Rauc half-laughed. “Look at that. Dura, look… How strange.”

Vaguely irritated at this irruption into her daydream, Dura dropped down from the inverted field. Emerging into the clear Air, she rubbed her hands free of dust. “What is it?”

Rauc hovered in the Air, Waving gently; she pointed downward. “Look at the vortex lines. Have you ever seen them behave like that before?”

Vortex lines, acting strangely?

Dura snapped her head downward and raked her gaze across the sky.

The vortex lines were shimmering — infested with so many small instabilities that it was difficult to see the lines themselves. At the limit of vision Dura could just make out individual ripples racing along the lines, like small, scurrying animals. And the lines were exploding upward, out of the Mantle and toward the Crust. Toward the farm. Toward her.

All of the lines were moving, as deep into the sky as she could see; the parallel ranks of them hurtled evenly out toward her.

There was something else, too: a dark shape far away, at the edge of her peripheral vision; it scored the yellow horizon with a pencil of blue-white light.

“Rauc,” she said. “We have to move.”

Rauc looked up at her, the thin, tired face beneath its veiled hat registering unconcern. “Why? What’s wrong?”

Dura brushed the hat from her head, impatiently shrugging off the straps of her Air-tank. “Give me your hand.”

“But why…”

“It’s a Glitch. And if we don’t move now we’ll be killed. Give me your hand. Now!”

Rauc’s mouth opened wide. Dura saw shock in her expression, but no fear yet. Well, there would be time enough for that. She grabbed Rauc’s hand; the laborer’s palm was toughened by her work but the hand was cool, free of the heat of terror. She kicked at the Magfield with both legs, Waving downward, away from the Crust and toward the approaching flux lines. At first Rauc was dead inertia behind her; but after a few strokes Rauc, too, began to Wave.

When the Star suffered a Glitch the Mantle could not sustain its even, gently slowing pattern of rotation. The superfluid Air tried to expel the excess rotation from its bulk by pushing the arrays of vortex lines — lines of quantized vorticity — out toward the Crust. And the lines themselves suffered instabilities, and could break down…

The women dropped into the racing forest of vortex lines. The lines were usually about ten mansheights apart, so — in normal times — they were easy to avoid. But now, at the birth of this spin storm, they were already rising faster than a Human Being could Wave. The vortex lines fizzed past the women, sparkling electric blue. Instabilities the size of a fist raced along them, colliding, merging, collapsing.

Rauc whimpered. Unwelcome images of the last Glitch, of Esk imploding around the rogue vortex line, crowded Dura’s head. She concentrated on the buffeting of the Air against her bare skin, the thin, unnatural taste of it on her lips, the deadly sparkle of the vortex lines. Now was all that mattered — now, and surviving into the future through this moment.

The vortex lines were growing denser as they crowded toward the Crust, seeking an impossible escape from the Star. It was becoming harder to dodge the lines as they swept past her like infinite blades; she was forced to twist backward and forward, slithering between lines. The instabilities were becoming more prominent, too; now ripples almost a mansheight high were marching along the soaring lines, deepening and quickening as they passed. There was a terrible beauty in the way the complex waveforms sucked energy from the vortex lines and surged forward. The Air was filled with the deafening, deadening heat-roar of the lines.

Soon Dura’s arms and legs, already stiff from a long shift, were aching, and the Air seemed to scrape through her lungs and capillaries. But now, as they penetrated the rushing vortex forest and moved deeper into the Mantle, the lines were starting to thin out. Dura, gratefully, looked down and saw that they were approaching a volume where the lines — though still cutting the Air with preternatural speed — were spaced at about their normal density. Further in still the Air seemed almost clear of lines, temporarily purged of its vorticity.

Dura released Rauc’s hand and risked a look back.

The vortex lines soared upward into the Crust, slicing through nuclear matter and embedding themselves amid the complex nuclei of the Crust material. As they entered the forest ceiling the lines thrashed with instabilities, sending bits of broken matter flying into the Air. The lines were tearing apart Qos Frenk’s ceiling-farm. The crops she had tended only heartbeats earlier were now uprooted, fat wheat-stems scattered in the Air. Ironically Dura could see Crust-tree saplings, anchored by their deeper roots to the forest ceiling, surviving the spin storm where the mutated grass could not.

Further away the buildings at the heart of Frenk’s farm had been torn loose of their moorings to the Crust ceiling; one of them exploded into a shower of wood splinters. Coolies and supervisors were emerging from the fields and buildings, all over the farm. They looked like a cloud of ungainly insects, dropping from the fields toward the hurtling spin lines. Even through the storm Dura could hear their shouts and cries; she wondered if the voice of Qos Frenk himself were among them. Some people squirmed desperately into the lethal rain of vorticity, as Dura and Rauc had done; but most had left it too late. Unable to squeeze through the barrage of twisting lines they were forced to turn back, to climb up toward the Crust.

But there was no haven there.

Dura saw a woman, her Air-mask still in place over her face, pull herself up into the wheat, as if burrowing into the Crust. When the vortex lines struck, her body folded around the lines, backward, her arms and legs outstretched. The woman’s cries rose, thin and clear, before cutting off sharply.

Dura concentrated on the light-smell of the disturbed Air, its sharp presence in her nostrils and on her palate and lips. She wasn’t out of danger yet herself. She watched an instability emerge from a line close to her. The instability grew like a tumor and scythed through the Air, its motion along the line combining with the line’s upward sweep to take it diagonally past her. As it exceeded a mansheight in depth the complex grace of its waveform became distorted; it seemed to be forming a neck at its base, and secondary instabilities rippled around its circumference like attendants.

The neck began to close. Dura stared, fascinated.

The sparkling vortex line crossed itself. The throat closed, and a ring of vorticity spun clear of the line, perhaps two mansheights in diameter. The line itself, freed of its irksome instability, recoiled from the ring in a smooth surge, and then soared on toward the Crust. The ring turned in the Air, quivering, cutting a diagonal path through the array of vortex lines.

A vortex ring.

Rings were believed to form perhaps once a generation, in extremes of spin weather. Dura had never seen one before, and as far as she knew neither had her father, in a long lifetime in the upflux.

She felt a prickle of deep unease. A vortex ring. Something extraordinary is happening to the Star.

She remembered the odd, distant movement she had seen at the start of the storm, the needles of blue light on the concave horizon. Perhaps that blue light was the cause of all this. Making sure she wasn’t in any immediate danger, she glanced around the sky, seeking out the strange vision…

A scream. Rauc.

Dura spun in the Air, her legs thrashing at the Magfield. Rauc had gone from her side, unnoticed. She felt a surge of anger at herself, her own carelessness, her dreamy fascination with the vortex ring.

The scream had come from the path of the vortex ring, as it rose toward the Crust. There was Rauc, high up in the thinning, rushing forest of vortex lines. She must have seen the damage being wrought at the farm, and had taken it into her head to return. To help. And now she was right in the path of the climbing vortex ring. Rauc’s eyes and her round, gaping mouth were like three splashes of dark paint on her round face. The older woman was hanging in the Air, mesmerized by the ring’s oscillations, making no effort to flee.