I found a row of terminals and slid into a booth. It took only a moment to register with CORDCOM. My card disappeared into the slot, then rolled out again, overprinted with a yellow stripe. A large C in a red box had also been printed in the upper right corner. Was that it?

I cleared and punched for Directory, Lieutenant Colonel Ira Wallachstein.

The screen flashed: SORRY, NOT FOUND. Huh?

Maybe I had miskeyed. I typed it again.

SORRY, NOT FOUND.

Well, that was ... weird. I called up PROJECT JEFFERSON next, tried to list its personnel.

SORRY, NOT AVAILABLE.

Tried the Denver Area Military Directory. He wasn't listed there either.

I sat puzzled for a moment, wondering what to do next. I scratched my head. Why would Dr. Obama give me a package for somebody who wasn't here? Or maybe this Colonel Wallachstein had moved on and hadn't let Obama know? Maybe I should call Dr. Obama and ask. No, something told me not to.

I took the box out of my pocket and looked at it. There was nothing extraordinary about it, just a one-piece lightweight unit. Rounded corners. No markings, other than the printed keyboard and the lock. Not much rattle to it either. I had to think about this. I didn't want to destroy it. Not yet. That would feel like failure.

I slid it back into my pocket. Maybe tonight, back at the barracks. Maybe I'd missed something obvious.

I cleared the board and called up the day's conference schedule. The general session on Chtorran biology and behavior began at ten o'clock. Apparently it was a weekly session. I scanned the rest of the calendar, hard-copied it, logged off and went in search of breakfast.

I had bagels and lox and strawberries and cream. I ate alone, and I was still in better company than Ted.

TWENTY.

THE MAN at the podium looked unhappy.

There were too many empty seats. The auditorium was only a third full.

I hesitated at the back of the room. The audience had already begun to segregate themselves into sections.

The military attendees were seated up close, but on the sides. I hadn't realized it was possible to sit at attention. The funnylooking types were all in the first five rows. Of course, I'd never been to a convention where it hadn't been so. The serious types scattered themselves in the center of the room. The turbans and the burnooses-and there were an awful lot of them-were milling in the aisles, chattering away at each other as fast as they could, ignoring the frowning man on the dais.

The room roared with the noise of a thousand separate conversations-a babbling torrent of words. Didn't they realize how loud they all were? Each one was shouting to be heard above all the rest, and as each one raised his or her voice, all the rest became correspondingly louder too. It wasn't hard to see why the man at the podium was so unhappy.

I found an empty row halfway to the front and took a seat near the center. I put a fresh clip into my recorder and slipped it back into my pocket.

The unhappy man stepped to the edge of the stage and whispered something to an aide, the aide shrugged, the man looked unhappier. He checked his watch, I checked mine-the session was already fifteen minutes late. He stepped back to the podium and tapped the microphone. "Gentlemen? Ladies?" He cleared his throat. "If you would please find seats, we can begin-?"

It didn't work. The noise of the conversations only increased as each speaker shouted to make himself heard over the public address system. I could see that this was going to take a while.

"Delegates? If you please-?" He tried again. "I'd like to call this session to order."

No one paid attention. Each and every one of them had something so important to say that it superseded every other event in the auditorium.

The unhappy man tried one more time, then picked up a tiny mallet and started striking an old-style ship's bell that was perched on top of the podium. He hit it four quick times, then four times more, then again and again. He kept on striking it, over and over, a steady rhythmic dinging that could not be ignored. I saw him looking at his watch while he did it. Apparently he'd been through this before.

The groups began to break up. The various conversations splintered and broke off-they couldn't compete any longer-and the partic.i.p.ants began drifting into their separate seats. The only conversation still going full bore was one between three deaf women--or maybe they were interpreters-in Ameslan.

"Thank you!" the unhappy man said at last. He touched some b.u.t.tons on the podium in front of him and the screen behind him lit up with an official-looking announcement. It repeated itself every fifteen seconds, each time shifting to a different language: French, Russian, Italian, Chinese, j.a.panese, Swahili, Arabic-I couldn't identify the rest. The English version said: "English interpretations of foreign language speakers may be heard on channel fifteen. Thank you."

He waited while the various delegates inserted earpieces or put on headphones. They rustled and gobbled among themselves, each one taking an impossibly long time.

Something on the right caught my eye-Lizard! Major Tirelli! She was on the arm of a tall black colonel; they were laughing and chatting together as they found seats three rows forward. I wondered if I should call h.e.l.lo, then decided against it. It would probably only annoy her, and besides the auditorium was filling up now and it would be conspicuous, and probably embarra.s.sing. I wondered if I should save a couple of seats for Ted and Dinnie-except I didn't want to-until finally the question was answered for me when a dark, handsome woman sat down on my right, and a second later, a pair of lieutenants took two of the three seats on my left. The handsome woman was in a lab coat and was carrying a clipboard. She switched it on while she waited and began reading through some notes.

I took my recorder out of my pocket to turn it on, and she touched my arm. "Not a good idea," she said. "Some of this may be cla.s.sified."

"Oh," I said. "Thanks." And dropped it back into my pocket, thumbing it on anyway as I did so. I don't think she saw.

The unhappy man began banging his bell again. "I think we can begin now. For those of you who don't know, I'm Dr. Olmstead, Dr. Edward K. Olmstead, and I am the acting director of the Extraterrestrial Studies Group of the National Science Center here in Denver. I'd like to take this opportunity to welcome all of you to this special session of the Continuing International Conference on Extraterrestrial Affairs.

"I am required by the rules of this conference to remind you that much of the material that we will be presenting here is generally cla.s.sified on a need-to-know basis. While that includes all of our registered attendees and their respective staffs, we still want to stress that the material is for your use only and should be treated as confidential. We are not yet prepared to release some of this information to the general public. The reasons for this will be discussed in tomorrow's session on culture shock. Your cooperation is greatly appreciated. Thank you.

"This special Sat.u.r.day session is being held for the convenience of those delegates who will not be here for the full conference schedule. As always, this session is going out live on channel two. If you need more information on any specific subject, that access is available through the project network, of course. Please feel free to tap in. If you don't already have a clearance number, check with the desk.

"As you can see by your schedules, we're going to try to present all of the scientific material in the first two and a half hours, and follow up with the more important questions of contact and containment procedures this afternoon-after a reasonable break for lunch, of course. As I'm sure most of you have already discovered, the hotel here has an excellent buffet. Tomorrow we will spend the morning session on the cultural and psychological questions, and the afternoon meeting will deal with the economic sphere. We do apologize for presuming on so much of your time, and we thank you in advance for your cooperation. This is, of course, a working weekend, so at this time I'd like to turn the microphone over to our conference chairperson, Dr. Moyra Zymph."

There was a spattering of polite applause as Dr. Zymph came up to the dais. She was a stout woman, slightly disheveled, and she moved like a truck driver. When she spoke, it was with a gravelly, I-mean-business voice. "All right, let's get to it." She slapped her clipboard down onto the podium. "I know that most of you are more interested in finding out the answers than in listening to the questions. Unfortunately, all we have right now are questions. We have lots of questions . . ." She paused for effect . . . "and a few educated guesses, which I will share with you.

"I want you to think of a jigsaw puzzle-with most of the pieces missing and no picture on the cover of the box to guide you. Now think of a warehouse full of similar incomplete jigsaw puzzles. Now mix them all up. Now find someone who's never seen a jigsaw puzzle before in his life, and put him in the middle of this pile of mixed-up pieces and ask him to figure out what's going on here. At the point he realizes what a jigsaw puzzle is, he's won the game. He's solved the hardest part of the problem. "I want you to hold that picture in mind, because that's what we're up to here. We've got a warehouse full of pieces. We know what individual pieces look like, but we don't know what the pictures look like-we do know for sure that this is a warehouse full of incomplete puzzles. We've solved the hard part. And we'll tell you about that.

"Now, some of you are not going to like what you hear. You are especially not going to like the implications. Some of you may be so disturbed by the material presented that you'll want to question its validity. You'll want to dismiss our conclusions because you can't accept the facts. Please do not make that mistake.

"I want you to know that it's all right to be uncomfortable with the material. We certainly are ... and we've been living with it for a while. Just don't use that discomfort as an excuse to hide from the urgency of the situation." She paused long enough to let that sink in, looking around the auditorium as if daring anyone to object.

No one did. Not yet. Dr. Zymph nodded and continued. "Good. So what we're going to do here today is show you some of the pieces that we are certain about and then go from there to the larger pattern. I will not be showing you all of our puzzle pieces-we don't have the time-but I will be showing you those items which you most need to know about."

She switched her clipboard on and began referring to it. "First off, we can tell you this. The Earth, this planet that we live on, is experiencing an ecological infestation. The source of the infestation is presumed to be extraterrestrial." She touched a hidden control on the podium and the screen behind her came back to life, showing two views of the Earth, front and back. There were red splotches blinking across the larger land areas. It looked like a case of measles. She continued: "The infestation has appeared on all five major continents: Asia, Africa, both of the Americas and to a lesser extent-although we don't know why yetEurope. We have not yet confirmed any signs of infestation in Australia or Antarctica. So far, the evidence suggests that it is generally limited to the temperate zones of the planet, the same areas in which the bulk of our human population is established. That is, the remaining human population." She stopped and looked out at the room. "The-uh, population crisis will be discussed at tomorrow's session. I urge all of you to be there. We do have some specific recommendations, but they have to be implemented immediately. And I want to point out that our primary concern is not just saving our human resources, but putting them to work in ways that contribute to the larger effort." She looked uncomfortable. She bent back to the security of the notes on her clipboard.

"The infestation has manifested itself in several distinct forms that we are aware of-and probably quite a few more that we have not yet discovered." She stopped, touched a control, looked behind her to see that the screen was showing the appropriate slide-some kind of red sludge floating on a lake-and continued. "While most of the attention has been focused on the more, ah, dramatic aspects of this infestation, I want to make you aware that that there is considerable ecological impact in other areas as well. We are experiencing events in the microbial and botanical spheres, for instance, that are every bit as serious, though perhaps not as noticeable.

"I'm going to give you only a few examples to demonstrate the scope of the problem. Please be a.s.sured that it is far worse than these examples suggest. This first one is a kind of algae. It breeds fast, it floats on the surface of the ocean and it's moderately toxic. It tends to occur primarily in the offsh.o.r.e regions, but it can also be found on still lakes and backwaters. Once it establishes itself, it tends to choke out most other plant life. It does not use chlorophyll for photosynthesis, which explains its red to red-purple color." Behind her, the screen showed muddy crimson breakers crashing on a long stretch of sh.o.r.e. The pink sand was stained with dirty streaks that looked like clotted blood.

"As I said, it is moderately toxic, and I want to take a moment to expand on this. The sludge exudes a particularly nasty set of byproducts, including some interesting long-chain molecules that seem intended for use by the next creature in line in the ecology; but whatever that creature is, it hasn't manifested itself yet. And I don't know whether to be thankful or not.

"Sludge-infested water usually feels oily-and the oil is particularly difficult to clean off. But if you do get the oil on you, it's essential to get it off as quickly as you can, because it very effectively clogs human pores and reduces the skin's ability to breathe. For the record, it also smells bad-so at least you have that much warning.

"If you are unlucky enough to swallow sludge-infested water, you will definitely regret it. You'll experience nausea, diarrhea, vomiting and fever. If you're strong, you'll survive. If not, you won't.

"Now, I want you to think about the fish and the plants in that same water-unlike you, they can't get out to go lie down for a while. Prolonged exposure to the sludge is always fatal to them. The smaller the creature, the quicker it dies.

"Wherever the red sludge appears, the plankton disappearsfollowed by the fish that feed on the plankton and the predators that feed on them, all the way up the food chain. The red sludge turns ocean into desert. This is going to have a disastrous effect on the global food chain if it is not controlled. If the seas die, we die. And already the red sludge has infected three-tenths of a percent of the world's farmable waters, and that figure is climbing at an alarming rate. Now, I know that three-tenths of a percent doesn't sound like a lot, but when you consider that two-thirds of the Earth is covered by water, then you have to realize that we are already talking about several hundred thousand square miles-and it may be in the millions already; we don't know for sure. But you can extrapolate from that." The screen showed the map of the world again. There were red streaks off the coast of China, California, Brazil and parts of Africa. "These are the areas of primary infestation," she said. "At the present rate of spread, within two to five years most of the world's richest sea farms will be lost.

"I do wish to alarm you about this-because this may be the single most threatening aspect of the infestation. So far, the sludge has resisted most of our attempts to control it. It does not seem to be temperature sensitive, and it can survive a wide range of water conditions. We've had some success at inhibiting the growth of the sludge with tailored bacteria, but it is a limited success. To date, our best results have been obtained by pouring crude oil on the water and setting it on fire. I'm sure I don't have to say much about the unacceptability of that solution."

She stopped to take a drink of water, checked her notes, then brought up another series of pictures on the screen-spme kind of insect-looking bug; but it stood on two legs. Its front four legs were very short, they looked atrophied, except that each terminated in a very strong-looking claw. The gra.s.shopper in its mandibles established a sense of scale. The bug was the size of a sparrow. "This is not an insect," Dr. Zymph said. "Do not fall into the trap of thinking that it is an insect, because to do that is to wear blinders to the possibilities that the creature has some very un-insectlike capabilities."

The next picture showed the creature standing-almost lurking-in a dark corner. It stood erect, and its long black sh.e.l.l-casing enveloped it like a cape. The shape of its head as well as its posture made me think of Jack the Ripper. "We call this fellow the nightwalker," Dr. Zymph said. "He's a comparatively recent discovery, so we can't tell you too much about him. He eats most kinds of terrestrial insects, and is not averse to the occasional mouse, bird or frog. This is a small one. We've found them as big as twenty centimeters. We hope that's as big as they get. We're not sure. They are not poisonous, but the bite is painful. An interesting thing about that bite-most predatory insects liquify their food to eat it; this fellow is large enough, he doesn't have to bother. He uses his mandibles like teeth. We believe that his digestion is something like a bird's in that he may have to swallow small pebbles to help grind the food in his stomach. This is a good place to note that he is a serious compet.i.tor for the birds' place in the ecology. He has a voracious appet.i.te and will undoubtedly provide some very powerful compet.i.tion to all of our smaller predators."

Another set of pictures-this time, it was a pink puffball thing. "We're still not sure if this one is plant or animal. We call it the cotton candy bug. It's as light as a dandelion, and it's as easily spread. It is nontoxic, it is edible and, as far as we have been able to determine, it does not appear to endanger its surroundings. What that means is that we still haven't determined what kind of a danger it is-and I'll touch on that point in a minute too.

"First, I want to show you this cute little fellow-" There was polite laughter as the slide came up on the screen. "We call him the pipe cleaner bug, because he looks like he's made out of pipe cleaners. Again, do not be misled by the fact that he looks like an insect. That's just the ecological niche he lives in. He does not have a segmented body, and his exoskeleton is covered with a thick skin and that soft white fur that you see. That fur is actually a very sensitive olfactory organ. The creature smells the air with his whole body. Now note the bunny feet: those pads are also sensory organs, even more sensitive. He's not just standing on that leaf, he's tasting it as well. The creature's eyes are on the tip of those two antennae, and they are regenerative. This fellow eats the cotton candy bugs; he is eaten by the nightwalker. I can't tell you much more than that. We know nothing about his breeding habits. We can tell you that he moves very fast and can eat twice his own weight in leaves every day. We expect to be seeing a lot more of him next summer. Or even sooner."

The next picture was of a scarlet-leafed field of ivy. "We call this one red kudzu for obvious reasons. The leaves are bright red and veined with white. It likes marshes and shallow water, and it breeds like madness, advancing at the rate of two meters per week. So far, we've only found it in the Louisiana bayous, but we expect to see it spread throughout the entire Gulf Coast if it isn't controlled."

The audience was beginning to get uneasy. There were too many of these creatures.

"Now this one-looks like an Earth millipede, except for the hump across its, ah, shoulders-we're not even sure it belongs here in this catalog. There's some evidence to suggest that it may be a terrestrial creature; we know that there were several of them under study at the African Ecology Center in Nairobi more than twenty years ago, but they were lost in the firestorm that destroyed the city. These creatures are omnivorous, and they're capable of short bursts of speed across open territory. We think they serve primarily as scavengers in the Chtorran ecology. We've not seen a lot of them. Now, this next one-"

Huh? Was that it? She hadn't said anything about the millipedes! And why did the Chtorrans have a corral full of them? "-looks like the anopheles mosquito, but again, please do not be fooled by the resemblance. It's only superficial. There are significant internal differences. We call this a stingfly. It feeds on blood-human blood is fine, but it's just as happy with cats, dogs, cattle, horses-anything else it can find. It's not choosy, and for that reason we suspect it to be a primary vector for disease. . . ." She had to pause here; there was an excited hubbub in the audience. After a moment, she raised her voice and continued over it. "We suspect it; we are not yet certain. There are too many questions still unanswered. But"-and she leaned forward on the podium now, steepling her hands in front of her"we are looking at it as the most likely mechanism for introducing the plagues into the human population." She was well aware of the ramifications of that statement. And so was her audience.

She said loudly, "I want you to get this-it's still only a theory! We do know that two of the plagues appeared in more than one form-like the bubonic and pneumonic forms of the Black Death. And most of them can be spread by a sneeze, or by touching a contaminated cup or blanket. So what we're looking at here-this stingfly-is not a primary vector, merely a method of introduction. If that. But this does lead right into the next point ... the plagues themselves.

"We are now operating on the theory that the seven major infections and nine minor ones that have decimated the human species must also be considered as part of the overall pattern of ecological infestation. I want you to know that we came to this realization slowly. When you look at the overlapping patterns of disease and infestation, the relationship is obvious; but even as recently as several months ago, when most of us were still reeling from the initial impact of the disaster, we simply did not have enough reliable information to establish the correlation.

"Um, I'm not going to go into the political and psychological arenas here, but I do want to point out the reasons why conclusive identification of the diseases as extraterrestrial was delayed until the early part of this year. Convincing our respective governments -and I do not mean this as criticism-that there was a very real presence on this planet was, under the circ.u.mstances, the hardest part of the job. We had very little hard evidence, and it was difficult to have our voices heard during the, ah, worst of the hysteria. We cannot afford to let confusion like that happen again!" She stopped herself. Apparently, she realized she was getting angry. She took a sip of water and looked at her notes. She seemed to do that a lot when she was dealing with an uncomfortable subject. Was that for herself or her audience? I wasn't sure. When she was ready, she looked out over the room again.

"I want to say something here. I want to deal with certain avenues of speculation. During the early days of the plagues, there were a number of accusations-on all sides-that they were a weapon of war. At that time, it was a.s.sumed that there was a human agency responsible. We know that not to be the case now. The devastation has touched all of us equally, and no nation on this planet has profited by the plagues. And, of course, now the biological evidence is also falling into place-so we must put our distrust and our suspicion behind us. Now! The situation is too urgent for us to have our energies divided."

She placed her hands on both sides of the podium. She looked around the room, as if she were looking into the eyes of each and every one of us in the auditorium. She said, "The accusation that the plagues are a weapon of war is not entirely accurate-because it's too shortsighted! They are actually a tool of ecological engineering. We as humans may be somewhat biased about the application of such a devastating tool, but as scientists we cannot help but admire the skill with which this particular tool was applied. Almost eighty percent of the members of the dominant species of this planet have been excised as neatly as a surgeon cutting out a cancer with a laser. If that is how they see us, then they should have no problem with the subsequent applications of-continuing with the same metaphor---chemotherapy. We shall see. But if that was their goal, then they have accomplished most of their objective in a very short time. Less than two years." She stopped and wiped her forehead with her handkerchief. She took another drink of water.

When she spoke again, her voice was lower, slower and steadier. The gravelly quality was muted somehow, and she seemed suddenly very serious. "We have been speaking of this as an ecological infestation, because we can't prove that it's anything more. We have specifically not called this an invasion, because we have not been able to find an invading force. We have no evidence of extraterrestrial landings, no sightings of ships, no evidence of advanced technology of any kind. If we are being invaded, then where are the invaders?

"For a while, we suspected that the large purple and red creatures that we have been calling Chtorrans were our alien visitors, but this theory is rapidly falling into disrepute, because we have not been able to prove that these creatures even have the potential for intelligence-let alone the capabilities necessary to mount such an invasion across the vast distances of s.p.a.ce. We are a.s.suming, of course, that this ecological infestation has as its source a planet in another star system-it could not possibly have originated on any of the planets in our own solar system. I refer you to Dr. Swale's a.n.a.lysis for the reasons why we have come to that position. So the question remains: where are the invaders?

"I'm actually going to answer that-in a way. But it's a circuitous route. You'll have to bear with me a bit, because in order to find out who the culprit is, we have to take a good long look at the evidence.

"When we look at the overall pattern-the stingflies, the nightwalkers, the red kudzu, the sea sludge, the bacteria that caused the plagues, even the, ah, Chtorrans themselves-we find that there is a p.r.o.nounced tendency toward voraciousness, as if all of these life forms have evolved in a much more compet.i.tive ecology, not only surviving, but succeeding in that environment. Here on Earth, without their natural predators-all the checks and balances of a stable ecology-these life forms cannot help but run wild. We're seeing it happen all over the planet.

"We expect to find that none of these creatures are harmless to the Terran ecology-especially not the ones that look harmless. They're the ones that represent the biggest danger, because they're the ones we're most likely to underestimate. We have one hundred and fifty-four new species identified, and there are probably a lot more that we haven't yet discovered. And that's because we don't have the people. For all practical purposes, most of the world's ecological maintenance agencies have ceased to exist. And that leaves us particularly vulnerable to this kind of ecological infestation-twice over. Once because we don't know all of what's happening out there, and twice because even where we do have monitors in the field, we do not have the resources to respond. We need to rebuild those agencies-without delay! If we mobilize now, there is still the chance that we can create a strong response to the threat. If not, then the pressure on our ecology of those hundred and fifty-four various and voracious new species will surely shatter what remains of life as we know it on this planet.

"It is this simple: our ecology is under attack by a far more successful ecology. The home planet may be half a billion-I said billion-years older than the Earth-with all the corresponding advantages of extended evolution that implies for the member species of that planet's ecology. The implied age of the ecology and its host planet may also be a clue to why this infestation is occurring at all. The host planet may be wearing out. Or its sun may be going cold. What we are seeing may very well be an attempt by an intelligent species to-outlive the death of its home system.

"And-if we are correct about the age of the Chtorran ecology, that is also why we will not be able to use terrestrial microorganisms against the Chtorran life forms. If the Chtorran life forms that we have seen are the products of an extra umpteen million years of evolution, then that implies that they would also have the c.u.mulative immunities against every mutation of every germ that has evolved on their home planet. And that suggests that they would therefore have a greater spectrum of resistance to unknown microorganisms. Our germs are going to be no threat to them, because to them, our ecology is simpler-much simpler. We are the great reptiles looking at the appearance of gra.s.s and blossoming flowers and therapsids in our ecology and wondering what the h.e.l.l is happening to our world. We have no natural defenses here."

She leaned out across the podium as if to look into the face of every one of us in that auditorium. "If we accept this hypothesis -and I do not see how we can avoid it-then the motive of the initiating agency is no longer in question. There is only one possible interpretation of the situation: we are at war! A war unlike anything ever experienced or even conceived in the history of this planet!" She stopped herself, as if she were embarra.s.sed at her own intensity. She covered it with a drink of water, just a sip, then continued. "The problem is that we have no evidence of the agency behind this invasion. It has to be there, but where is it? Again we come back to the question: where are the real Chtorrans?" Dr. Zymph let the question hang there in the air for a moment. She looked over her notes and rubbed the bridge of her thick nose between thumb and forefinger.

She looked up again, and when she spoke, it was like a burst of gunfire. "Actually, we might be asking the wrong question. We have to look at the situation from an invader's point of view. I refer you now to the Skotak-Alderson studies on how to colonize a planet. In those papers, of course, the authors were talking about Venus and Mars, but the general principles they laid down are extensible to any world.

"Briefly, Skotak and Alderson broke the colonization process down into sections. Part I is Terraforming and Phase I involves producing an atmosphere that Terran organisms can survive in. Phase II begins with the introduction of selected life forms to create a favorable protoecology on the world to be colonized.

"Now, applying that to our own situation, obviously some intelligence somewhere is working its own Phase II here on Earth. They are Chtorraforming the planet, if you will.

"Just as we would need to establish gra.s.slands to feed our cattle, cornfields to feed our chickens, forests to provide our paper and lumber and plastics, bees to pollinate the blossoms of our plants so we can have fruits and vegetables, so must our unknown Chtorran planners need to establish the equivalent support species necessary to the survival of their civilization. That is precisely what is happening now. And will continue to happen.

"Based on a weighted Skotak-Alderson simulation, the infestation of the Earth will occur in three, perhaps four, distinct stages. Each stage will see a specific level of species support established before the next level appears. In other words, they won't bring in the Chtorran equivalent of coyotes until the Chtorran rabbits are fat, and they won't bring in the Chtorran rabbits until the Chtorran pastures are green--0r in this case, purple-and they won't plant the pastures until the Chtorran earthworms have softened the ground. That puts us at a disadvantage, because we'll be seeing each species out of context, not knowing where each one fits in the larger pattern. It'll be as difficult as trying to extrapolate the rest of the symphony, when all you have is the sheet music for the tympanist and the third trombone.

"That's why we can't give you the hard answers yet. What facts we do have are still unconnected. We can only give you the larger pattern that all the facts point to. This infestation of the Earth is their way of clearing the land. It's the easiest way to deal with the local residents-clear them out before you move in. We're supposed to be long gone before the new tenants arrive. If you'll pardon an unpleasant metaphor, what we are experiencing is the Chtorran version of a slum clearance. A neighborhood improvement project-"

She pointed to the screen behind her. It lit up with slides of the nightwalker, the millipedes, the sea sludge, the red kudzu, the stingfly, the puffball creature, the pipe cleaner bug and a whole bunch of other things I didn't recognize. Dr. Zymph said, "-and these are the shock troops- the advance men for a highly compet.i.tive ecology; these are the bugs and beasties that are intended to soften up this planet for the rest of the ecology to follow. Let me say it again: the present infestation is only the first wave of a much larger and meaner infestation still to come. What comes next are the creatures that eat these!"

She bent to her notes for a moment, frowning, then looked up at us again. Her expression was grim. "Don't be misled by those who would minimize the situation. We are not going to find any easy controls for this or later infestations. We do not have the necessary compet.i.tion on this planet. We human beings may not even be compet.i.tive enough, ruthless and vicious enough, to muster the necessary effort. I hope I'm wrong. But I don't think I am." She paused a moment to let that sink in.

"We must recognize from the very beginning that our natural defenses are not going to work. Our only possible countermeasures will be developed by finding the weaknesses within the Chtorran ecology. We must discover the interrelationships of these creatures and sabotage them in any way we can. We must use this invading ecology against itself! We must start today! It will not be an easy task! It will require a ma.s.sive mobilizationthe complete and total mobilization of every human being on this planet! And we must begin it immediately!"

She stopped to wipe her forehead. She was beginning to show the strain of what must have been for her a very difficult task. I was beginning to suspect something from the audience reactions around me. These delegates hadn't come here to be frightened out of their wits, but that was exactly what she was trying to do. From their continual disturbed murmuring, I guessed that they had come with the idea that they were going to be rea.s.sured that everything was under control-we just need an increase in next year's appropriations, no problem, and then we can all go home, back to our newly claimed wealth. Only it wasn't working out that way.

Dr. Zymph was talking about the end of the world. And I could see the hostility on some of the faces of her listeners.

She was saying, "-I will not try to soften this for you, because I do not think the dangers can be understated. We are facing extinction.

"We are not being invaded," she said. "Not yet.

"But-we are going to be invaded.

"How soon it will happen, we don't know. How long this phase will last, we don't know. What kind of creatures have initiated it, we don't know. What kind of creatures will appear next, we don't know. But I promise you-we will find out. If we live.

"It is inevitable. We are going to be invaded. By something. By the next level of this ecology. By the life forms that feed on these. And whatever comes, whatever form it takes, will be umpteen times more compet.i.tive-meaner, nastier and more vicious -than the things we're seeing now. What you see up there"and she pointed toward the screen again, her arm stretched up and back, her finger stabbing like a pistol at the last of her slides, the gaping maw of a full-sized crimson Chtorran-"is just a candle before the firestorm!"

And with that she was through. She did not say, "Thank you," but it was clear that she was finished. She switched off her clipboard and strode from the stage.

There was no applause.

TWENTY-ONE.

DR. ZYMPH'S remarks had not gone over well. You could feel the resentment. The audience boiled out of the auditorium like a nest of hornets. Their voices rising shrilly, they cl.u.s.tered into angry knots. Small arguments were breaking out all over, some erupting into shouting matches.

"-outrageous!" fumed one little man, shoving rudely past me. He was dark-skinned, he wore an expensive suit and he had a thick Middle-East accent. "Lies and propaganda! Next we're going to be told that the only answer is a military one! But my government isn't going to buy their horror stories! They're using this as an excuse for their own rearmament-" The rest was lost in the hubbub.

"I'm telling you she did not!" A tall, bald man with gla.s.ses was surrounded by a score of other scientists. "If anything, this was the toned-down version! If there's been any misstatement in the facts, it's been on the side of caution!"