Rainbow Mars

by Larry Niven

  Miya stopped in the middle. Svetz stopped too. There was no need to speak.

  Again it was as if the skin of a world had been inverted, and they stood at the center. But this world was not their own. The oceans were small blue patches on a world gone mostly red. The continental shelves were dry land. A blue worm wriggled the length of the valley that had been the Mediterranean Sea.

  Willy turned back. Misunderstanding, he pointed out a ridge that stood up from what had been the seabed of the Atlantic Ocean. “Are you familiar with Atlantis? Some saltland farmers found the ruins in Waldemar Four’s time. On your time line—”

  “We didn’t have technology to look that deep,” Miya told him.

  “Well, come on.” Willy forged ahead.

  Miya lingered. “Hanny, did you see? They’ve got canals.”

  Blue threads wriggled over the Earth. The largest followed the old rivers and the beds of the Baltic, Black, Caspian, and Red Seas, and the sites of the Great Lakes; but rectilinear networks branched out from tiny cubistic pumping stations on the old natural curves. Cities crowded around the remaining seas, hundreds of klicks below what had been coastlines.

  Antarctica was a diminished ice cap on a greatly expanded continent. Highways wide enough to see from orbit led across dry seabeds to Australia, Africa, South America. Svetz pictured trucks as big as tanker ships laden with freshwater ice.…

  They caught up to Willy Gorky near Whale’s cage, which was more properly an aquarium. He shared it with crabs and a seaweed forest. Whale held Svetz’s eye. You made us extinct. Now it’s your turn.

  “This is why we have to guard the Bestiary,” Gorky told them. “Every so often someone tries to break in. All that water! They must think it’s fresh, of course, but there’s enough fresh water in the Bestiary to … to…”

  Svetz turned around when Willy trailed off. Willy was on the ground. He looked dead.

  Svetz said, “These locks are beyond me. Miya—” Miya looked dead too, an angry and desperate ghost. They must all be seconds from death. “Willy? Sir! Do you know a code to get us into the cages?”

  Willy stirred. “Cages. Why?”

  “We need water!”

  “Ra Chen told me some of the codes. Which cage?”

  Svetz looked about him. The door to Whale’s cage was up a stairway. He didn’t want salt water anyway. Snake’s head lifted from his coils … Horse came to his feet, horn poised for murder … Rabbit seemed to be hiding, but Owl, housed in the same cage, watched from an artificial tree branch. Dog—

  “Dog.”

  “Woof. State your name first.” Willy’s head flopped back.

  They picked up Willy, one under each shoulder. Willy didn’t weigh much.

  Dogs crowded around the door, waiting eagerly to greet them, panting, laughing. They were of various sizes, colors, and breed mixtures. Miya shied back a bit, but Svetz felt no fear. He said, “Hanville Svetz. Woof!”

  The double door unlocked and they went in. Three dogs swarmed him, and one was Wrona. Another was sniffing Miya, unsure. They walked Willy inside and set him down.

  The air smelled wet. You could taste it on your skin: wet. A big dish of water stood half full and open to the air.

  They scooped water with their hands until their thirst was quieted. Then they dribbled water into Willy’s mouth, into his hair, into the collar of his shirt. He smiled and opened his eyes.

  Sitting with a dog under each arm, Svetz asked, “Willy, have you any idea what Wrona is doing in here?”

  “Dogs need water.” Willy’s voice was a bit slurred. “She has to be protected. What did you think, we’d send her home with you?”

  Svetz scratched Wrona’s ears. “We’ll fix it,” he said. She looked up at him in perfect confidence. “Willy, we’re dying. Right?”

  “We’re holding on,” Willy said. “The Antarctic ice isn’t gone yet.”

  “But we changed the past, Willy. The change shock is still coming down the line. I thought fifteen hundred years of intense natural selection would have shaped us for the dryness, but it isn’t going to be like that. When the time line adjusts, the human race will have been extinct for hundreds of years.”

  “Svetz … what did you do?”

  “We brought the World Tree to Earth,” he said. “It must have sucked up most of the water on Mars already. We busted it loose from Mars. It left a sapling behind in orbit. The sapling must have finished draining Mars. Meanwhile the Hangtree came to Earth and drained us.”

  “Wouldn’t it have come anyway?”

  Svetz was jolted. “Miya? Is he right?”

  “I don’t know.” Miya was starting to cry. “Of course that’s what a Hangtree would want, but … it wasn’t finished. Didn’t have all the water. On our time line the Hangtree must have waited too long at Mars. Something happened.”

  “What?”

  “Oh … Phobos? I wondered if the Hangtree’s trunk could oscillate in a harmonic rhythm with the inner moon’s orbit. Every time the moon comes past, the trunk would be off to one side. Hanny, it would be easy to disturb such a system. Close approach from an asteroid, or a solar flare pushing on the mirror sails, or just chaos in action. Leaving Mars, it would have to be dodging both moons. But I’m guessing, Hanny. Another possibility—”

  “Miya, Svetz,” Willy Gorky said, “the question is what to do now.”

  “Chop down the tree,” Svetz said.

  “That?” Willy gestured southeast. Though the World Tree couldn’t be seen from Dog’s cage, it was there in their minds. To think of destroying such a thing was ludicrous. In Norse myth, Yggdrasil wasn’t a part of the Earth. The world of mortals was a part of Yggdrasil.

  “Earlier.” Stubbornly Svetz went on. “When it first linked up, the trailing root wasn’t any thicker than my finger. If only we had a time machine!”

  Miya said, “Hanny, if you chop through the link, the tree’s still in geosynch orbit. It dropped lots of anchor groves. It’ll just link up again.”

  Svetz’s mind began to run in little panicky circles. When the Tree reached Earth it was already too late. We have to chop it before then, at Mars. Wait now, we did that. It came here. We can’t get to Mars anyway, an X-cage won’t reach that far, the Minim can’t lift from Earth.… Wrona’s fur under his fingers, the perfect trust in her eyes, were anchors to reality; but whatever reality might be, he was losing it.

  Willy said, “Chop off the top?”

  Miya said, “Ah.”

  “Right, then. Chop it with what?”

  Svetz said, “Wait. Would that work?” His mental mapping caught up and he said, “Of course it would work, you just have to chop off enough. Yes!”

  “Let’s have a look in the Armory,” Miya suggested.

  That got a quizzical look from Gorky, but Svetz felt he had his balance back. He said, “Of course all of this has to be done at a dead run. What’s out there is not much different from current Mars. Too dry for humans.”

  Wrona held off the other dogs somehow while they drank deeply and splashed their collars and shirts and hair. The dogs didn’t much like intruders at their water dish.

  Willy asked, “What about the Martians on the tree?”

  They looked at each other gravely. When nobody else spoke, Svetz said, “I can’t see a way to save them.”

  Miya nodded. Willy Gorky stood up, a little wobbly, and said. “The small X-cage is set and ready to go. Are we? All right, go.”

  * * *

  Somebody had brought in a big lifter platform. Good idea—Martians wouldn’t be able to walk—but it was unattended. Ra Chen and three techs were all in the Guide Pit. One of the techs was on her back with her knees and head propped up.

  Willy told the Armory door, “Willy Gorky, come to the arms of Victor Four.”

  A massive door opened. Svetz looked at what was inside the Armory. It was evidently a kinder, gentler age—

  Willy said, “I don’t know what you thought you’d find, Miya. We’re ready for riots, and of
course we’re ready for big animals, but not a major deconstruction project.”

  —It was also an age in which rioters might invade the Secretary-General’s Garden and Bestiary in search of water. The weapons locker held mostly sonic stunners: thirty or more handguns and six two-handed sonic crowd sprayers of a design Svetz had never seen. They looked to be heavily shielded against backstun.

  The net sprayer was a bulky two-handed thing. It would tangle an ostrich or an elephant, or hundreds of rioters.

  There was Space Bureau pressure suit armor for half a dozen. It too might double as riot gear.

  There was nothing like the blasters they’d had aboard the Minim.

  Svetz was used to a needle rifle. He took one. Miya and Gorky looked at him oddly, so he put it back.

  And now he was right out of ideas.

  “Incoming,” Ra Chen called.

  Routine announcement, but he wanted help. Svetz saw why. Another tech had passed out, leaving only Hillary Weng-Fa and Ra Chen himself.

  Svetz slid into the Pit.

  Nothing in the displays looked urgent. The large X-cage was being reeled in, passing minus two hundred AE, minus eighty, plus ten … Out on the floor, the extension arm faded a meter from the wall. At first glance you might mistake the end for a hologram washed out by sunlight. Keep looking and your eyes would try to … try to follow … Through long practice Svetz wrenched his eyes away.

  Plus two ten. Three hundred.

  Willy and Miya were at the Pit. Miya was holding a hand stunner. She said, “Hanny, we don’t have anything to cut a Hangtree with.”

  “I know.”

  “Now what?”

  Six hundred. Seven sixty.

  “Man the lifter, Miya. We don’t have anyone else. One thing at a time. That’s a little fast, Hillary.”

  Eight thirty. Eight ninety.

  “Too fast, Hillary!”

  “Yes, but what do I do?”

  Svetz showed her. The numbers slowed. Telltales showed that the excess heat was being dealt with. Going … where? Not the pond; that was gone. A radiator fin somewhere?

  Ten ninety. Eleven hundred.

  “Incoming.”

  Eleven five—

  The extension arm was blocked by a ghost, then a solid transparent shell.

  A variety of Martians had been plated around the shell. They wore pressure suits as various as their shapes. In the instant the X-cage came home, they all fell toward the Earth’s center. Now they were thrashing and trying to pick themselves up where gravity had dropped them. Svetz looked for Wilt and Zeera.

  A froglike entity with a pointed face occupied the control chair. Svetz found Zeera and Wilt in a cluster of red Martians. Their hands—futz, they were prisoners! And what was that pointing down the axis of the X-cage?

  Its size and placement made it hard to see—too big and too foreshortened—but only for that first instant. Under the big equipment bin in the ceiling, a tube of crystal and copper and silver ran nearly the length of the large X-cage. The back end was welded in place. It was a heat ray cannon longer than Whale, and the lens looked straight into the Guide Pit.

  Svetz jumped over the wall and ran. They’d left the Armory open. Svetz snatched up a two-handed sonic and ran at the X-cage. He was out of the line of fire, but next to the great glass door, as the doors began to open like flower petals.

  All the four- and six-limbed martian shapes were thrashing around trying to get to their feet, or trying to wave blades or long-barreled guns at the door. Bulge-eyed octopoids attended what must be the firing mechanism, which was a sort of cockpit. Svetz had no idea whether a heat ray would fire through the X-cage’s door or wall, or reflect. He guessed that they didn’t either. They waited.

  Miya was on the other side of the opening door, her sonic handgun ready.

  A green giant lurched into the bug-eyed cannoneers and sent them sprawling in a tangle of rubber limbs.

  Miya forced her hand inside the doors and began spraying sound. Svetz had to wait. One full second, and then he could poke in both arms and the crowd sprayer. He sprayed everything in the way, aiming for the back of the cannon, where the controls seemed to be, and where another green giant was wrestling with the first.

  The first must be Thaxir, but it didn’t matter. The crowd sprayer was not selective. He sprayed them both, and the two Softfinger octopoids who wriggled free of the wrestlers and were trying to reach the trigger cockpit. He was inside now, and he waded toward that, holding his aim on the cockpit. Alien hands and blades kept popping up in his face, but nothing around the cannon controls was moving anymore, and now he was there.

  Zeera and Wilt had wriggled away from their captors. He fired bursts around them, and around Miya, and nothing else seemed to be moving in the cageful of Martians.

  His arms were numb.

  These Martians were still conscious, Svetz remembered. They just couldn’t move, or answer, so he was talking to himself as he inspected the great weapon.

  “All right, now we have a heat ray. How the futz does it work? Cockpit and big attitude jets. Built for free fall. More plasma weapon than laser. Maybe it’ll cut the tree. Maybe. Futz, I think we can save the Martians! Willy—”

  Ra Chen and Willy Gorky were in the X-cage. Willy was pulling a red Martian woman out. He’d set the edge of the floater against the doorway. Svetz cried, “Willy, stop!”

  “What?”

  “Put her back. We can save them. Just leave the Martians where they are.”

  “But we’ve got them—”

  “And we want to keep them. We didn’t send the large X-cage back far enough in time. Look, Willy, we’re going to chop down the tree before they were rescued. The only way to keep them rescued is to take them back with us, because this time line is going to disappear.”

  Willy looked a bit sick, but he said, “Got it.”

  “Leave them in the large X-cage. We have to take that back anyway, because there’s no easy way to dismount the cannon—”

  Ra Chen said, “It’s set for the wrong time. Sixteen AE.”

  “We’ll have to reset it.”

  “That’ll take hours. Svetz, I really don’t think we have that long.”

  “I don’t either. And they don’t.” Waving into the X-cage. Earth gravity killed Softfingers quick.

  Ra Chen said, “Advise me then, drown you! Think!”

  The silence was a rustling of Martians. Sonic weapons set muscles twitching at random.

  “The small cage is set for the right time,” Miya said, “isn’t it?”

  “Yes?”

  “And you can set the large X-cage to meet the small one, can’t you, Hanny? It’s how you got Whale. Then—”

  “Stet, got it, thanks.” Ra Chen was on it. “Hillary, you and I can run the X-cages. Zeera, you take the small extension cage back. It’s set to drop out where the Minim’s FFD disappeared around minus three fifty AE. That’s where your team went into Fast Forward and came here. Then—”

  Hillary Weng-Fa said, “Wait now, Boss. You’re going to kill everyone in the universe?”

  “You’re dying now,” Svetz told her. “When we’ve done our job you’ll be restored to health.”

  “But it won’t be me!”

  “In a few hours it won’t be anyone, Hillary.”

  “I’ll take my chances! You think you’ll save yourself—”

  “Hillary.”

  “Boss?”

  “Most people will be in better shape after we’ve done this. Millions of people won’t be dead anymore. We’re all near dead, even if you’ve got too much courage to admit it.”

  Nice phrasing, but Hillary Weng-Fa wasn’t showing courage. “It won’t be me! I, I can’t help you do this.”

  “No, of course not. Go home, Hillary. Zeera, you and me. We’ll be running two X-cages. We can send the large X-cage back to meet the small X-cage on manual, soon as it’s in place. Are you up to it?”

  “Certainly.”

  Hillary cried, “Zeera,
you’ll disappear along with the rest of this!”

  “Willy, you’ll take the small X-cage back,” Ra Chen continued. “It’s set for the right timespace. There are only two things you need to do.” He stepped into the small X-cage and pulled Willy after him. “The chair swivels. This whole display on the left is remote controls for the large extension cage. On arrival, you punch this. It summons the large X-cage. If we didn’t need someone to do that we’d send it empty. Then pull this in the middle. That’s the go-home. I can’t see any way you can get in trouble, and it’s a futz of a ride.”

  “I’m in,” Willy said.

  “Now, Willy.”

  Willy climbed into the small X-cage. Zeera and Ra Chen took their places in the Pit. Svetz joined them, but he only watched. They were both better at this than he was. Willy watched them all with a look of wary anticipation.

  The small X-cage disappeared. The extension arm led off in a direction the eye could not follow.

  Ra Chen said, “Hillary, are you still here? Go home. Svetz, Miya, you take the large X-cage. What have I forgotten?”

  Svetz said, “Thaxir. Get her apart from the rest before they ball up.”

  Martians had fallen all around the control chair. Miya found a green giant and swore that she was Thaxir. It took three of them to pull her up the slope of the wall, away from the others.

  “What else?”

  Miya said, “Pressure suits! Ra Chen, I think that’s a plasma weapon. We’ll examine it on the way, but we’ll have to open the cage to use it. And question some Martians.”

  Zeera said, “Translators. The net gun and something to cut nets. More sonics. Net the trigger on the cannon and net the Martians and keep them apart, and spray a net over Thaxir. You want to keep them stunned, and you don’t want them wriggling loose, and you don’t want them to open the door or fire the cannon.”

  Ra Chen rubbed his temples. “Sounds like a lot. Anything else?”

  Miya lifted her sonic handgun and fired. Hillary, reaching into the Armory door, dropped like loose bones.

  “That’s all I can think of,” Miya said.

  “Get that stuff and get aboard.”