What had happened, therefore, was effectively a devolution or degeneration from artificial systems to living ones. I know that seems almost crazy, given that we generally think of living systems being far more ordered than non-living ones, but the builders' biotechnics had been more sophisticated than living systems. Even something as primitive (in these terms) as the Tetrax artificial photosynthesis systems up on level one would, if left to its own devices, eventually give way to "natural" grass. Think of it not so much as non- life degenerating into life, but as the delicately-bred plants in a garden, adapted not simply to reproduce themselves but also to serve the purposes of the gardeners, gradually evolving into coarser—but inherently hardier—weeds.
A mixture of guesswork and inference suggested to me that some of the old inhabitants of Skychain City were being relocated to lower levels, where they were being herded into the ruins of ancient and long derelict cities to begin the work of refurbishing them for their new would-be masters. For the Tetrax, especially, it must have been like being sent back to the Stone Age. As we crossed a particularly bleak plain on twelve I wondered whether there was some kind of testing going on. Maybe the invaders wanted to see whether the Tetrax were clever enough to find out how the systems built into Asgard's structure could be made to function again, even after a vastly long period of disuse and decay.
Further down, the rot that had claimed the higher habitats seemed not to have set in—or not to have progressed so far. But there were other complications.
Until we reached fifteen I had assumed that all the levels would have much the same atmosphere. The atmospheres of almost all humanoid homeworlds are very similar indeed, the relative percentages of nitrogen, oxygen, and carbon dioxide being a cleverly-maintained optimum. Planetary atmospheres, of course, are the creation of life, and because all the humanoid homeworlds share the same chemistry of life, they share the same ideal conditions. Their ecospheres adapt to produce and conserve those conditions, in much the same way that homeostatic mechanisms within endothermic organisms produce a constant internal temperature.
There are one or two galactic humanoid species who breathe air that the rest of us would find uncomfortable, but for precisely that reason they aren't fully integrated into the galactic community. There are life-systems that have alternative chemistries, but they shape up very differently from the kind of life-system that produces humanoids. You do get life, of a sort, in the atmospheres of gas giant planets—even gas giants as cold as Uranus—but it doesn't produce anything like the range of organisms that DNA can produce, and as far as I knew no one had ever found evidence of anything in such a system as intelligent as an insect, let alone a man.
Thus, I was very surprised to find that in a big airlock on level fifteen, our little party boarded a vehicle which looked more like a gigantic bullet or a wheeled starship than a car, and that when we went out into the open, we found ourselves in a real pea-souper of an atmosphere.
For a few minutes, I simply watched in astonishment as the coloured fog roiled around the thick windows, stirred into activity by the velocity of our passage. It was a dingy green colour, lit from above by a sky no more than fifteen metres above us. The green wasn't uniform, though: there were coiling wraiths of purple and indigo, like gaseous worms, and bigger, paler shapes that reminded me of old- fashioned images of immaterial spooks and spectres.
I could tell that Jacinthe Siani had seen it before, but not often enough to get entirely blase about it. Sky-blue and the troopers were as bored as they could be, though.
"What is it?" I asked Sky-blue.
"Mostly methane, hydrogen, and carbon oxides," said Sky-blue, morosely. "Some helium, many longer-chain carbon molecules. Very high pressure. We have to be careful with the locks. If the atmospheres get mixed, they react. Sometimes explosively. We don't know any other way through. Our maps are incomplete. We were fortunate to be able to locate a way up as quickly as we did; an environment like this might have been a barrier for many generations. The first one our forefathers discovered was the boundary of their empire for a long time, but we can now move about freely in such habitats, and we find certain uses for them."
"Is there life here?"
"Of a sort. Nothing that troubles us."
"I don't suppose you have a theory as to why your ancestors should fill some of their cave-systems with alien atmospheres?"
Before he could answer, the older man cut in with a few sharp remarks in his own tongue. Sky-blue favoured me with a dirty look, and I figured that he'd just been reminded that I was a spy and an enemy. I decided that it would be diplomatic to ask fewer questions.
By the time we left fifteen, I was ready for more surprises. Indeed, I was eager for them, if only to take my mind off what might be awaiting me below. For that reason, all the levels I numbered in the twenties were disappointments. They certainly weren't dead, and I didn't get the impression that they were markedly decayed, but the territory we crossed was empty. The skies were bright, and the vegetation seemed reasonably lush, but there was no evidence of sophisticated machinery except for the vehicles on the road, and the only sentients I saw were the pale-skinned invaders.
I could see plenty of pillars holding up the ceilings, but I couldn't see any blocks filled out with doors and windows. I knew, though, that we were seeing only the tiniest slice of each habitat, and that every one of them would surely be as big, and might well be as various, as an Earthly continent. It was as though I was trying to judge the nature and complexity of the Earth from a twenty-kilometre drive across a randomly chosen part of Canada. The best sights these levels had to offer might be awesome indeed, but it was entirely possible that the invaders had never yet caught a glimpse of them, having only skated quickly across the surface, more eager to find doorways to other levels than to explore fully those which appeared harmless and useless to them.
When we stopped to sleep, at a way station on what I took to be level twenty-nine, I was beginning to fear that Asgard might not have much more to show me. Wouldn't it be ghastly, I thought, if the Centre turned out to be no more exotic than Skychain City—or the microworld Goodfellow? There is no more horrible way that any mystery can be resolved than by dissolution into ironic anti-climax.
I consoled myself with the thought that we were a long, long way from the Centre yet—and with the knowledge that the reason I was being taken on this little trip to the heartland of Invaderdom was that I had already been shown proof that there were more things in Asgard, as in Heaven, than had hitherto been dreamt of in the invaders' poverty- stricken philosophy.
But could I, I wondered, interest them enough to persuade them to let me live?
16
The levels I numbered in the thirties were much brighter and more crowded than those in the twenties. Every time we emerged from one of the buildings that housed the connecting shafts, we came out into thriving city streets—wide roads with floor-to-ceiling facings, pavements, shops. This, I inferred, was the heartland of the invader empire; these were levels they had colonized in the distant past. I couldn't tell which was their home level, and my companions were not answering questions. Sky-blue and the senior officer had been arguing again, and Sky-blue was rather tight- lipped. Jacinthe Siani was keeping her distance from me, probably because she wanted to impress upon her new friends that she was solidly on their side.
I saw very few people on the streets who belonged to any other race than that of the invaders themselves, although there were far more females visible now, and far more civilians. The range of physical variation within the neo-Neanderthaler species was unusually small. I guessed that they were all descended from a relatively limited gene-pool; that would fit in with the popular theory that Asgard was some kind of Ark, whose many habitats had been set aside to be populated by the descendants of a favoured few individuals. Maybe all the invaders were descended from a single Adam-and-Eve pair, though they had now such a vast population that they had filled up several other habitats in addition to their
allotted Eden.
Obviously, such colonization had not been a mere matter of moving into empty space—they would hardly possess armoured vehicles by the millions and an army which seemed to involve ninety-nine out of a hundred of the adult male population if they had only discovered virgin territory. What I could see in the streets didn't give any indication of what had happened to the conquered races. The few exotic individuals I saw might conceivably have been slaves—or the enfranchised relics of populations—that had been all but wiped out.
As we cruised the city streets I amused myself with a little speculative mathematics.
Suppose, I thought, that the pale-skinned pseudo-Neanderthalers currently filled twenty cave-systems, each with a land area not much less than the land area of Mother Earth. With abundant food production they could be doubling their population every forty or fifty years. That implied that they would have to take over another sixty cave systems in the next century, and another four hundred and eighty by the end of the following century. How long would it take them to fill Asgard? How long would it take them to bump into someone who would put a stop to their game? And if Asgard were really millions of years old, why hadn't one of its races already expanded to fill the whole macroworld?
I tried raising such issues with my captors, but the man with blond hair was sulking, and refused to talk. He had been forcibly reminded that his job was to transport me, not to enlighten me.
Below forty, things began to change again. The invaders seemed to have had every bit as much difficulty going downwards from their local area as they had going upwards. Once again, their cities were replaced by much more limited roadside developments in less promising territory. But these lower levels weren't all dark and they weren't all bleak. On the contrary, many were brighter, hotter, and full of life. If the topmost levels could be reckoned tundra or steppe, these were jungle, swamp, and savannah.
On one particularly long trip—at least sixty kilometres— from one downshaft to the next I sweated so much that I longed for my lost cold-suit, with its careful temperature control. We were using an armoured car here, as we did on most of the levels that were not fully civilized, and the way the hot light beat down on the metal from the thirty-metre ceiling made it feel like an oven.
The area on either side of the road had been sprayed with some kind of herbicide, and new growth was only just beginning to creep back into an area whose earlier plants were all browned and desiccated. In the distance, though, we could see trees which reached up almost to the ceiling, spreading vast palmate leaves in a horizontal array to soak up the intense radiation almost at source, so that what got through to the lower layers was a crazy zigzag of thin shafts. I couldn't believe that the lush, strange undergrowth beneath the trees was wholly sustained by the interrupted light, although it was certainly well illuminated by it, and I concluded that much of the ground-hugging vegetation was thermosynthetic, leeching energy from the ground itself.
I'd never seen natural thermosynthetic organic systems before, and was surprised to see that they were not fungus- white, as I would have expected, but patterned and multicoloured in all kinds of bizarre ways. Like the flowering plants of Mother Earth these thermosynths had evolved in collaboration with insects, and they signalled to their pollinators in every possible way, appealing both to the visual and olfactory senses.
This was a very noisy forest, full of fluting sounds that I
initially assumed to be the calling of birds, but in a rare few minutes of conversation Jacinthe Siani remarked that in this ecosystem even the plants had voices, so intense had the competition to attract insects become. Here, she said, there were also fat flightless birds that mimicked flowers both physically and musically, in order to entice their prey into their hungry beaks.
I wondered whether the invaders had located the machinery that controlled temperature in these habitats, and why they hadn't simply turned down the thermostat to make them more hospitable. I couldn't believe that the neo-Neanderthalers had simply decided, like good conservationists, to leave this system the way it was in order to avoid precipitating an ecocatastrophe. It seemed much more likely that they had left it the way it was because they didn't know how to change it. They really were like a bunch of Neanderthalers on the streets of twenty-first century New York; they could pass for locals by putting on clothes, and could make a living as muggers with their own rough- hewn weapons, but they didn't know how anything worked.
But where were the zookeepers who should have made sure that these savages couldn't break out of their own allotted cage? Where, oh where, were the Lords of Valhalla?
As we traversed another of these tropical demi-paradises, I wondered what kind of sentients lived here. I was reluctant to conclude from the fact that I hadn't seen a single humanoid flitting among the bushes that these systems were just gargantuan vivaria. Clearly the invaders hadn't colonized these levels to any significant extent, but they could easily have built themselves a reputation for violence sufficient to make the locals very discreet. I fantasized about peaceful pygmies, tribes of lotus eaters, and about clever fellows who had invented musical instruments in order to charm the butterflies and the bees.
Further down, things got stranger still. I was glad to find that there wasn't a simple temperature cline determining the distribution of levels. Had it been the case that the levels started at absolute zero and had got so hot by fifty that they could no longer sustain life, I would have become pessimistic about the prospect of finding much more of interest. But the gravity had barely begun to weaken here, and I knew that the balmy arena in which I'd fought my duel with Amara Guur was much lower down.
Below the tropical regions there were cooler ones whose life-systems seemed much less fervent. Some looked ripe for colonization, but showed even less evidence of invader penetration than the tropical hothouses—and the invaders we did see were mostly wearing masks and protective clothing. We weren't—but we were in a vehicle that I judged to be very tightly sealed.
My companions wouldn't tell me what it was about levels forty-three and forty-five which made them so hostile to invasion even though they looked so innocent, but the masks and suits brought to mind rumours of galactic explorers who'd found lush worlds which turned out to be biochemically booby-trapped in some way. Where many humanoid species are gathered together, travelers' tales are a penny a hundred, and only one in a hundred has a grain of truth in it, but I'd listened to a lot of them, partly because they were fun and partly because they did at least convey some sense of the strangeness of the universe.
You might think that because all "Earthlike" planets have the same biochemistry, and a very similar range of major-groups of life-forms, one would be pretty much like another. That's true—up to a point. I've been told that even a seasoned galactic traveler might never see anything to convince him otherwise. (Though few humanoids ever visit one another's homeworlds; they visit one another's home systems, but in a civilized solar system there often isn't any real need or incentive to go down into a deep gravity well. A well-travelled galactic might have visited twelve or fifteen systems, but it's a very rare tourist who has actually set foot on more than three actual planets.)
The really exotic worlds are, of course, those on which humanoid life failed to evolve, or on which it evolved in a very different ecological context—and those worlds are often hostile to visiting humanoid life at a very basic level. It's not just that the locals will throw spears at you—it's that the local organics are poison through and through. The habitats through which we passed on what I took to be levels forty-three and forty-five might have belonged to this type, though I couldn't for the life of me see any obvious clues as to why they were so dangerous. The vegetation was still green, and most of it still looked like trees, bushes, grasses, and flowers.
Forty-seven and forty-nine had been extensively colonized, and there were thriving invader communities beside the roads on which we drove, though the temperatures were still on the high side. Fifty, although
we saw only a brief stretch of it, was a real wonder. It was very dimly lit, although the light was uniform—resembling a very cloudy twilight rather than a starlit night—but it was very warm, and it was home to a rich life-system that was presumably almost entirely thermosynthetic.
It wasn't easy to imagine a kind of planet—or a locale on a planet—where these kinds of conditions could occur. Maybe on a planet with perpetual fog and a steep axial tilt, in a region of considerable volcanic activity, there could be something like this, but it was difficult to imagine any such region being stable long enough to develop a rich flora and fauna.
One would expect there to be no colour in this kind of ecosystem, with the dim light encouraging only shades of grey. But that wasn't the case. Many of the plants here produced coloured fruit and flowers that they lit themselves; it was a world of Christmas trees with inbuilt bioluminescent fairy-lights. Many of the insects, too, carried around their own lights—wherever I looked there seemed to be clouds of fireflies, and the ground was ribboned by the lights of glowing worms.
In a way, I realised, what was happening here was a curious inversion of the characteristic pattern of life on Earth. There, light provided the fuel for the ecosphere, and sophisticated organisms made their own heat. Here, heat was the basic fuel, and the cleverest organisms made light for communication— perhaps as casually as Earthly creatures made odours. I had never heard rumour of anything like it, and I found it entrancing, but my bored fellow travellers hardly gave it a glance through the sealed windows of the car. There were a few buildings along the road we traveled, but no pedestrians. I guessed that it was probably another of the habitats where the invaders needed filter-masks to breathe safely.
Asgard's Conquerors Page 12
