Then he fell silent, his anger dissipating.

There was still something wrong.

The mass of the provisions taken from the casks wasn’t nearly enough to account for the disruption to the tree’s balance. And as for Gover — well, he’d been proven a thief, a liar and worse in the past; but he was right: he wasn’t nearly stupid enough for this.

Reluctantly he released the boy’s shoulder. Gover rubbed the joint, staring at him resentfully. Pallis scratched his chin. “If you didn’t take the stuff, Gover, then who did? Eh?” By the Bones, they had a stowaway.

He dropped to all fours and pressed his hands and feet against the wood of a branch. He closed his eyes and let the tiny shuddering speak to him. If the unevenness wasn’t at the rim, then where…?

Abruptly he straightened and half-ran about a quarter of the way around the rim, his long toes clutching at the foliage. He paused for a few more seconds, hands once more folded around a branch; then he made his way more slowly towards the center of the tree, stopping halfway to the trunk.

There was a little nest in the foliage. Through the bunched leaves he could see a few scraps of discolored cloth, a twist of unruly black hair, a hand dangling weightless; the hand was that of a boy or young man, he judged, but it was heavily callused and it bore a spatter of tiny wounds.

Pallis straightened to his full height. “Well, here’s our unexpected mass, apprentice. Good shift to you, sir! And would you care for your breakfast now?”

The nest exploded. Skitters whirled away from the tangle of limbs and flew away, as if indignant; and at last a boy half-stood before Pallis, eyes bleary with sleep, mouth a circle of shock.

Gover sidled up beside Pallis. “By the Bones, it’s a mine rat.”

Pallis looked from one boy to the other. The two seemed about the same age, but where Gover was well-fed and ill-muscled, the stowaway had ribs like the anatomical model of a Scientist, and his muscles were like an adult’s; and his hands were the battered product of hours of labor. The lad’s eyes were dark-ringed. Pallis remembered the imploded foundry and wondered what horrors this young miner had already seen. Now the boy filled his chest defiantly, his hands bunching into fists.

Gover sneered, arms folded. “What do we do, pilot? Throw him to the Boneys?”

Pallis turned on him with a snarl. “Have you cleaned out the fire bowls yet? No? Then do it. Now!”

With a last, baleful glare at the stowaway, Gover moved clumsily away across the tree.

The stowaway watched him go with some relief; then turned back to Pallis.

The pilot raised his hands, palms upwards. “Take it easy. I’m not going to hurt you… Tell me your name.”

The boy’s mouth worked but no sound emerged; he licked cracked lips, and managed to say: “Rees.”

“All right. I’m Pallis. I’m the tree-pilot. Do you know what that means?”

“I… yes.”

“By the Bones, you’re dry, aren’t you? No wonder you stole that water. You did, didn’t you? And the food?”

The boy nodded hesitantly. “I’m sorry. I’ll pay you back—”

“When? After you return to the Belt?”

The boy shook his head, a glint in his eye. “No. I’m not going back.”

Pallis frowned. “What about your parents?”

“They’re dead. Both of them.”

Pallis bunched his fists and rested them on his hips. “Listen to me. You’ll have to go back. You’ll be allowed to stay on the Raft until the next supply tree; but then you’ll be shipped back. You’ll have to work your passage, I expect…”

Rees shook his head again, his face a mask of determination.

Pallis studied the young miner, an unwelcome sympathy growing inside him. “Well, I’m stuck with you for now. Come on.”

He led the boy across the tree surface, towards his little stock of rations.

After a dozen yards they disturbed a spray of skitters; the little creatures whirled up into Rees’s face and he stepped back, startled. Pallis laughed. “Don’t worry. Skitters are harmless. They are the seeds from which the trees grow…”

Rees nodded. “I guessed that.”

Pallis arched an eyebrow. “You did?”

“Yes. You can see the shape’s the same; it’s just a difference of scale…”

Pallis arched an eyebrow. Smart lad.

The boy ate, as if he’d never been fed.

After letting the boy sleep for a quarter shift Pallis put him to work. Soon Rees was bent over a fire bowl, scraping ash and soot from the iron with shaped blades of wood. Pallis found that his work was fast and complete, supervised or un-supervised. Gover suffered by comparison… and by the looks he shot at Rees, Pallis suspected Gover knew it.

Rees joined Pallis and collected his shift-end rations. The young miner peered absently around at the empty sky. As the tree climbed up towards the Raft, away from the Core and towards the edge of the Nebula, the air was perceptibly brightening.

“Come on,” Pallis said. “Let me show you something.”

He led the boy towards the trunk of the tree.

Surreptitiously he watched as the boy half-walked across the foliated platform, his feet seeking out the points of good purchase and then lodging in the foliage, so allowing him to “stand” on the tree. The contrast with Gover’s clumsy stumbling was marked. Pallis found himself wondering what kind of woodsman the lad would make.

They reached the trunk. Rees stood before the tall cylinder and ran his fingers over the gnarled wood. Pallis hid a smile. “Put your ear against the wood. Go on.”

Rees did so with a look of puzzlement — which evolved into an almost comic delight.

“That’s the bole turning, inside the trunk. You see, the tree is alive, right to its core.”

Rees’s eyes were wide.

Rees woke from a comfortable sleep in his nest of foliage. Pallis hung over him, silhouetted by a bright sky. “Shift change,” the pilot said briskly. “Hard work ahead for all of us; docking and unloading and—”

“Docking?” Rees shook his head clear of sleep. “Then we’ve arrived?”

Pallis grinned. “Isn’t that obvious?”

He moved aside. Behind him the Raft hung huge in the sky. A single star was poised some tens of miles above the Raft, a turbulent ball of yellow fire a mile wide, and the huge metal structure cast a broadening shadow down through miles of dusty air.

Under Pallis’s direction Rees and Gover stoked the fire bowls and worked their way across the surface of the tree, waving large, light blankets over the billowing smoke. Pallis studied the canopy of smoke with a critical eye; never satisfied, he snapped and growled at the boys. But, steadily and surely, the tree’s rise through the Nebula was molded into a slow curve towards the rim of the Raft.

The Raft grew in the sky until it blocked out half the Nebula. From below it showed as a ragged disc a half-mile wide; metal plates scattered highlights from the stars and light leaked through dozens of apertures in the deck. As the tree sailed up to the rim the Raft foreshortened into a patchwork ellipse; Rees could see the sooty scars of welding around the edges of the nearer plates, and as his eye tracked across the ceilinglike surface the plates crowded into a blur, with the far side of the disc a level horizon.

At last, with a rush of air, the tree rose above the rim and the upper surface of the Raft began to open out before Rees. He found himself drawn to the edge of the tree; he buried his hands in the foliage and stared, open-mouthed, as a torrent of color, noise and movement broke over him.

The Raft was an enormous dish that brimmed with life. Points of light were sprinkled over its surface. The deck was studded with buildings of all shapes and sizes, constructed of wood panels or corrugated metal and jumbled together like toys.

A confusion of smells assaulted Rees’s senses — sharp ozone from giant machines around the rim, wood smoke from a thousand chimneys, the hint of exotic cooking scents from the cabins. And people — more than Rees could count, so many that the Belt population would be easily lost among them — people walked about the Raft in great streams; and knots of running children exploded here and there into bursts of laughter.