Critical Threshold Read online

  It seemed logical enough to follow the river ourselves when we began our trek into the forest. It would enable us to make what use there was to be made of the map, and we would presumably be retracing the steps not only of Dendra’s first human explorers, but perhaps of Dendra’s first mass exodus. If the colony had split in two—which still seemed to me to be highly unlikely—then the men who had left would almost certainly have gone north. To the south there was a relatively inhospitable mountain range and then a long drop into colder regions, while to the north there appeared to be vast plains of temperate climate and good soil.

  We elected to travel as light as was practical, the only really heavy items being the tent and a bulky power pack to supply both light and heat. In accordance with UN recommendations we took only one substantial weapon—a rather clumsy rifle equipped to carry three different clips of ammunition, two of which consisted of anesthetic darts of varying strength and only one of which actually held lethal missiles. In the interests of self-protective convenience, however, we also carried small handguns with parabolic reflectors instead of barrels. When fired they emitted a loud bang and a brilliant flash—intimidating enough to scare away any unwelcome visitors, and even to blind them momentarily. These, like the rest of the necessary equipment—the radio, a portable lamp and the medical kit—were conveniently light.

  The most precious thing we carried was the book.

  When we left, the usual half-dozen children followed us across the fields and watched us climb over the wall. We had to climb—there was, in fact, no gate. Their expressions of patient wonder changed hardly at all as they watched us go. But they didn’t come to the wall so that they could watch us move through the scrub to the green curtain where the foliage of the ancient forest dipped close to the ground. The wall, to them, was a conceptual barrier as well as a physical one. Once beyond it we were out of their world.

  I waved to them from the top of the wall, before dropping out of sight. Surprisingly, one of them waved back. It was an oddly reassuring gesture.

  We crossed the area where the forest was regenerating with some difficulty, for the ground had been left very uneven by the retreating colonists, littered with dead wood and some stones quarried from a cliff face a couple of miles away. Stiff-stemmed plants like bracken concealed much of the unevenness, and it was by no means easy to force a way through it. But the pseudo-bracken had a role to play only in the juvenile forest, and once we were into the forest proper the going became much easier. The tree trunks were much more widely spaced, and the ground between them was carpeted with plants which were not so tough and did not grow so high.

  Small birds fluttered out of our way but showed no specific fear of us. They were content simply to stay out of reach. There did not seem to be so very many at a cursory glance, but our ears told us the truth which was veiled from our eyes—that there was, in fact, a great multitude hidden by the green ocean of the forest canopy. The trees, even here, grew between fifty and a hundred feet tall, and the boles of the most ancient specimens, knotted and gnarled, must have boasted a girth of thirty feet or so. Each tree extended its branches so as to barely touch the branches of one or two of its neighbors, so that sunlight crept down to the forest floor only through the strangely curved slits that remained. For the most part the lowest branches were eight or nine feet from the ground, but were virtually denuded of leaves save at their extremities. Nevertheless, the crown of each tree was a forest in its own right, on a tiny scale, hiding and sheltering birds, and perhaps beasts as well. The bark of every tree was covered by a waxy substance, which seemed lighter in color and softer in texture on the lesser trees, but blackened and set as hard as adamant on the oldest. This substance was fireproof, and though the internal wood of the trees burned well enough, forest fires could not spread on Dendra.

  Because of this waxen coat, which often seemed so slick as to be polished, the insects moving on the tree trunks tended to be rather obvious. Some of them attempted to counterfeit the appearance of the wax in their own external aspect, but for the most part the legion of small flying and creeping things went in for flamboyant dress rather than cryptic coloration. Large beetles with wing cases decorated with gaudy patterns of brilliant blue and yellow were common, and even smaller bugs with bodies little bigger than pinheads often boasted such violent crimson coloring that they looked, when massed, like countless drops of blood. The most striking members of the forest population, however, were the butterflies. On Earth, the term “butterfly” refers to a relatively small range of genera which are all anatomically similar even if their wing patterns often vary strikingly. Other, closely related, creatures we call moths. There are, however, difficulties in re-applying Earthly terminology to alien life systems, and you always find some instances where the transfer is inadequate. Dendra’s butterflies were one.

  In stark contrast to Floria, where nothing flew at all, Dendra went in for flying creatures on a big scale. In a forest, this is not so surprising, especially a forest covering a whole world. The same modes of flying that had been developed on Earth had been developed here, but insect flight—and especially that variety of it practiced on Earth by butterflies and moths—had been much more heavily exploited by the evolutionary pattern. Instead of a few closely related genera the term ‘butterfly,’ on Dendra, had to do for a great range of quite distinct families. The differences, of course, were largely to be observed in the type of body to which the paired, colored wings were attached. Some of the insects had bulbous, colored bodies, some had hardly any bodies at all, some resembled Earthly butterflies while still others boasted amazingly complex jointed structures, waxen in texture, which were equipped with tentacular limbs. Many had no legs whatsoever, and a significant fraction were eyeless.

  It can be argued that for such a profusion of types, the one term is hopelessly inadequate, but the only way to be able to speak of alien life forms at all is to co-opt the vulgar, general terms in use in common parlance and apply them where they can be made to seem appropriate. Even on Earth, such commonplace nomenclature is far from scientifically exact, so the ineptitude of the method is not really an argument against it. Trouble arises where common Earthly names are generally applied only to one species or a similar group of species—thus it is easier to use words like butterfly, insect, mammal and crab than it is to use lion, elephant, or even goat—but for the most part one can acquire a comfortable descriptive power over an alien life system by the judiciously casual redeployment of terms. Thus, the hosts of Dendra’s population of multicolored flyers became butterflies, although in themselves, and by scientific standards, they were so much more.

  The forest would have been beautiful without the butterflies, but it was the butterflies which really gave that beauty an obviously unearthly quality. They were everywhere, and at a casual glance you could get the idea that they were all unique, every one an individual living gem with its own particular artwork. The colors were often harsh, and the patterns lacked subtlety—bold stripes, blotches and heavy borders were as common, if not more so, as detailed, exactly-planned color schemes—but the effect of the collective phenomenon was dazzling, and, to my mind, quite superb.

  The birds which we saw were mostly small, and the great majority of them, like the butterflies, were brilliantly and profusely colored. It was difficult to estimate by the evidence of the eye how many species there were in the vicinity, but our ears assured us of the diversity. Though the foliage hid large numbers from sight it was no barrier to sound. The pitch and complexity of the calls sounded by the birds was similarly multifarious. I could not honestly say that the total effect was musical. Individual songs might be tuneful and pleasant, but in the competition to be heard there were a great many notes that were harsh and strident.

  We saw no more than the merest glance of creatures that were furred rather than feathered. That mammals were present in some abundance I did not doubt, but they made far more use of the cover offered by the vegetation. We caught glimpses of squirre
l-like animals ducking out of sight among the branches, and there were droppings on the ground testifying to the fact that the trail we used was in constant use by other beasts which might range in size from the dimensions of a rabbit to the bulk of a pig. In actual fact creatures distinctly similar to the wild pigs of Earthly forests were just about the largest mammals on Dendra. They were omnivorous and undoubtedly used to having their own way but were—according to the colony’s guide-book—not inclined to attack people. The most aggressive predators in this particular locale, according to both the survey reports and the book, were a group of species resembling medium-sized members of the Earthly cat family. The whole group had been dubbed “panthers” for convenience, although most were blotchy brown in color.

  I was surprised, as we went into the deeper and more luxuriant forest in the valleys, that there still remained a good deal of light by which to see what was going on around us. Evergreen forests on Earth—especially mono-cultural stands—tend to be dark and gloomy, and the forests of Floria had been designed with such economical perfection that their paths were all but pitch dark. Dendra’s forest was, however, more varied and more relaxed. The trees were comfortably spaced and their shapes were elegantly irrational. Most seemed to be very old indeed. The trunks varied in color from a brown so light as to be almost ochreous yellow to a deep blue-black. Most were streaked Or mottled, often with metallic colors—copper and gilt. Because of the waxy tegument it often seemed that with the aid of a polishing rag a dedicated workman could make each tree gleam and shine like a vast, ornate living crystal.

  The soil was moist and soft, thick with humus and scattered with loose grass and hummocks of moss or fungus. Flowering plants were common, but did not grow so profusely as to invite comparison with the birds and the insects. They were virtually all insect-pollinated and boasted blooms sculptured into all kinds of complex shapes, but for the most part they did not go in for riotous color. The pastel yellows and pinks seemed distinctly conservative by the standards set among the gaudy flying creatures. They attracted pollinators, it seemed, largely by scent. Sensory priorities were different here.

  I guessed that a good many of the eyeless butterflies lived very largely by their sense of smell, experiencing the world as an ocean of organic traces. Some of the larger species might use sonar to guide them, but not the smaller ones. When you’re tiny it doesn’t matter much if you fly into a solid object, because you fly so slowly and the energy of collision is so very slight. Despite the fact that our superior eyesight made it easy enough to see our way in the forest the intensity of the light was such that evolution had favored different abilities in the species which had evolved to occupy this environment. I wondered whether the population of the forest underwent a considerable change after dark, with the birds resting and the bats emerging.

  The air was humid and it seemed rather warmer within the forest than it had on the bare hillside of the settlement. Even the tree trunks seemed warm to the touch and it occurred to me that a certain amount of metabolic heat probably was being generated there. Down here, half-enclosed by the network of leaves and branches, was an environment so still and stable that it must be amenable to a degree of control. The survey team had commented on the constancy of the temperature in the forest and the narrow range of humidity. The forest had been here for millions of years, undisturbed save for movements of the ground itself. The whole system was integrated, and the whole environment under a form of collective homeostatic control. The forest was in many ways like a vast organism—a warm-blooded organism maintaining its own optimum internal environment.

  Could it possibly be, I wondered, that the colony had failed to co-opt Dendran species to their own use because outside of their inordinately complex collectivity the organisms did not thrive? Or, even worse, underwent certain changes affecting their chemical makeup? Under different circumstances, I would have looked at the idea long and hard, but for that particular moment I filed it away. There was no time for dogmatic thinking. There was so much to see—so much that demanded the attention of my eyes and my mind.

  But it was an idea I would have to return to.

  CHAPTER SEVEN

  We made rather less progress in the morning than we might have, bearing in mind that the going was easy. We were forever pausing to look at plants, to watch butterflies, to look up into the trees at shy birds and their nests, to stir at thickets where creatures might be hiding, in pursuit of faint rustles we never quite traced to living sources. All this was, of course, primarily my fault, but neither Karen nor Mariel made any objection. They did not seem irritated, being eager enough to look themselves. Their interest was purely aesthetic, without any ulterior scientific motives, but there was a great deal for them to enjoy.

  By midday I felt slightly heady. I didn’t know whether to attribute it to the oxygen in the atmosphere, the organic traces in the air, or a purely subjective elation brought on by the surroundings. I guessed that all three might be true to a degree, but that the last was probably the most important. Feeling elated isn’t usually a straight physiological reaction to chemicals in the environment. Feeling is something that happens in the mind, with or without the body’s instigation.

  I felt intoxicated because this was what it was all about, for me. This was what I’d come out to the stars for. Alien life, on its own terms, the product of alien processes; whole new worlds of living things, shaped by evolution to explore the same possibilities according to a new pattern; living things which the words I’d brought from Earth could never quite describe or conquer, needing a whole new universe of thought to understand. That’s what it was all about. Up on high among the myriad fluttering wings of the colored insects were the fluttering wings of my imagination. And that was where they belonged.

  It wasn’t, of course, a perfect Garden of Eden. It had snakes a-plenty, although I hadn’t seen one yet. Some of the insects were bothersome. None were adapted for feeding on human blood but some adventurous types were willing to have a go, and many secreted corrosive or irritant substances when touched. We accumulated our fair share of minor skin complaints as we marched, and though our medical resources were easily up to coping we couldn’t quite overcome all the little trials and tribulations.

  But there are no Gardens of Eden this side of the grave, and no one expects them. We took the forest as it came, snakes and all. It would take far more than a few minor drawbacks to destroy the fact that in opening up the colony worlds the starship had restored to humanity the whole vast concept-space of Utopian dreams. Even the failed colonies couldn’t detract from the infinite possibilities, the infinite potential, that star travel had opened up for humankind.

  The stream which we followed flowed slowly. It was surprisingly deep, for although it was generally no more than a foot or two wide I couldn’t find the bottom with a branch nearly as long as my leg. I judged that the rock beneath the soil must be soft, and that the water had, over the ages, hollowed out a considerable groove.

  We rested when we finally reached the river into which the stream flowed. By then it was mid-afternoon. The river, too, was placid and sluggish. The lower branches of the trees leaned over its banks and sometimes trailed the tips of their leaves upon the surface. There were occasional rafts of weed—wide, lobed leaves and bowl-shaped floating blossoms like yellow water lilies. There were no crocodiles, but as we arrived I saw a couple of small darting lizards scampering over the rafts toward the bank, seeming to run on the water where necessary. There were legions of tiny frogs, green and yellow, clinging to the rafts and sitting on the bank close to the spot where we set down our packs. Unlike the more excitable creatures the frogs ignored us, remaining aloof and unintimidated.

  I stood by the edge and reached out with the branch which I had been using as a staff to touch and stir things of interest, and dragged its tip through the water, sending large ripples surging out toward the rafts.

  I looked up at the tall trees. Their topmost branches were driven by a steady, strong wi
nd, and all the trees seemed to have grown to accommodate the wind. Their ultimate growing points were directed not at the zenith but almost parallel to the ground, like flags waving in the violent airstream. And yet there was hardly a breath of breeze down here, at the surface of the river.

  I realized that the wind in the treetops made a curious sound: a soft susurrus like the sound of blood in human veins magnified a thousand times. As a noise it was not noticeable, drowned out by the cacophony of the birds, but when I strained my ears to hear it I could find it ever-present beneath the irregular riot of birdsong. It was a gentle sound, a background which testified to the continued life of the whole forest, on a timescale of its own, in which the momentary twittering, even the transient lives of the birds, was negligible.

  Struck by the contrast between the movement in the forest roof and the stillness of its floor, I seemed to possess once again some kind of intuitive insight into the nature of the forest and its life. It was so much bigger than a man, or a thousand men. Its affairs transcended theirs, ours. Fourteen hundred men and women had come to claim this world, to take it as their own, with the arrogant assumption that the forest could simply be chopped down as and where they pleased, and cleared out of the way. As it had turned out, it had not been possible. Without having the slightest idea why, I was not, in that particular moment, surprised.

  The olfactory analysis made by the survey team had analyzed everything except the smell of the forest. Perhaps the whole survey report had analyzed everything of the forest but the forest itself. Perhaps the forest as a whole was so much more than the sum of its parts that the whole philosophy of human scientific analysis, taking things apart, descending further and further into a miasma of effects in search of tiny primal causes, was incompetent to deal with the forest.