by Larry Niven
“She’s catching up. She’ll have to get past him,” Miya said.
Jack looked down and saw the monstrous shape coming up at him.
Zeera said, “Svetz, try your IR on the beach.”
“Zeera, I want to see—” But he knew the sound of terror. Svetz obeyed: found the beach, looked for hot spots, and zoomed.
Where a Portuguese had burst from the forest forty minutes ago, nine were now wrestling with some massive tube.
“Zeera, get us ready for Fast Forward. I’ll cut these lines.” Svetz dropped to the cargo level and went out the airlock.
Within the shadows of the forest, shelled men were backing their big metal tube against a tree trunk. Svetz had a familiar view, straight down the axis.
He slashed away the never-tested pulley system. Most of it fell into the sea. He pulled what remained through the airlock, then stabbed virtual buttons. The airlock doors closed.
“Get us into FFD,” he told Zeera, but she was already doing it.
The tube blinked fire. Clouds raced. The sun set and rose again.
“I wonder how that came out,” Miya said.
Svetz said, “I’d say Jack is a doomed man. And isn’t it a wonderful thing, to be able to leave all your mistakes behind? I’m just wondering, though, what will happen if those men go home with an obscene statue made of solid gold. They’ll have all of Europe thinking that there’s gold all over these continents, and the locals don’t deserve to keep it.”
There was silence and the flicker of time passing, until Miya asked, “Hanny, did you do anything with the talker?”
Talker? “No. Zeera?”
“Last I saw it, it was lying … lying right next to Thaxir’s head. Do you suppose that was in her pack too?”
“It was broken. Beyond repair, wasn’t it, Zeera?”
“Oh, yes.”
“But that’s still the answer,” Svetz decided. “She took the talker. But why?”
35
During the opposition of 1894 a great light was seen on the illuminated part of the disk, first at the Lick Observatory, then by Parrotin of Nice, and then by other observers. English readers heard of it first in the issue of Nature dated August 2. I am inclined to think that this blaze may have been the casting of the huge gun, in the vast pit sunk into their planet, from which their shots were fired at us.
—The War of the Worlds, by H. G. Wells
The Portuguese ship lasted a minute or two, then zipped away.
They watched the anchor grove shed its black top. A knot remained where it had been, where anchor trees joined the root of the Hangtree; but it had grown a klick or two higher, and the marks of a join were fading. It was all one organism now.
Far above, where Earth’s atmosphere no longer filtered the sunlight of naked space, photosynthesis stored energy as some form of sugar. Water and soil nutrients from below, sugar from above, and so the tree survived and grew.
They watched, and argued, and took turns reading notes into the record. They ate dole bricks and drank recycled water. They took turns sleeping. Svetz and Miya made love on the cargo net while Zeera slept above them, beneath a strobe made by the whirling sun. Years passed outside the Minim’s ruined hull.
More ships came. Wooden buildings sprang up. The green forest shrank back to reveal patchwork farmlands. Farm gave way to factories, then to city.
And the shore receded so gradually that Svetz hardly noticed, but now the Minim stood among six- and eight-story buildings. Was the land rising? Land did rise and fall … but the Hangtree only grew greater. Svetz could picture roots spread through the bedrock beneath this land, lifting.
Passing time began to wear on the Minim’s crew.
Well over a thousand years of development had shaped the Minim’s water-recycling system, but how well had it survived martian shellfire and a crash landing? Fast Forward itself was experimental. After several weeks aboard the Minim, in an environment that changed like dreams, it was easy to imagine that water had begun to taste of trace elements accumulating, that dole bricks had gone bad, that air was developing a stench.
Zeera developed an annoying cough.
Passing centuries swept them into a future that diverged from their own. The tree was grown vast. It cut the sun’s arc like a storm cloud moored in place. Briefly, tall structures with glass faces rose in a crescent about the base of the Hangtree, using the trunk as a main support structure. But the tree was alive and its shape changed year by year. Glass slabs stretched and crumbled … and remained in place as slums. The ruined glass faces and the cracks were mended with stucco or concrete, over and over.
External sensors registered air becoming Post-Industrial.
Zeera’s cough cleared up when she saw that. “They’ll be burning coal in Europe. Running steam engines. Svetz, Miya, that stuff is almost breathable!”
“Read it again,” Miya suggested.
Though factories had appeared even on this equatorial shoreline, readouts still showed too little carbon dioxide, too much oxygen. “We can’t go out anyway,” Miya said. “Futz, we’re all going crazy in here! But we can’t. First thing you know, we’re under arrest for illegal parking.”
“I don’t get this,” Zeera said. “We’re assuming the Hangtree makes sugar, right? Even if chlorophyll isn’t what it’s using. Martians live on the sap! But it’s being made outside the atmosphere, so where’s all this oxygen coming from?”
Miya was willing to speculate. “CO2 and water come up with the sap. Sugar and oxygen go down the same way, or maybe oxygen just diffuses through the bark and drifts down. What the futz—”
Miya’s reactions were faster. She hit the FFD switch.
The sun stopped at high noon, tangled in mirror blossoms.
A metal structure as big as a ten-story building came out of the sea on a tripod of three-hundred-meter legs. It was walking toward the city, but now it turned ponderously, as if it had just seen the Minim. Svetz could almost make out what was inside the tiny dome … and then light brighter than a thousand suns flared at them.
Even a Softfinger plasma blast wouldn’t have hurt the Minim’s superconducting hull. But the gouge over the oxygen tank flared and gave way in the instant before Miya stabbed the FFD switch.
Then everything strobed, but the Minim rang like a bell. Svetz’s seat flung him forward and then back, cracking his neck like a whip. He saw flame backfiring through the break in the oxygen tank. An instant more and the Minim would have exploded like a car in a movie.
Seasons passed outside while the Minim creaked and toppled to a thirty-degree angle, and stuck there.
The three-legged thing was gone.
The city had been leveled. They watched it being rebuilt.
“I think those were Softfingers,” Miya said.
Svetz said, “I didn’t see. Even if it was Martians, were they from Mars or the Hangtree? We’re deep into Industrial times, after all. Mars must be dying. Zeera, how long—?”
“Twelve hundred years to go.”
* * *
Svetz was in the shower bag. The display flashed a radiation warning, and Svetz was about to yell when Zeera switched off the FFD.
He said, “I thought I saw—”
“Here.” Zeera had the meteor sensor going in passive mode. A map of the Earth showed a swarm of red arrowheads. “We just passed the Year Zero, Hanny. First atomic bomb. Propeller planes. Anything that cracks the speed of sound now isn’t local.”
Arrowheads swarmed over the center of the North American continent, but others were on the equator just about … here? Svetz looked up. An overlay on the dome was blinking red arrowheads around little fast-moving dots.
“Those are Softfinger lens ships,” Miya said. “They’re invading Earth again. What do you think, are they looking for nuclear test grounds?”
Ten lens ships all wheeled to converge on the Minim. Svetz said, “I think we should punch out.”
Miya hit the FFD. Plasma cannons blinked and were gone. Citys
cape around the Minim showed craters and broken walls. They began to grow back.
“Futz. I’d have liked to know more about that,” Miya said.
Zeera said, “Mars must be on its last breath by now. In twenty years we’ll put our first probes around Mars, and not a drop of water or a whiff of oxygen left. They must be desperate. Anyway, we’re halfway home.”
* * *
They waited it out.
They detected a much bigger blast of radiation: another lens ship attack, or else they’d seen the One Race War, if time hadn’t been bent too badly.
An earthquake shook the city, blink, and half the buildings were down. That must have been the shock from the Hammer of August falling offshore from Chili in 2391. Shoreline cities had washed away. Bureau of Space Resources had not been able to stop the minor asteroid; they didn’t even have spacecraft to mount a pretense. The United Nations hierarchy took the blame for the destruction, and were executed. Waldemar the First took power.
Building styles changed: they were smaller, more graceful, with more land around them. Population was dwindling, partly due to UN planning, but not everyone could adjust to post-Industrial air. “We’re right on track,” Zeera said, and coughed.
“We don’t know that.”
“Time lines converge when they can. Changes we make are smoothed out. You’ve seen that, Svetz.”
Miya usually sat out these discussions. She didn’t know enough history to have an opinion. They mostly argued to convince Miya.
So Svetz said, “The time machine is too big to move itself. The extension cage goes out on an arm that can swing in four dimensions. Coming home, there’s no telling where it might swing to. I’ve met someone from a culture that blasted the human race to extinction. Wrona came from one where wolves evolved instead of men. But I’ve always come back to the Institute time line. Because the extension arm is attached at both ends! But the Institute time line can change too, Zeera. You’ve seen that.”
“And we put it back.”
Miya was looking up through the dome.
The Hangtree filled the sky. The Moon and stars hung in its branches. The Moon was only one light among a hundred mirror blossoms. Mag specs could find strange architectures forming tiny cityscapes along the trunk.
She whispered, “What legends are being made about that? We don’t have to wonder, do we? Yggdrasil. The axis runs through the Earth. A variety of heavens are in the branches. Hanny, how could we have had the legends before the tree was in place?”
“There were legends of werewolves before I ever found Wrona’s time line,” Svetz said. “Dreams and stories wander across the time lines.”
“Well.” Miya gestured upward. “You think it’s so easy, then put that back the way it was.”
“I thought you wanted it.”
* * *
The black was very restful. Sleep had not favored Svetz for a long time, but now the darkness went on and on. He slept as if drugged.
In the sudden light he snapped awake and—
The sun sat on the ocean and wouldn’t move.
Barricades and familiar UN police uniforms surrounded the Minim. Thousands of people surrounded the barricades. A few wandered inside the perimeter, acting like they knew what was going on.
Miya and Zeera were asleep in their command chairs. Svetz ate a dole brick while he watched and waited. Presently Miya stirred. Svetz asked her, “Did you turn off the Fast Forward?” and then he noticed a dribble of silver where Jack’s coin had run molten.
Miya saw what surrounded them and jerked upright. “It’s present time! Hanny, we need to find a vidphone.”
36
The stem spreads its branches over the entire sky; their leaves are the clouds, their fruits the stars … The ash tree (Fraxinus) itself is the Nordic Tree of Life, symbol of strength and vigor.…
—“The Ash Tree,” from Mattioli’s Commentaires, Lyons, 1579
As a police Roton lifted them toward the sky, they saw a metropolis of eight to ten million spread beneath the vastness of the Hangtree. Root Town, the police pilot called it, and World Tree.
An hour later the Roton set them down at the Institute for Temporal Research in Angels City, west coast of North America Province, where the garden had been.
They took deep gulps of air flavored by cactus blooms. The roses and once-edibles were gone. Scores of varieties of cactus bloomed in dry earth and perfect crescent dunes. Was this some whim of the new Secretary-General?
And where was the ornamental pond? The pond was where they dumped the heat from a returning X-cage!
They were still enjoying the taste of post-Industrial air. Zeera’s cough had come back during that last thousand years, and Svetz had caught it too. They’d been sure the Minim’s air was foul. The instruments were sure it wasn’t.
A crowd wove its way through the cactus to meet them.
Willy Gorky shouldered between them. He had lost weight. “Miya, why didn’t you call? How did you get here?”
“Fast Forward. What else was there?” she snapped. “Willy, why didn’t you send us an X-cage?”
“We’ve only just finished resetting the small X-cage! That was no trivial problem, Miya. You never gave us a date.”
Miya said, “But why would—”
“Got it,” said Svetz. Ra Chen’s disgusted look suggested that he’d seen it too. “How long has it been since our last call? Four hours?” Ra Chen shrugged his eyebrows: Yes. “Miya, we used Fast Forward, and that’s why we didn’t get rescued. Because we’re already here.”
Zeera was nodding. “The other end of the talker link, before the talker was smashed. That was present time. That’s when the FFD burned out. These things won’t go into the future. Four hours ago? If we’d been awake we’d have called you right back!”
“But why can’t we still send—” Gorky stopped, seeing the way they all looked at him. “What would happen if we sent a rescue vehicle now? Would you pop like so many soap bubbles? Would I be looking at two of everyone?”
Nobody answered. Nobody knew.
* * *
The time machine was running on standby. The large and small X-cages looked ready to go, though none of the stations were manned.
A dozen techs were seated around the drinks dispenser, off duty now that the time travelers had been returned. Svetz recognized dark Hillary Weng-Fa, pale Zat Forsman and ruddy Wilt Miller from his own past. The rest were strangers, though they knew him.
While the two Heads and three time travelers walked in and took seats, Zat and a stunning Eurafrican woman, tall and narrow as a soda straw, put coins in the dispenser without asking what anyone wanted, and brought them—water.
Clean water. Svetz savored the taste. People were acting peculiar; he would wait to learn why. And why the drinks dispenser had only two settings. And what was it about the way they all looked?
The time travelers must look like three rats turned loose from a dirty cage. Ra Chen was amused and not hiding it. He looked good: he too had lost weight.
He said, “We jiggered the inertial calendars on the X-cages. The intertemporal talker is a kind of a little X-cage, after all. Whatever travels in time needs more energy to coexist with it. It’s like hitting a bump: we can sense that.”
Willy Gorky exclaimed, “That’s what you were doing?”
Ra Chen laughed. “We never got a date, but there are tricks we can pull. We’re all set to send the X-cages back toward minus 500 AE, which is just pre-Columbian, and pop out where the talker was ruined—when you landed, right, Zeera?—pick you up, leave an instrument package and come home.
“Still, we don’t know everything about time. Zeera, did you learn anything about the squirrel?”
After a long moment Zeera said, “Squirrel?”
Ra Chen frowned. “Batatosk?” Zeera was still looking blank, as well she might. “Secretary-General Victor Four wants the giant squirrel that used to run up and down the World Tree. It was bigger than Whale, so he’s got to have i
t. If it was a squirrel at all. Ole Romer, the ancient Danish astronomer, he saw it and thought it was a squirrel, but what it was…” Ra Chen felt their confusion. “What?”
“Sir, it seems we’ve changed the past a little,” Svetz said. “What was our mission?”
“We know when it died, Svetz. The impact caused the tidal wave that washed away Rio de Janeiro! It might have been sick or old for longer than that. But, futz, the X-cage was already set for pre-Columbian. Batatosk must have been in its prime then. Locate it, send for the large X-cage, get the squirrel and bring it home.”
“Nothing about Martians?”
“Martians?”
“Tree dwellers?”
“Legends. Fire giants, frost giants. If they were real, they’ve been extinct since … oh, before serious telescopes. Those were Martians?”
Willy Gorky looked at Ra Chen before he spoke. “I’d like to rescue some Martians. Did you have any contact with them?”
“Mostly hostile.” Svetz saw body language he half understood. He asked, “Tell me about merging History Bureau and Bureau of the Sky Domains.”
Willy said, briskly and without rancor, “Right, it’s all History now. Victor Four likes strange animals, just like his brother. He’s financed a Heavy Lift Extension Cage.”
“We fulfilled our mission,” Svetz said a bit belligerently. “We went to Mars for the seeds to grow that,” and he gestured southeast. Far around the curve of the world, the Hangtree still owned the sky. “We didn’t just grow seeds, we brought back the tree itself. With that we can own the sky!”
Willy Gorky said, “Not under Victor Four, I think. Mars? What’s it like?”
Svetz swept up their plastic cups and went to the dispenser for refills. He came back cradling five cups, and set them down without spilling. He’d bought himself a few seconds to think.
The dispenser had only two settings: water and carbonated water. That seemed important.
He said, “Willy, we had a Martian too, but she’s gone back up the tree—”
Bong.
Miya demanded, “What the futz was that?” But Svetz and Zeera were running toward the Guide Pit, and the Heads were just behind them.