He shook his head tiredly. He had had enough wonders for one shift. If only Gover would give him a few hints about what was going on—

He closed Ms eyes. Come on, think it through, he told himself. He thought of the Raft as he had seen it from above. Had it looked bowl-shaped? No, it had been flat all the way to the Rim; he was sure of that. Then what?

Fear shot through him. Suppose the Raft was falling! Perhaps the cables on a thousand trees had snapped; perhaps the Raft was tipping over, spilling its human cargo into the pit of air—

He snorted as with a little more thought he saw it. The bus was climbing out of the Raft's gravity well, which was deepest at the structure's center, If the bus's brakes failed now it would roll back along the plane in from the Rim towards the Raft's heart…just as if it were roiling downhill. In reality the Raft was, of course, a flat plate, fixed in space; but its central gravity field made it seem to tilt to anyone standing close to the Rim.

When the slope had risen to one in one the bus shuddered to a halt. A set of steps had been fixed to the deck alongside the bus's path; they led to the very Rim. The passengers jumped down. "You stay there," Gover told Rees; and he set off after the others up the shallow stairs.

Fixed almost at the Rim was the huge, silhouetted form of what must be a supply machine. The passengers formed a small queue before it.

Rees obediently remained in his seat. He longed to examine the device at the Rim. But there would be another shift, time and fresh energy to pursue that.

It would be nice, though, to walk to the edge and peer into the depths of the Nebula… Perhaps he might even glimpse the Belt.

One by one the passengers returned to the bus bearing supply packets, like those which Pallis had brought to the Belt. The last passenger thumped the nose of the bus; the battered old machine lurched into motion and set off down the imaginary slope.

Pallis's cabin was a simple cube partitioned into three rooms: there was an eating area, a living room with seats and hammocks, and a cleaning area with a sink, toilet and shower head. Pallis had changed into a long, heavy robe. The garment's breast bore a stylized representation of a tree in the green braid which Rees had come to recognize as the badge of Pallis's woodsman Class. He told Rees and Gover to clean themselves up. When it was Rees's turn he approached the gleaming spigots with some awe; he barely recognized the clean, sparkling stuff that emerged as water.

Pallis prepared a meal, a rich meat-sim broth. Rees sat cross-legged on the cabin floor and ate eagerly. Gover sat in a chair wrapped in his customary silence.

Pallis's home was free of decoration save for two items in the living area. One was a cage constructed of woven slats of wood, suspended from the ceiling; within it five or six young trees hovered and fizzed, immature branches whirling. They filled the room with motion and the scent of wood. Rees saw how the skitters, one or two adorned with bright flowers, fizzed towards the cabin lights, bumping in soft frustration against the walls of their cage. "I let them out when they're too big," Pallis told Rees. "They're just — company, I suppose. You know, there are some who bind up these babies with wire to stunt their growth, distort their shapes. I can't envisage doing that. No matter how attractive the result."

The other item of decoration was a photograph, a portrait of a woman. Such things weren't unknown in the Belt — the ancient, fading images were handed down through families like shabby heirlooms — but this portrait was fresh and vivid. With Pallis's permission Rees picked it up—

— and with a jolt he recognized the smiling face.

He turned to Pallis. "It's Sheen."

Pallis shifted uncomfortably in his chair, his scars flaring red. "I should have guessed you'd know her. We — used to be friends.»

Rees imagined the pilot and his shift supervisor together. The picture was a little incongruous — but not as immediately painful as some such couplings he had envisaged in the past. Pallis and Sheen was a concept he could live with.

He returned the photo to its frame and resumed his meal, chewing thoughtfully.

At the turn of the shift they settled for sleep.

Rees's hammock was yielding and he relaxed, feeling somehow at home. The next shift would bring more changes, surprises and confusions; but he would face that when it came. For the next few hours he was safe, cupped in the bowl of the Raft as if in the palm of a hand.

A respectful knock jolted Hollerbach out of his trance-like concentration. "Eh? Who the hell is that?" His old eyes took a few seconds to focus — and his mind longer to clear of its whirl of food test results. He reached for his spectacles. Of course the ancient artefact didn't really fit his eyes, but the discs of glass did help a little.

A tall, scarred man loomed into semi-focus, advancing hesitantly into the office. "It's me, Scientist. Pallis."

"Oh, pilot. I saw your tree return, I think. Good trip?"

Pallis smiled tiredly. "I'm afraid not, sir. The miners have had a few troubles—"

"Haven't we all?" Hollerbach grumbled. "I just hope we don't poison the poor buggers with our food pods. Now then, Pallis, what can I do for you — oh, by the Bones, I've remembered. You've brought back that damn boy, haven't you?" He peered beyond Pallis; and there, sure enough, was the skinny, insolent figure of Gover. Hollerbach sighed. "Well, you'd better see Grye and return to your usual duties, lad. And your studies. Maybe we'll make a Scientist of you yet, eh? Or," he muttered as Gover departed, "more likely I'll lob you over the Rim myself. Is that all, Pallis?"

The tree-pilot looked embarrassed; he shifted awkwardly and his scar network flared crimson. "Not quite, sir. Rees!"

Now another boy approached the office. This one was dark and lean and dressed in the ragged remnants of a coverall — and he stopped in surprise at the doorway, eyes fixed to the floor.

"Come on, lad," Pallis said, not unkindly. "It's only carpet; it doesn't bite."

The strange boy stepped cautiously over the carpet until he stood before Hollerbach's desk. He raised his eyes — and again his mouth dropped with obvious shock.

"Good God, Pallis," Hollerbach said, running a hand self-consciously over his bald scalp, "what have you brought me here? Hasn't he ever seen a Scientist before?"

Pallis coughed; he seemed to be trying to hide a laugh. "I don't think it's that, sir. With all respect, I doubt if the lad's ever seen anyone so old."

Hollerbach opened his mouth — then closed it again. He inspected the boy more carefully, noting the heavy muscles, the scarred hands and arms. "Where are you from, Sad?"

He spoke up clearly. "The Belt."

"He's a stowaway," Pallis said apologetically. "He travelled back with me and—"

"And he's got to be shipped straight home." Hollerbach sat back and folded his skinny arms. "I'm sorry, Pallis; we're overpopulated as it is."

"I know that, sir, and I'm having the forms processed right now. As soon as a tree is loaded he could be gone.»

"Then why bring him here?"

"Because…" Pallis hesitated. "Hollerbach, he's a bright lad," he finished in a rush. "He can — he gets status reports from the buses—"

Hollerbach shrugged. "So do a good handful of smart kids every shift." He shook his head, amused. "Good grief, Pallis, you don't change, do you? Do you remember how, as a kid, you'd bring me broken skitters? And I'd have to fix up little paper splints for the things. A damn lot of good it did them, of course, but it made you feel better."

Pallis's scars darkened furiously; he avoided Rees's curious gaze.

"And now you bring home this bright young stowaway and — what? — expect me to take him on as my chief apprentice?"