Dura’s belly lurched as the car jerked into motion. “Toba. Where is this City of yours?”

“At the South Pole,” he said. “Downflux. As far downflux as it’s possible to go.”

Downflux…

Dura closed her eyes.

Dura emerged reluctantly from sleep.

She could feel the laxness of her muscles, the slow rhythm of her heart, the rich, warm Air of the car pulsing through her lungs and capillaries. She opened her eyecups slowly and glanced around the cramped, boxy interior of the car.

The only light came from four small, clear sections of wall — windows, Mixxax had called them — and the little wooden room was immersed in semi-darkness. It was a bizarre situation: to take a shit, she’d had to open a panel and squat over a tube; when she pulled a little lever the waste had been sucked away into the Air. The cabin itself was constructed of panels of wood fixed to a framework of struts and spars. The frame surrounded her, she thought fancifully, like the rib cage of some immense, protective creature. Still half-asleep, she remembered absently her feelings of threat when first climbing into the car. Now, after less than a day, she felt only a womb-like security; it was astonishing how quickly humans could adjust.

Adda’s stretcher was still secured to the struts to which they had strapped it. Adda himself seemed to be asleep — or rather, unconscious. He breathed noisily, his mouth gaping and dribbling fluid; his eyes were half-open, but even his good eye was a small lake of pus which leaked slowly onto his cheek and forehead; small, harmless symbiotes covered his cheeks, lapping at the pus. Farr was curled, asleep, into a tight ball, wadded into one corner of the boxy cabin; his face was tucked into his knees and his hair waved gently as he breathed.

Mixxax sat in his comfortable-looking seat before his array of levers and gadgets. He had his back to her, his eyes focused on the journey ahead of them. As he sat in his undershorts she could see afresh how thin and bony this man from the City really was, how pale his flesh. But, at this moment, in control of his vehicle, he radiated calm and competence. It was that very calmness, the feeling of being in a controlled, secure environment — coupled with the exhaustion of the abortive hunt, the stress of Adda’s injuries, the thinness of the forest Air — that had lulled Dura and Farr to fall asleep almost instantly, once the car had begun its journey.

Well, Dura was grateful for this brief interlude of peace. Soon enough the pressures of the outside world would return — the responsibilities of Adda’s illness, Farr’s vulnerability and need for protection, the unimaginable strangeness of the place to which they were being taken. Before long she would be looking back on this brief, secure interlude in the confining walls of the car with nostalgic affection.

Unwinding slowly, stretching to get the stiffness out of her muscles, she pushed out of her corner and glided across the small cabin to Mixxax’s seat. She anchored herself by holding on to the back of the chair and peered past him out of his window.

Toba Mixxax gave a start, flinching away from her. Dura had to suppress a laugh at the moment of near-panic on his broad face.

“I’m sorry,” he said quietly. “I thought you were asleep.”

“The others still are, I think. How long was I out?”

He shrugged. “A while.”

She peered out of Mixxax’s window, squinting a little at the golden brightness of the Air. From the front face of the car, leather leaders led to a light wooden framework which constrained the strong young Air-pigs Mixxax called his “team.” The laboring pigs were emitting green clouds of jetfart, so dense they half-obscured the animals themselves; but they were making the car sail along the vortex lines, she saw. Thin leather ropes — reins — were attached to the pierced fins of the pigs and led, through a tight membrane in the front face of the cabin, to Mixxax’s hands; Mixxax held the reins almost casually, as if his control of the pigs and car was unthinking, automatic. Dura fantasized briefly about living in such a place as this magical Parz City, where the ability to direct a car like this came as naturally as Waving.

Her eye followed the tunnel of vortices far ahead of the car to the distinct point where they merged, obscuring infinity. And just beyond that red-white point at infinity she made out the dull glow of the South Pole… and perhaps, she wondered, the glow of Parz City itself.

The Crust sailed over them like an immense ceiling, detail whipping past her with disconcerting speed. The trees through which she had hunted still grew here. They dangled from the diaphanous substance of the Crust and following the Magfield lines like hair-tubes; the cup-shapes of their neutrino leaves sparkled as her view of them shifted. But the trees seemed to be thinning: she discerned patches of Crust separating small, regular-looking stands of trees.

…And the exposed Crust was not bare: rectangular markings coated it, each perhaps a hundred mansheights across. The rectangles were characterized by slight differences of color, varieties of texture. Some contained markings which swept across the patches in the direction of the Magfield like trapped vortex lines, but the patterns in others worked aslant from the Magfield direction — even perpendicular to it. And some bore no markings at all, save for random stipples of deeper color.

She stared into the South. The rectangular enclosures covered the Crust from this point in, she saw, marking it out in a patchwork that receded into the misty infinity beyond the end of the vortex lines. Small forms moved across the enclosures, patiently working: humans, dwarfed by distance and by the scale of the enclosures. Here and there she made out the boxy forms of Air-cars drifting through groups of humans, supervising and inspecting.

She felt humbled, dwarfed. The cap of Crust around the Pole was cultivated — but on an immense scale.

Before this journey she had never seen any artifact larger than the Human Beings’ Net. The car of Toba Mixxax, with its unending complexity, was impressive enough, she supposed — but these markings across the Crust were of another order entirely: artifice on a grand enough scale to challenge the curvature of the Star itself.

And put there by humans, like herself. She fought back awe.

She sought for the words Mixxax had used. “Ceiling-farm,” she recalled at last. “Toba Mixxax, this is your… ceiling-farm.”

He laughed, an edge of bitterness in his voice. “Hardly. These fields are much too lush for the likes of me. No, we passed the borders of my ceiling-farm long ago, while you were sleeping… poor as it is, you probably wouldn’t have been able to distinguish it from the forest. When I picked you up we were about thirty meters from the Pole. We’re within about five meters of Parz now; here the Air is thicker, warmer — the structure of the Star is different, just over the Pole itself — and people can live and work much higher, close to the Crust itself.” He waved a hand, the reins resting casually in his grasp. “We’re getting into the richest arable area. The Crust farms from this point in are owned by much richer folk than me. Or better connected… You wouldn’t think it possible for one man to have as many brothers-in-law as Hork IV. Even worse than his father was. And…”

“What are they doing?”

“Who?”

She pointed to the fields. “The people up there.”

He frowned, apparently surprised by the question. “They’re coolies,” he said. “What I mistook your people for. They’re working the fields.”

“Growing pap for the City,” came a growl from behind them.

Dura turned, startled. Adda was awake; though his pus-filled eyecups were as sightless as before, he held himself a little stiffer in his cocoon of clothes and rope and his mouth was working, bubbles of spittle erupting from its comer.