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.

Dura swam quickly to his side. "I'm sorry we woke you," she whispered. "How are you feeling?"

His mouth twisted and his throat bubbled, in a ghastly parody of a laugh. "Oh, terrific. What do you think? If you were any better-looking I'd invite you in here to keep me warm."

She snorted. "Don't waste your Air on stupid jokes, you old fool." She tried to adjust the position of his neck, smoothing out rucks in the rolled-up cloth around it.

Each time she touched him he winced.

Toba Mixxax turned. "There's food in that locker," he said, pointing. "We've still a long way to go."

In the place he'd indicated there was a small door cut into the wall, fixed by a short leather thong; opening it, Dura found a series of small bowls, each covered by a tight-fitting leather skin. Peeling away one of the skins she found pads of some pink, fleshy substance, each about the size of her palm. She took a pad and nibbled at it.

It was about as dense as meat, she supposed, but with a much softer texture. And it was delicious — like the leaves of the trees, she thought. But, as far as she could tell from her small sample, a lot denser and more nutritious than any leaf.