in the event of attack by a boar, they should scatter... and work across across the Magfield flux rather than try to flee along it. "Because that's the way the boar will go. And, believe me, the boar will be a d.a.m.n sight quicker than you." His face was a murderous, chilling mask in the twilight. the Magfield flux rather than try to flee along it. "Because that's the way the boar will go. And, believe me, the boar will be a d.a.m.n sight quicker than you." His face was a murderous, chilling mask in the twilight.

Dura said, "Philas, go with Adda and Wave around to the far side of the herd. Take the nets and rope and get downflux from them. Farr, stay with me; we'll wait until the others are in position and then we'll chase the pigs into the nets. All right?"

Hurriedly they pa.s.sed around the equipment they would need. Dura took two short stabbing spears from the bundle carried by Philas. Then Adda and Philas slid silently into the darkness, working across the Magfield by Waving and by clambering across the parallel tree trunks.

Farr stayed close to Dura, still pressed close to her for warmth, trusting. For a few seconds she looked down at him - his eyes seemed vacant, as if he were not fully conscious - and she tried to imagine how she would feel if anything were to befall this boy, as a result of her own ignorance and carelessness.

Well, she thought ruefully, at least she'd done her best for him in the way she'd structured the hunt. It was undoubtedly safer to be upflux of the herd when the hunt started. And she would have been greatly more worried if she hadn't stayed with Farr herself.

With a last, brisk hug, she whispered, "Come on, Farr. We've got work to do. Let's see how close we can get to those pigs without them spotting us."

He nodded dully and drew away from her, still shivering.

Hefting a short spear in each hand, Dura began to pull herself across the lines of the fat trunks in the direction of the noises she'd heard. Moving in this direction, the resistance of the Magfield was added to the thickened viscosity of the Air, and the going was hard. She felt submerged and had to suppress a pang of panic at the feeling of being trapped up here, of being unable to free herself from this solidifying Air.

She did not look back, but was aware of Farr following her, perhaps a mansheight behind; he moved silently save for his rattling breath, and she could hear how he was trying to control the noise of his breathing. The brave little hunter, The brave little hunter, she thought. she thought. Logue would have been proud of him. Logue would have been proud of him.

It took only seconds to reach the pigs; soon Dura could see the blocky forms of several animals sliding between the tree trunks, still apparently oblivious to the humans.

Beckoning Farr to come close to her, Dura lodged herself amid the tree trunks perhaps ten mansheights below the root ceiling.

There were three Air-pigs. The animals, each about the size of a man's torso, worked steadily around the bases of the trees, scooping up purple-green krypton gra.s.s and other small plants. The pigs' fins Waved languidly as they fed, and Dura could see how their eyestalks were fixed on the gra.s.s before them and their mouths were pursed, almost shut. When grazing on the thin foodstuff which floated in the free Air, a pig's mouth could open so wide that it exposed the entire front end of the pig, turning the animal into an open-ended tube, a crude eating machine trailing eyestalks and fins. But here in this failing Air the mouths were barely opening as they worked, lapping and chewing at the krypton gra.s.s. The pigs were keeping their squat bodies sealed up as much as possible, maintaining an inner reservoir of life-sustaining Air; in this way, she knew, the pigs could last for days up here - unlike fragile, weak and ill-adapted Human Beings.

She turned to Farr, who hovered beside her with his eyes barely protruding over the trunk. She mimed: Just three of them. We're in luck. Just three of them. We're in luck.

He nodded and pointed at one of the pigs. Dura, studying the animal more closely, saw that it was bigger than the others: bulkier, clumsier.

A pregnant sow.

She felt a smile spread across her face. Perfect.

She counted one hundred heartbeats, then lifted her spears. Philas and Adda should be in position by now.

She nodded to Farr.