by Larry Niven
Debby had lived her first nineteen years in free fall. Fourteen years in the tree tide had put muscle on her without shrinking her height. Her children—and Ilsa’s, the children they had borne to Anthon—were no taller than ordinary tree dwellers. But Debby was two and a half meters tall. Her fingers were long and fragile; her toes were sturdier if less agile, and the big toes measured six ce’meters. Her rich brown hair was beginning to show gray, but she still wore it a meter long. For swimming she wore it looped in a braid around her throat.
The water was murky. This was a new skill for Debby, but she was learning.
She struck. The ripple of her thrust expanded outward around the great globule, past playing children and the Scientists working their cloth sheet.
A silver shape wriggled on Debby’s spearpoint. Debby reached above her head, tugged hard at the tether, and gasped as her head broke the surface. The waterbird, suddenly thrust into air, expanded its small wings and thrashed mightily. A blow to the head end quieted it. Debby pushed it into a net bag to join five others.
Her chest still heaved with the need for air. She rested quietly on her back, her hands fluttering from time to time to keep surface tension from pulling her under.
Eastward, a thousand klomters past Citizens’ Tree, the cloud patterns thickened into a flattened whirlpool. The Smoke Ring converged beyond and below the whorl in a stream of white touched with blue-green, narrowing as it dropped toward the dazzling point of Voy.
Things tended to collect in that special part of the Smoke Ring, east of Gold by sixty degrees of arc. The citizens had reason to know that the storm-whorl around Gold was dangerous. They assumed that the Clump was too. They had never taken the tree nearer than this.
They had never visited a jungle.
Human beings certainly lived elsewhere in the Smoke Ring, but Citizens’ Tree had never attempted to contact them.
Citizens’ Tree was placid, safe. Working within the pond was as much excitement as Debby ever got these days. Life in Carther States had been different. The occasional raids from London Tree forced the citizens to be always prepared for war, until in one magnificent raid they had ended London Tree’s power forever.
Debby’s connection with the jungle warriors had ended too. A mixed group of copsiks and warriors had stolen London Tree’s carm. The vehicle was old science, powerful and unfamiliar. They and their prisoners had been lucky to bring the carm to any kind of safety; but Carther States was lost somewhere in the sky beyond Gold.
From westward came a cheerful cry. “Citizens! We need muscle!” Debby saw Lawri the Scientist floating in the sky with one hand on the main tether.
Debby snatched at the net bag (six was a nice day’s catch), kicked herself into the sky, and began reeling her line in. She was first to reach the Scientist. Clave and Minya and Mark the Silver Man were leaving the pond, reeling in lines. Gavving had stayed to gather the children.
Four tethers led to the corners of the sheet-covered net, which was now deep underwater. Lawri stationed them along the main tether as they arrived. “Gather it in,” she directed them. “Make loops. Steady pull.”
Debby wrapped her toes and her fingers around the cable, and did her savage best to contract her body. No loop formed. She knew she wasn’t as strong as a tree dweller, but the others were having trouble too.
Lawri called, “Good! It’s coming straight out.”
That was not obvious to Debby. She strained…and gradually the pond bulged. The sheet and its net backing were rising, carrying tons of water. Debby pulled until her knees and elbows met, then shifted her grip and continued pulling.
The pond stretched, and tore. A baby pond pulled clear, leaving a trail of droplets the size of a man’s head. Water flowed over the edges of the cloth but was not lost, for surface tension held it. The main pond pulsed as surface tension tried to form the sphere again.
“Keep pulling!” Lawri shouted. “Steady…okay. That should do it.”
The citizens relaxed. The bud-pond continued to move east on its own momentum, toward the tree, with the net and sheet now in the middle of a pulsing sphere.
Debby coiled line that was now slack. Glancing toward the trunk, she saw what the curve of the pond had hidden earlier.
Parallel to the trunk and many klomters beyond it floated a slender dark line. A young tree, no more than thirty klomters long, and injured; for the in tuft was missing, chopped away somehow. The view was confusing, for the midtrunk was wreathed in cloud…dark, dirty cloud…smoke!
Debby tugged abruptly at another line. The motion set her drifting toward the Chairman. Clave caught her ankle as she arrived. “Something?”
Debby pointed with her toes. “That tree. It’s on fire!”
“…I believe you’re right. Treefodder! It’ll be coming apart. Two fires to worry about.”
Debby had never seen a tree break in half, but Clave spoke from dreadful experience. They might have to move the tree. It would take time to get the carm ready—
Clave had already thought that far. His voice became a whipcrack roar. “Citizens, it’s getting toward dinnertime, and we’ve got all these waterbirds. Let’s break up the swim.”
His voice dropped. “You go now, Debby. Tell Jeffer we may need the carm. We’ll get the women and children down into the tuft, if we’ve got time. Your eyes are better than mine. Do you see anything leaving the tree? Like clouds of insects?”
There were black specks, big enough to show detail. “Not insects. Something bigger…three, four…birds?”
“Doesn’t matter. Get going.”
It had taken Jeffer the Scientist a fifth of a day to cross three klomters of line.
Free fall brought back memories. When Quinn Tribe was lost in the sky after Dalton-Quinn Tree came apart, his crew would have given eyes and limbs to reach a pond. Fourteen years later, the grandmother of all ponds floated three klomters from Citizens’ Tree; and now their main problem was to get rid of most of it. Jeffer wondered if the children appreciated their wealth.
Perhaps they did. Most of Citizens’ Tree, thirty naked adults and children, had come to swim in that shimmering sphere of water.
There was no foliage on the high trunk. It was thick rough bark, with fissures deep enough to hide a man. Jeffer found and donned his tunic and pants, then anchored his toes in a crevice and thrust to send himself gliding out along the bark, toward the carm.
The lift cable ended two hundred meters short of the carm’s dock. The citizens may have feared that careless use of the carm might spray fire across a rising cage. More likely, they feared the carm itself. They would not lightly come too near that ancient scientific thing.
The carm was old science. It was roughly brick-shaped, four meters by ten by thirty-two, and made of starstuff: metal and glass and plastic, sheathed with darkly luminous stuff that took the energy from sunlight. The bulk of it was tanks for hydrogen and oxygen and water. Nostrils at the aft end—four at each corner, and a larger one in the middle—would spurt blue fire on command.
They had neglected the carm of late, and Jeffer accepted some of the blame. The carm made two “flavors” of fuel out of water and the power in the batteries. The batteries held their full scientific charge—they filled themselves, somehow, as long as sunlight could reach the carm’s glassy surface—but the hydrogen and oxygen tanks were almost empty. It was high time they filled the water tank.
The carm’s bow was moored in a dock of wooden beams. Double doors led into a hut with cradles for passengers, moorings for cargo, and a broad transparent window. The window looked forth on nothing but bark. Ventral to the window was a gray sheet of glass and a row of colored buttons.
Jeffer went forward. A touch of a blue button lit the gray glass panel. Blue governed what moved the carm: the motors, the two flavors of fuel supply, the water tank, fuel flow. Jeffer read the blue script:
H2:
0,518
O2:
0,360
H2O:
0,001
POWER:
8,872
The batteries danced with energy. Why not? The carm wasn’t using power. Nobody in Citizens’ Tree had bothered to fill the water tank in seven years; so power wasn’t needed to split water into hydrogen and oxygen. The water tank was virtually dry.
And he could get something done while he waited for Lawri’s pond. Jeffer touched the blue button (the panel went blank) and the yellow (there appeared a line diagram of the carm’s bow, the hut section). He touched a yellow dot in the image, and turned his fingertip. Then he moved aft.
The residual goop in pondwater stayed in the tank after the pure water was gone. Jeffer’s finger motions had (magically, scientifically) caused a spigot in the aft wall to ooze brown mud. He cupped the globule in his hands. He tossed it at the airlock, and most of it got through. Another globule formed, and he sent it after the first. He wiped his hands on his tunic. The mud flow had stopped.
Next he pulled several loops of hose from cargo hooks. He rotated one end onto the spigot, then tossed the coil through the twin doors. Done! When Lawri’s blob of pond arrived, she would find the carm ready to be fueled.
Jeffer returned to the controls. He had a surprise for his wife.
Two sleeps ago, while the rest of the tribe was roasting waterbirds from the pond, Lawri had held one of the creatures up for his perusal. “Have you ever really looked at these?”
Jeffer had seen waterbirds before…but he’d kept his mouth shut, and looked.
There were no feathers. The modified trilateral symmetry common to Smoke Ring life expressed itself in two wings and a tailfin, all in smooth membrane on collapsible ribs. The wings could be held half collapsed for motion within the denser medium of water. Only one of the three eyes looked like a normal bird’s eye. The others were big and bulbous, with large pupils and thick lids. The bodies were slippery-smooth.
“I’ve eaten them, but…you’re right. I’ve seen everything from mobies to triunes to flashers to drillbits, and they don’t look like this. Earthlife doesn’t either. Do you think it’s so they can move through water?”
“I’ve tried looking them up in the cassettes,” Lawri had said. “I tried bird. I tried water and pond. There’s nothing.”
Jeffer’s next sleep had ended with a dream fading in his mind, leaving a single phrase: “…even the fish can fly.”
He’d had to wait until now to try it.
He tapped yellow (the display vanished), then white (and got a tiny white rectangle at the dorsal-port corner). White read the cassettes; white summoned Voice. “Prikazyvat Voice,” he said.
The voice of the carm was a throaty bass, as deep as Mark the dwarf’s voice. “Ready, Jeffer the Scientist.”
“Prikazyvat Read Fish. Read it aloud.”
The cassette was one that Jeffer had stolen from London Tree, but it was no different from Quinn Tribe’s lost records of Smoke Ring life-forms. As Voice spoke, print scrolled down the display screen: words recorded long ago by one of Discipline’s abandoned crew.
FISH
If the birds within the smoke ring resemble fish—legless, designed to move through air weightlessly, as a fish moves through water—then the fish that live within the ponds resemble birds.
Every fish we have examined breathes air. They are not mammals, but lungfish. The single class of exceptions, gillfish, are discussed elsewhere.
Some can extrude a tube to the pond’s surface. A few can expand the size of their fins via membranes, to make them serve as wings. One form, core fish, inflates itself with air, dives to the center of a pond, and expels a bubble. It can stay submerged for up to a day—several Smoke Ring days—rebreathing its air bubble, making forays to hunt, and then returning.
The whale-sized moby uses its pond as a lair from which it bursts to sweep through passing clouds of insects. Moby is a compromise form, and there are others.
Clearly even the largest ponds can break up or evaporate or be torn apart by storm. Every creature that lives in a pond must be prepared to migrate to another: to behave like a bird. Even gillfish—
“Prikazyvat Stop,” Jeffer said. This memory that had surfaced from his adolescent training under Quinn Tribe’s Scientist was going to put him one up on his wife!
Back to work. He tapped white, then green, then each of the five green rectangles now onscreen. Within the great window that faced the bark, five smaller windows appeared, looking starboard, port, dorsal, ventral, and aft. The ventral view had a blur and a flicker to it. The rest were clear, like the window itself.
The aft view looked along the line that led west to the pond. Citizens were returning to the tree. Behind them a bud of pond was already drifting toward the tree, with the harebrain net showing as a shadow within. Lawri’s crazy idea was working.
They swarmed back along the cable toward the midpoint of Citizens’ Tree. Gavving and Minya and Anthon hung back, counting heads to be sure that all children were accounted for. A girl lost her grip and drifted; she was chortling and trying to swim through the air when Anthon scooped her up.
As children arrived, Clave herded the smaller ones, with some difficulty, into a rectangular frame with a slatted floor: the lift cage. He stopped when twelve children were inside. Leave room for a couple of adults.
The rest clung to the rough bark or floated like balloons on their tethers. There were wrestling matches. Eight-year-old Arth was getting good at using the recoil of his opponent’s line. He was Clave’s youngest, and just beginning the tremendous growth of adolescence.
Debby had arrived first. Clave could see her a hundred meters out along the bark, climbing toward the carm.
The bud-pond continued to move. Lawri wore a proprietary smile. Still, Citizens’ Tree had better have more line next time they tried this. The pond was too close. If the tree had brushed it there would have been a flood.
The lift now held a score of children. Whoever was in the treadmill would have a problem braking that weight. It couldn’t be helped. Clave looked about. Mark and Anthon looked ludicrous together. Mark short and wide, Anthon long and narrow, their heads pointing in opposite directions—He called, “Anthon, Mark. Take the children down and bring back any adult you can find. Be prepared to fight a fire.”
Anthon stared in astonishment. “Fire?”
“Burning tree. It’s around the other side of the trunk now. Go down and get some help. Rather—Where on Earth is Rather?”
Mark pointed outward. “I didn’t know any reason to stop them,” he said defensively. “They won’t fit in the lift this trip—”
Clave cursed silently as he watched Rather and Jill clawing their way out along the bark. There was no tide to hurt them here. If they slipped, someone would go get them. But he could have used their help.
Jeffer couldn’t guess how long it took him to realize that the background had changed. Behind the five camera views superimposed upon it, the window no longer showed bark a few ce’meters distant. It showed a huge face, strong, with massive bones: the brutal face of a dwarf.
Chapter Two
DISCIPLINE
from the Citizens’ Tree cassettes, year 6 SM:
FIRE
Making a cookfire in free fall is an excessively interesting experience if what you really wanted was dinner. It’s taken me eight State years to perfect my technique.
The first lesson is that a flame doesn’t rise in free fall. I learned that with a candle, when I was a cadet dreaming of strange worlds. If there’s no wind (turn off the air feed), the candle flame seems to go out.
But it isn’t out yet. There’s wax vapor, and there’s the air around it, and at the interface is an envelope of plasma where gas and oxygen interact. It can stay hot for minutes. Combustion continues at the interface. Wave the candle and pop! The flame is back.
In the case of a cookfire, the wood continues to char. Wait an hour, then blow on the coals with a bellows. The fire jumps to life and there went your eyebrows.
—Dennis Quinn, Ca
ptain
Discipline had been deteriorating.
Cameras outside the hull showed rainbow-hued scars from matter that had penetrated the electromagnetic ramscoop while Discipline was in flight. They also showed newer micrometeorite pocks. Sharls could ward off anything big enough to see coming, by turning on those magnetic shields for a few seconds, but they ate power in great gulps.
One day he might regret even the little power he used to maintain the gardens and the cats.
Within the hull, time had discolored metal and plastic. The air was dust-free; metal was clean, but not recently polished. Many of the servomechs had worn out. All but a few of the crew cubicles were kept cold and dark and airless. Kitchen machinery was in storage, with power shut down. Some of the bedding had decayed. Water mattresses had been drained and stored.
Sharls kept the control room free of water vapor and almost cold enough to freeze carbon dioxide. He hoped that the computer and its extensions would survive longer in the cold. But the gardens and corridors and even some of the cubicles were kept habitable. Sharls left the lighting on a day-night cycle, for the birds and cats and plants.
The gardens were surviving nicely. It was true that some of the plants had died out completely; but after all, his ecosystem was missing its most important factor. Human crew were supposed to be in that cycle, and they had been gone for half a thousand years.
Scores of cats prowled the ship hunting hundreds of rats and a lesser number of turkeys and pigeons. The turkeys made a formidable enemy. The cats had learned to attack them in pairs.
Sharls trained the cats to respond to his voice. He had released the experimental rats long ago. The birds were already loose; they must have been released during that blank spot in his memory, the mutiny; but by themselves they wouldn’t have fed the cats. They were too agile, for one thing. With all of the animal life in the system now, the gardens had a better chance of surviving.