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 grass and other small plants. The pigs’ fins Waved languidly as they fed, and Dura could see how their eyestalks were fixed on the grass 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 grass. 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.

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.

The two humans erupted from behind their trunk. Dura yelled as loudly as the thin Air would permit; she hurled herself along the Magfield flux at the pigs, rattling her spears against the wood of the trunk. Beside her Farr did the same, his hair tangling almost comically.

At their approach the pigs’ mouths snapped shut. Their eyestalks lifted, rigid, to fix straining gazes on their sudden assailants. Then, as if with one mind, the pigs turned and bolted.

The animals hurled themselves along the Magfield lines, seeking the easiest and quickest escape. They clattered against tree trunks and bounced over roots, their jet orifices farting clouds of green-stained, sweet-smelling Air. Dura and Farr gave chase, still roaring enthusiastically. Suddenly Dura found herself bound up by the excitement of the hunt, and a new energy coursed through her.

The pigs, of course, outran Dura and Farr easily. Within a few heartbeats the animals were disappearing into the darkness of distance, trailing clouds of jetfarts…

But there were Adda and Philas, waiting just a little further down the Magfield, with a net pulled tight between them and with stabbing spears at the ready.

The first two pigs were moving too rapidly to stop. They turned in the Air and tumbled against each other, their huge mouths popping open to emit childlike squeals, but they hurtled backside first into the net. Philas and Adda worked together, a little clumsily but effectively. Within a few heartbeats they had thrown the net around the two pigs and were prodding at them, trying to force them to subside. Green jetfarts squirted from the pigs, and the net bulged as the terrified animals strove vainly to escape. By the time Dura got there they would have the animals trussed up and then…

There was a scream behind her. Farr’s scream.

She whirled in the Air, Adda and Philas forgotten. The third pig — the pregnant sow, she saw — had evaded Adda’s net. Terrified and enraged, it had flown down, away from the root ceiling, and was now plummeting up through the trees, back along the Magfield flux… and straight at Farr.

The boy gazed at the animal’s flapping fins and rigid, staring eyestalks, apparently transfixed. He isn’t going to get out of the way, Dura realized. And the momentum of the pig would crush him in a moment.

She tried to call out, to move toward the boy — but she was plunged into a nightmare of slow motion. The Magfield was thick, clinging, the Air a soupy mass in which she was embedded. She struggled to get free, to shout to her brother, but the hurtling, blurring speed of the pig reduced her efforts to the trivial.

There was barely a mansheight between the pig and the boy. Dura, trapped in viscous Air, heard herself scream.

Suddenly the sow opened its mouth wide and bellowed in agony. Jetfarts staining the air, it veered abruptly. One ventral fin caught Farr with a side-swipe which sent him spinning against a tree trunk… but, Dura saw with a flood of relief, he was no more than shocked.

As the sow tumbled in the Air the reason for its distress revealed itself: Adda’s long spear, protruding from the sow’s belly. The spear quivered as the beast thrashed, seeking an escape from this sudden agony.

Now Adda himself raced along the Magfield, ungainly but determined. Behind him the two trapped pigs were struggling free of the abandoned net. Adda bellowed: “She’s gone rogue… Dura, get to the boy and keep him away.”

Now the pig settled in the Air, all six of its eyestalks triangulating on the old man. Adda slowed to a hover, arms and legs outspread, his gaze locked on the pig.

Dura said uncertainly, “Adda, get out of the way… I think…”

“Get the damn boy.”

Dura hurried to obey, skirting the hovering pig.

With a howl that rent the glutinous Air, the pig charged Adda.

Adda twisted in the Air and began to Wave out of the way, his legs thrashing at the Magfield…

But, Dura saw instantly, not fast enough.

Clinging to the weeping Farr there was nothing she could do as the final, ghastly moments unfolded. Adda’s face showed no fear — but no acceptance either, Dura saw; there was only a grimace of irritation, perhaps at this newest failure of his crumbling body.

As it closed on Adda, trailing green clouds of jetfarts, the sow opened its mouth.

The huge, circular maw closed on both Adda’s legs. The momentum of the hurtling sow carried away both pig and Adda, and Dura cried out as she saw Adda’s fragile body smashed against a tree trunk. But he was still conscious, and fighting; with both fists he pounded on the sow’s wide, quivering back.

Dura kicked away from the tree and Waved as hard as she could toward the pig. Philas was approaching the pig from the far side, her stabbing spears held out before her. The woman’s eyes were wide, emptied by shock and terror.

The pig, halted by its impact with the tree, pulled back into clear Air now, and it began, with lateral squirts of gas, to rotate around its long axis. Adda seemed to realize what was happening. With his legs still trapped, he beat harder at the pig’s flank, cursing violently. But still the pig twisted, ever faster, becoming at last a blur of fins and eyestalks. Jetfart gas trailed around its body in circular ribbons, and electron glow sparkled from its fins. Adda, at last, fell backward and lay against the pig’s long flank, his knees bent cruelly.

This was the way boars killed their prey, Dura knew: the boar would spin so fast that the superfluidity of the Air which sustained all animals in the Mantle, including humans, broke down. It was simple, but deadly effective. Even now, she knew, the pain of Adda’s trapped legs, the agony induced by the whirling of the world around him, would be subsumed by a dull, disabling numbness as his muscles ceased to function, his senses dimmed, and at last even his mind failed.

With a yell from deep in her gut, Dura threw herself at the whirling animal. She scrabbled at its smooth, slippery hide, feeling her belly and legs brush against its hot flesh. She stabbed at its tough epidermis once, twice, before being hurled clear. She tumbled backward through the Air, colliding with a trunk hard enough to knock the breath out of her.