Hollerbach emitted a sigh; suddenly he seemed to stagger. Grye took his arm. "Chief Scientist — are you all right?"

Hollerbach fixed rheumy eyes on Rees. "I'm tired, you see… terribly tired. You're right, of course, Rees, but what can any of us do, other than give our best efforts to this goal?"

Rees realized suddenly that he had been unloading his own doubts onto the weakening shoulders of Hollerbach, as if he were still a child and the old man some kind of impregnable adult. "I'm sorry," he said. "I shouldn't burden you—"

Hollerbach waved a shaky hand. "No, no; you're quite right. In a way it helps clarify my own thinking." His eyes twinkled with a faint amusement. "Even your friend Roch helps, in a way. Look at the comparison between us. Roch is young, powerful; I'm too old to stand up — let alone to pass on my frailties to a new generation. Which of us should go on the mission?"

Rees was appalled. "Hollerbach, we need your understanding. You're not suggesting…"

"Rees, I suspect a grave flaw in the way we live our lives here has been our refusal to accept our place in the universe. We inhabit a world which places a premium on physical strength and endurance — as your friend Roch so ably demonstrates — and on agility, reflex and adaptabilty — for example, the Boneys — rather than 'understanding.' We are little more than clumsy animals lost in this bottomless sky. But our inheritance of ageing gadgetry from the Ship, the supply machines and the rest, has let us maintain the illusion that we are masters of this universe, as perhaps we were masters of the world man came from.

"Now, this enforced migration is going to force us to abandon most of our cherished toys — and with them our illusions." He looked vaguely into the distance. "Perhaps, looking far into man's future, our big brains will atrophy, useless; perhaps we will become one with the whales and sky wolves, surviving as best we can among the flying trees—"

Rees snorted. "Hollerbach, you're turning into a maundering bugger in your old age."

Hollerbach raised Ms eyebrows. "Boy, I was cultivating old age while you were still chewing iron ore on the kernel of a star."

"Well, I don't know about the far future, and there's not a damn thing 1 can do about it. All I can do is solve the problems of the present. And frankly, Hollerbach, I don't believe we've a hope of surviving this trip without your guidance.

"Gentlemen, we've a lot to do. I suggest we get on with it."

The plate hung over the Raft. Pallis crept to its edge and peered out over the battered deckscape.

Smoke was spreading across the deck like a mask over a familiar face.

Suddenly the plate jerked through the air, bowling Pallis onto his back. With a growl he reached out and grabbed handfuls of the netting that swathed the fragile craft. "By the Bones, innkeeper, can't you control this bloody thing?"

Jame snorted. "This is a real ship. You're not dangling from one of your wooden toys now, tree-pilot."

"Don't push your luck, mine rat." Pallis thumped a fist into the rough iron of the plate. "It's just that this way of flying is — unnatural."

"Unnatural?" Jame laughed. "Maybe you're right. And maybe you people spent too much time lying around in your leafy bowers, while the miners came along to piss all over you.»

"The war is over, Jame," Pallis said easily. He let his shoulders hang loose, rolled his hands into half fists. "But perhaps there are one or two loose ends to be tied up."

The barman's broad face twisted into a grin of anticipation. "I'd like nothing better, tree swinger. Name the time and place, and choice of weapons."

"Oh, no weapons."

"That will suit me fine—"

"By the Bones, will you two shut up?" Nead, the plate's third occupant, glared over the charts and instruments spread over his lap. "We have work to do, if you recall."

Jame and Pallis exchanged one last stare, then Jame returned his attention to the controls of the craft. Pallis shifted across the little deck until he sat beside Nead. "Sorry," he said gruffly. "How's it going?"

Nead held a battered sextant to his eye, then tried to compare the reading to entries in a handwritten table. "Damn it," he said, clearly frustrated. "I can't tell. I just don't have the expertise, Pallis. Cipse would know. If only—"

"If only he weren't long dead, then everything would be fine," Pallis said. "I know. just do your best, lad. What do you think?"

Again Nead ran his fingers over the tables. "I think it's taking too long. I'm trying to measure the sideways speed of the Raft against the background stars, and I don't think it's moving fast enough."

Pallis frowned. He lay on his belly and once more surveyed the Raft, The mighty old craft lay spread out below him like a tray of fantastic toys. Suspended over the deck and marked by the occasional plume of steam he could see other plate craft, more observers of this huge dislocation. A wall of smoke climbed up from one side of the Rim — the port side, as he looked down — and, additionally, each of the trees in the central tethered forest had its own smoke cloak. The smoke was having the desired effect — he could see how the trees' cables leaned consistently to his right as the flying plants sought to escape the shadow of the smoke — and he imagined he could hear the strain of the cables as the Raft was hauled aside. Cable shadows were beginning to lengthen over the deck; the Raft was indeed moving out from under the star which hung poised over it. It was an inspiring sight, one which Pallis in his long life had seen only twice previously; and for such cooperation to be achieved after the turmoil of revolution and war — and at a time when so many of the Raft's best were occupied with the Bridge project — was, he decided, something to be admired.

In fact, perhaps the need to move the Raft had provided the glue which had held society together this far. Here was a project which would clearly benefit all.

Yes, it was all admirable — but if it was too slow it wouldn't mean a damn thing. The falling star was still miles overhead, arid there was no immediate danger of impact, but if pressure was maintained on the trees for too long the great plants would tire. Not only would they prove unable to drag the Raft anywhere — it was even conceivable that some might fail altogether, threatening the Raft's security in the air.

Damn it. He hung his head over the lip of the plate, trying to judge where the problem lay. The Rim wall of smoke looked solid enough; the distant stars cast a long shadow over the masked workers who labored at the base of the cliff of smoke.

Then the problem must be with the tethered trees themselves. There was a pilot, plus assistants, in each tree, and each of them was trying to maintain his own fence of smoke. Those small barriers were probably the most significant factor in influencing the movement of the individual trees. And, even from up here, Pallis could see how ragged and insubstantial some of those barriers were.

He thumped his fist into the deck of the craft. Damn it; the purges of the revolution, and the fevers and starvation that had followed, had left his corps of pilots as depleted of skilled people as most other sectors of Raft society. He remembered Raft translations of the past: the endless calculations, the shift-long briefings, the motion of the trees like components of a fine machine…

There had been time for none of that. Some of the newer pilots barely had the skill to keep from falling out of their trees. And building a lateral wall was one of the most difficult of a pilot's arts; it was like sculpting with smoke…

He spotted a group of trees whose barriers were particularly ragged. He pointed them out to Jame.

The barman grinned and yanked at his control cables.

Pallis tried to ignore the gale in his face, the stink of steam; he put aside his nostalgia for the stately grandeur of the trees. Beside him he heard Nead curse as his papers were blown like leaves. The plate swooped among the trees like some huge, unlikely skitter; Pallis couldn't help but flinch as branches shot past, mere feet from his face. At last the craft came to rest. From here those smoke barriers looked even more tenuous; Pallis watched, despairing, as raw pilots waved blankets at wisps of smoke.