Rainbow Mars (18 page)

Sunlight blasted their eyes.

Day and night strobed. Zeera cursed and clenched her eyelids tight. Miya looked out, grim and squinting. Svetz pulled his helmet into place.

Now the sun was a dark spot hurtling east to west, over and over, but the light-dark-light landscape was still uncomfortable. Pressure tents and vehicles appeared in a pattern not quite centered on the spot where the
Minim
moved through time, all built in the fashion of the red humanoids. The Tanker disappeared in sections. A few minutes later all the activity on the plateau went away. The temp housing began to decay and collapse.

Miya switched off on a day in late afternoon.

The Hangtree was high in the sky, east by south. Bouquets of tremendous silver flowers bloomed at both ends. The splintered bottom end had healed: it was pointed like a stem emerging from a silver corsage, ten thousand klicks above Mars.

Miya asked, “How far did we come?”

“There's no gauge for the FFD,” Zeera said. “Just an on-off switch.”

“Futz! Give me a guess, then. Three years or so? The Martains must think we just disappeared. Now the tree's higher, but it took forever to get there. So the Hangtree is leaving Mars, but it's taking its sweet time—”

“Miya, what's your
plan?
” Zeera demanded.

“Launch.”

“We can't reach Earth!”

“Rendezvous with the Hangtree. It's not in geosynchronous orbit anymore, it's higher than that, but we can still reach the midpoint. The midpoint will still be in free fall.”

“We can do all that,” Zeera said carefully, “but why do we want to?”

“Launch us. I'll tell you on the way.”

“Are we in a hurry? Miya, what you need is sleep!”

“I want to get
moving.
Hanny, get into your suit. You too, Zeera. If I'm wrong I want to
know
it.”

“Midpoint of the tree, aye aye,” Zeera said. “Check my work.”

They were pilots, he wasn't. Svetz watched them, and presently said, “The telescopes in the crater may be up again. When they see us in flight, the party's over.”

Miya murmured, “Launches are finicky, Hanny.”

Zeera said, “I've got the
Minim
in low orbit. We circle half around the planet and do a second burn—”

Svetz reclined his chair and watched for double-wok ships in a navy blue sky.

He snapped out of a sound sleep when the floor roared at him and gravity doubled. The ship rolled. The biggest mountain in the solar system dwindled behind them.

The motors went quiet. Zeera said, “We'll make another burn to close with the tree. Twenty-five minutes. Miya, are you planning to moor us to the trunk?”

“Right. I think I've worked out the Hangtree life cycle.” Miya closed her eyes and said, “We don't have fuel to reach Earth, right? But we can get on the Hangtree and ride it. Anchor to the tree. We'll get there with a reserve of fuel. Then Fast Forward until we see where it's going. If I'm wrong, we abort. Reentry and Fast Forward, land at Mars Base One and call Willy. Start over.”

*   *   *

Mars was a vast black curve beneath black sky. Fuzzy light was just peeping over the horizon: not the sun, but the Hangtree's upper cluster of mirrors.

Zeera started her second burn.

Svetz was able to make out a vertical line, almost invisible against the black sky, motionless and infinitely distant. It didn't look threatening.

“What's that?” he asked, and it was suddenly far too close. Zeera yelled and fired attitude jets. The
Minim
twisted viciously and surged.

The intruder whipped past. They craned around to see it recede: a silver-brown cable hanging unsupported in space, there for an instant more, then gone.

Miya said quietly, “The Hangtree's dropped a sapling.”

A juvenile Hangtree? “That's good, isn't it?”

“Might mean I'm not crazy.”

Zeera said, “I'm correcting course now. That cost us some fuel.”

The parent Hangtree rose; become large; vast; a world in its own right, coming up too fast as Zeera turned the
Minim
for a final burn. Thrust pulled them into their seats, then eased. A vertical bar on the displays stretched, lit up in red, kept stretching, turned yellow.

Svetz asked, “What's that?”

“Hull temperature,” Zeera said. She turned the
Minim,
and they looked into a hot pink glare.

“Heat rays. Futz 'em,” Zeera muttered. “Did either of you see any kind of projections on the mid-trunk?”

“Sail struts,” Svetz said. “Down the trunk by no more than twenty klicks. Sail material harvested, struts still in place.” The glare of Softfinger heat rays washed out all detail, but he'd seen. “We can moor to those. Zeera, what about the heat cannon?”

“Can't hurt us, but projectiles can. I need to moor us
now.
” Another puff of thrust sent them downward, still closing with the trunk.

The heat rays touched wood. Red fog boiled out of the bark and closed around the
Minim
before the Softfingers turned their weapons off. Svetz looked for double-wok shapes in the red murk. What he saw was a man-built dirigible airship moored below them, much too close.

A final tiny push and they were up against bark, in a ring of light-sail stumps. Miya was already in the airlock. Svetz followed her through, his flesh shrinking from unseen high-velocity bits of metal.

Slowly, carefully, Miya showed him how to make knots that would come apart at a pull. They wound cables around the huge stumps, moored the
Minim
tight, then climbed back inside. The airlock held them both, intimately, as something like a rainstorm began: bullets ticking against the hull.

The sky lurched into motion.

The inner door opened. Miya moved briskly to her chair.

Svetz blocked the sun's flickering arc with his forearm. He watched stars whirling around him, the brighter twinkling of clustered light-sails, whirling Mars sinking away. A wooden structure built itself on one side of the
Minim,
and continued to flicker with motion.

“Studying
us,
” Svetz guessed. “They saw us disappear here. Zeera, could they detect us?”

“How would I know?”

Mars was a ruddy dot, not even a half-moon anymore. The sun was fixed, a glare among the mirrors at one end of the tree.

Svetz asked, “Miya, you had a plan. Are we still on track?”

“Me? Plan?” Miya laughed, then sobered. “All right. I'm trying to think like an orbital tower here, like a
tree,
Hanny. Where does a Hangtree want to go? It must have crossed interstellar space to get here. Why didn't it go straight to Earth?”

“Low gravity, high spin. Mars, not Earth.”
She'd
told him that.

“But Mars is mostly desert. Earth is mostly ocean. Why wouldn't a Hangtree want to zero in on the richest water-and-oxygen spectrum in the sky? Our problem is we got hung up on
seeds,
” Miya said. “A plant can bundle tiny bits of information into a million seeds. A Hangtree can't do anything that simple. Interstellar space is just too big to
find
anything by accident. Even a seed that got lucky wouldn't be anything more than a bit of meteor.

“It must have crossed space as a tether, already a hundred thousand klicks long and festooned with solar sails, all ready to move into place and take over a planet.” She looked at them. “Right?”

Svetz was reserving judgment.

“Ten thousand years on route, getting energy from starlight but using up its reserves of mass, getting more like a dried-out dead tree all the time. It leaves fat and arrives lean. Anything that migrates does that,” Miya said. “It finds a world and takes up orbit, maneuvering with the sails. Drops seeds. An anchor grove grows. The Hangtree drops a root. The grove sends up water and soil nutrients. The Hangtree sends down sugar sap. They feed each other. They grow.

“It picked Mars because Mars is easy. Earth makes a better garden, but two and a half times the gravity means a tree has to be longer and stronger.
Now
it's strong enough. It was almost ready to tear loose from Mars. Then we got here and war came swarming up the tree. All that dead weight tore it loose, or maybe it was just
ready.

“It's going to Earth.”

28

When it became clear that nothing was going to happen fast, Zeera and Miya went to sleep, leaving Svetz on watch.

*   *   *

The tree had made accommodation with the prevailing tide. Its down branch was pointed into the sun. Constellations streamed past, conveying a sense of progress, marking a year for every circuit.

There was motion on the tree.

The dulled silver elevator track was being stressed, stretched, pulled apart. Anchor points popped. Torn ends slithered away from each other, up and down the trunk. Then a wave of repair ran down the rail and left it intact and shining silver and flickering with traffic.

Mirrors at the tree's end points flickered endlessly. Bubble domes sprang up along the tree's up branch, then were replaced by more angular, more solid structures. Svetz could see their mutating silhouettes against the glare of mirrors at the up end.

Beehives formed along the down branch. Plumbing began to grow along the bark. Suddenly the pipes were shattered and most of the beehives became charred craters in the bark. It all began to grow again, like mushrooms.

Svetz tried to guess how many Martians, how many martian races, were still on the Hangtree. It seemed they'd built vertical cities, fought, then reached an accommodation.

The tree was maneuvering, going somewhere: the flicker of light-sails told him that. The
Minim
's instruments might have told him more if he'd learned to read them.

New light-sails were beginning to unfold on the old stumps around the
Minim.

The elevator track wriggled restlessly, now crooked, now straightening. Torn again, repaired again…?

Hours passed in the
Minim.
Svetz had lost count of the years passing outside. Sixty? Seventy?

Light glinted from Miya's eyes. She was awake.

He spoke his fear, lightly. “We
are
going to Earth, aren't we?”

“I'm sure it's what the tree wants.” Sleep made her voice gravelly.

“Maybe it's ready to cross to another star.”

Miya wasn't looking at him. Her fingertips glided over her instrument display.

Svetz said, “We've been between planets for something near a century. Whatever Martians are still with us must have made their peace with the tree—”

“They're here if they want to be. Any Martian would have had time to get back down to Mars.”

“What if they learn to steer the tree?”

“
There's
a nice thought.” Miya laughed. “They could take the tree to Europa. Let it pick up gigatons of water, bring it back to Mars, cut into the trunk and let sap bleed out. Fill up those canals!
We'd
end up at Europa with no fuel and nothing to eat. Pass me a dole brick, Hanny.”

He did that. Miya said, “Now, the FFD completely futzes up our inertial guidance, and the computer can't find our location because nobody thought to tell it about changes in the constellations. But I've graphed our insolation—that's the light that's been falling on us since we left Mars. Here.”
Tap.
Svetz's display changed. Sure enough, that was a graph. “Curve looks choppy, doesn't it? Sunlight should be more steady. Maybe all the mirrors screw it up. But see for yourself, Hanny, we're getting
twice
the sunlight now. We're going in toward the sun, not out. Anyway, the Earth-Moon system went past while you were talking, and here it comes again. See it?”

Svetz never could find anything that someone else had to point at. He said, “I'll take your word.”

“Are you awake?”

“I want some sleep, if you can take over.”

“Go ahead.”

*   *   *

Still asleep, or trying, he let both arms drift up to block a blue-white strobe. It almost worked. A fitful glare lit up his eyelids anyway.

When he opened his eyes, the
Minim
was in a bouquet of rippling mirrors.

The mirrors shifted languidly. Edges parted and closed again. He caught partial views of glare-white clouds forming and swirling and dissolving frenetically on a whirling blue background. A black shadow swept across …

Zeera saw that he was awake. “We haven't moved for a while. We thought you should be up when we turn off the FFD.”

“Should think so. Martians all around us.” Svetz loosed himself from the web. He was groggy. Free fall made him clumsy. “Good call, Miya. Earth. Did the tree touch down yet?”

“Not yet. It's dropped seeds. Showers of seeds, a dozen times in a dozen places. I think it must be waiting to see which anchor trees come up. We've been here two years and a fraction. We're not in geosynchronous orbit; we're drifting.”

“Can we finally check in with the Institute?”

“The talker doesn't work in Fast Forward. We'll have to drop out.” Zeera's forefinger reached.

“
Hold
it!”

Miya spoke soothingly. “Hanny, we're fine. We programmed the
Minim
for reentry. Those light-sail stumps weren't dead after all, so we're pretty well hidden from any Martians. We drop out, we use the talker to call present time—”

“Cut the
Minim
loose first! Miya,
we
can't see
them.
Take translators and blasters too. Are we all going out?”

Zeera laughed. “Translators? In vacuum?”

“If you find yourself wound in a net in some Softfinger pressure dome, Zeera, you will be glad you have a translator.”