MYCOGEN-... A sector of ancient Trantor buried in the past of its own legends. Mycogen made little impact on the planet. Self-satisfied and self-separated to a degree...

Encyclopedia Galactica

31.

When Seldon woke, he found a new face looking at him solemnly. For a moment he frowned owlishly and then he said, "Hummin?"

Hummin smiled very slightly. "You remember me, then?"

"It was only for a day, nearly two months ago, but I remember. You were not arrested, then, or in any way-"

"As you see, I am here, quite safe and whole, but-and he glanced at Dors, who stood to one side-"it was not very easy for me to come here."

Seldon said, "I'm glad to see you.-Do you mind, by the way?" He jerked his thumb in the direction of the bathroom.

Hummin said, "Take your time. Have breakfast."

Hummin didn't join him at breakfast. Neither did Dors. Nor did they speak. Hummin scanned a book-film with an attitude of easy absorption. Dors inspected her nails critically and then, taking out a microcomputer, began making notes with a stylus.

Seldon watched them thoughtfully and did not try to start a conversation. The silence now might be in response to some Trantorian reserve customary at a sickbed. To be sure, he now felt perfectly normal, but perhaps they did not realize that. It was only when he was done with his last morsel and with the final drop of milk (which he was obviously getting used to, for it no longer tasted odd) that Hummin spoke.

He said, "How are you, Seldon?"

"Perfectly well, Hummin. Sufficiently well, certainly, for me to be up and about."

"I'm glad to hear it," said Hummin dryly. "Dors Venabili was much to blame in allowing this to happen."

Seldon frowned. "No. I insisted on going Upperside."

"I'm sure, but she should, at all costs, have gone with you."

"I told her I didn't want her to go with me."

Dors said, "That's not so, Hari. Don't defend me with gallant lies."

Seldon said angrily, "But don't forget that Dors also came Upperside after me, against strong resistance, and undoubtedly saved my life. That's not bending the truth at all. Have you added that to your evaluation, Hummin?"

Dors interrupted again, obviously embarrassed. "Please, Hari. Chetter Hummin is perfectly correct in feeling that I should either have kept you from going Upperside or have gone up with you. As for my subsequent actions, he has praised them."

"Nevertheless," said Hummin, "that is past and we can let it go. Let us talk about what happened Upperside, Seldon."

Seldon looked about and said guardedly, "Is it safe to do so?"

Hummin smiled slightly. "Dors has placed this room in a Distortion Field. I can be pretty sure that no Imperial agent at the University-if there is one-has the expense to penetrate it. You are a suspicious person, Seldon."

"Not by nature," said Seldon. "Listening to you in the park and afterward- You are a persuasive person, Hummin. By the time you were through, I was ready to fear that Eto Demerzel was lurking in every shadow."

"I sometimes think he might be," said Hummin gravely.

"If he was," said Seldon, "I wouldn't know it was he. What does he look like?"

"That scarcely matters. You wouldn't see him unless he wanted you to and by then it would all be over, I imagine-which is what we must prevent. Let's talk about that jet-down you saw."

Seldon said, "As I told you, Hummin, you filled me with fears of Demerzel. As soon as I saw the jet-down, I assumed he was after me, that I had foolishly stepped outside the protection of Streeling University by going Upperside, that I had been lured up there for the specific purpose of being picked up without difficulty."

Dors said, "On the other hand, Leggen-"

Seldon said quickly, "Was he here last night?"

"Yes, don't you remember?"

"Vaguely. I was dead tired. It's all a blur in my memory."

"Well, when he was here last night, Leggen said that the jet-down was merely a meteorological vessel from another station. Perfectly ordinary. Perfectly harmless."

"What?" Seldon was taken aback. "I don't believe that."

Hummin said, "Now the question is: Why don't you believe that? Was there anything about the jet-down that made you think it was dangerous? Something specific, that is, and not just a pervasive suspicion placed in your head by me."

Seldon thought back, biting his lower lip. He said, "Its actions. It seemed to push its forepart below the cloud deck, as though it were looking for something, then it would appear in another spot just the same way, then in another spot, and so on. It seemed to be searching Upperside methodically, section by section, and homing in on me."

Hummin said, "Perhaps you were personifying, Seldon. You may have been treating the jet-down as though it was a strange animal looking for you. It wasn't, of course. It was simply a jet-down and if it was a meteorological vessel, its actions were perfectly normal... and harmless."

Seldon said, "It didn't seem that way to me."

Hummin said, "I'm sure it didn't, but we don't actually know anything. Your conviction that you were in danger is simply an assumption. Leggen's decision that it was a meteorological vessel is also only an assumption."

Seldon said stubbornly, "I can't believe that it was an entirely innocent event."

"Well then," said Hummin, "suppose we assume the worst-that the vessel was looking for you. How would whoever sent that vessel know you would be there to seek?"

Dors interjected, "I asked Dr. Leggen if he had, in his report of the forthcoming meteorological work, included the information that Hari would be with the group. There was no reason he should in the ordinary course of events and he denied that he had, with considerable surprise at the question. I believed him."

Hummin said thoughtfully, "Don't believe him too readily. Wouldn't he deny it, in any case? Now ask yourself why he allowed Seldon to come along in the first place. We know he objected initially, but he did relent, without much fight. And that, to me, seems rather out of character for Leggen."

Dors frowned and said, "I suppose that does make it a bit more likely that he did arrange the entire affair. Perhaps he permitted Hari's company only in order to put him in the position of being taken. He might have received orders to that effect. We might further argue that he encouraged his young intern, Clowzia, to engage Hari's attention and draw him away from the group, isolating him. That would account for Leggen's odd lack of concern over Hari's absence when it came time to go below. He would insist that Hari had left earlier, something he would have laid the groundwork for, since he had carefully showed him how to go down by himself. It would also account for his reluctance to go back up in search of him, since he would not want to waste time looking for someone he assumed would not be found."

Hummin, who had listened carefully, said, "You make an interesting case against him, but let's not accept that too readily either. After all, he did come Upperside with you in the end."

"Because footsteps had been detected. The Chief Seismologist had [been] witness to that."

"Well, did Leggen show shock and surprise when Seldon was found? I mean, beyond that of finding someone who had been brought into extreme peril through Leggen's own negligence. Did he act as though Seldon wasn't supposed to be there? Did he behave as though he were asking himself: How is it they didn't pick him up?"

Dors thought carefully, then said, "He was obviously shocked by the sight of Hari lying there, but I couldn't possibly tell if there was anything to his feelings beyond the very natural horror of the situation."

"No, I suppose you couldn't."

But now Seldon, who had been looking from one to the other as they spoke and who had been listening intently, said, "I don't think it was Leggen."

Hummin transferred his attention to Seldon. "Why do you say that?"

"For one thing, as you noted, he was clearly unwilling to have me come along. It took a whole day of argument and I think he agreed only because he had the impression that I was a clever mathematician who could help him out with meteorological theory. I was anxious to go up there and, if he had been under orders to see to it that I was taken Upperside, there would have been no need to be so reluctant about it."

"Is it reasonable to suppose he wanted you only for your mathematics? Did he discuss the mathematics with you? Did he make an attempt to explain his theory to you?"

"No," said Seldon, "he didn't. He did say something about going into it later on, though. The trouble was, he was totally involved with his instruments. I gathered he had expected sunshine that hadn't showed up and he was counting on his instruments having been at fault, but they were apparently working perfectly, which frustrated him. I think this was an unexpected development that both soured his temper and turned his attention away from me. As for Clowzia, the young woman who preoccupied me for a few minutes, I do not get the feeling, as I look back on it, that she deliberately led me away from the scene. The initiative was mine. I was curious about the vegetation on Upperside and it was I who drew her away, rather than vice versa. Far from Leggen encouraging her action, he called her back while I was still in sight and I moved farther away and out of sight entirely on my own."

"And yet," said Hummin, who seemed intent on objecting to every suggestion that was made, "if that ship was looking for you, those on board must have known you'd be there. How would they know-if not from Leggett?"

"The man I suspect," said Seldon, "is a young psychologist named Lisung Randa"

"Randa?" said Dors. "I can't believe that. I know him. He simply would not be working for the Emperor. He's anti-Imperialist to the core."

"He might pretend to be," said Seldon. "In fact, he would have to be openly, violently, and extremely anti-Imperialist if he was trying to mask the fact that he is an Imperial agent."

"But that's exactly what he's not like," said Dors. "He is not violent and extreme in anything. He's quiet and good-natured and his views are always expressed mildly, almost timidly. I'm convinced they're genuine."

"And yet, Dors," said Seldon earnestly, "it was he who first told me of the meteorological project, it was he who urged me to go Upperside, and it was he who persuaded Leggen to allow me to join him, rather exaggerating my mathematical prowess in the process. One must wonder why he was so anxious to get me up there, why he should labor so hard."

"For your good, perhaps. He was interested in you, Hari, and must have thought that meteorology might have been useful in psychohistory. Isn't that possible?"

Hummin said quietly, "Let's consider another point. There was a considerable lapse of time between the moment when Randa told you about the meteorology project and the moment you actually went Upperside. If Randa is innocent of anything underhanded, he would have no particular reason to keep quiet about it. If he is a friendly and gregarious person-"

"He is," said Dors.

"-then he might very likely tell a number of friends about it. In that case, we couldn't really tell who the informer might be. In fact, just to make another point, suppose Randa is anti-Imperialist. That would not necessarily mean he is not an agent. We would have to ask: Whom is he an agent for? On whose behalf does he work?"

Seldon was astonished. "Who else is there to work for but the Empire? Who else but Demerzel?"

Hummin raised his hand. "You are far from understanding the whole complexity of Trantorian politics, Seldon." He turned toward Dors. "Tell me again: Which were the four sectors that Dr. Leggen named as likely sources for a meteorological vessel?"

"Hestelonia, Wye, Ziggoreth, and North Damiano."

"And you did not ask the question in any leading way? You didn't ask if a particular sector might be the source?"

"No, definitely not. I simply asked if he could speculate as to the source of the jet-down."

"And you"-Hummin turned to Seldon "may perhaps have seen some marking, some insigne, on the jet-down?"

Seldon wanted to retort heatedly that the vessel could hardly be seen through the clouds, that it emerged only briefly, that he himself was not looking for markings, but only for escape-but he held back. Surely, Hummin knew all that. Instead, he said simply, "I'm afraid not."

Dors said, "If the jet-down was on a kidnapping mission, might not the insigne have been masked?"

"That is the rational assumption," said Hummin, "and it tray well have been, but in this Galaxy rationality does not always triumph. However, since Seldon seems to have taken no note of any details concerning the vessel, we can only speculate. What I'm thinking is: Wye."

"Why?" echoed Seldon. "I presume they wanted to take me because whoever was on the ship wanted me for my knowledge of psychohistory."

"No, no." Hummin lifted his right forefinger as if lecturing a young student. "W-y-e. It is the name of a sector on Trantor. A very special sector. It has been ruled by a line of Mayors for some three thousand years. It has been a continuous line, a single dynasty. There was a time, some five-hundred years ago, when two Emperors and an Empress of the House of Wye sat on the Imperial throne. It was a comparatively short period and none of the Wye rulers were particularly distinguished or successful, but the Mayors of Wye have never forgotten this Imperial past.

"They have not been actively disloyal to the ruling houses that have succeeded them, but neither have they been known to volunteer much on behalf of those houses. During the occasional periods of civil war, they maintained a kind of neutrality, making moves that seemed best calculated to prolong the civil war and make it seem necessary to turn to Wye as a compromise solution. That never worked out, but they never stopped trying either.

"The present Mayor of Wye is particularly capable. He is old now, but his ambition hasn't cooled. If anything happens to Cleon-even a natural death-the Mayor will have a chance at the succession over Cleon's own too-young son. The Galactic public will always be a little more partial toward a claimant with an Imperial past.

"Therefore, if the Mayor of Wye has heard of you, you might serve as a useful scientific prophet on behalf of his house. There would be a traditional motive for Wye to try to arrange some convenient end for Cleon, use you to predict the inevitable succession of Wye and the coming of peace and prosperity for a thousand years after. Of course, once the Mayor of Wye is on the throne and has no further use for you, you might well follow Cleon to the grave."

Seldon broke the grim silence that followed by saying, "But we don't know that it is this Mayor of Wye who is after me."

"No, we don't. Or that anyone at all is after you, at the moment. The jet-down might, after all, have been an ordinary meteorological testing vessel as Leggen has suggested. Still, as the news concerning psychohistory and its potential spreads-and it surely must-more and more of the powerful and semi-powerful on Trantor or, for that matter, elsewhere will want to make use of your services."

"What, then," said Dors, "shall we do?"

"That is the question, indeed." Hummin ruminated for a while, then said, "Perhaps it was a mistake to come here. For a professor, it is all too likely that the hiding place chosen would be a University. Streeling is one of many, but it is among the largest and most free, so it wouldn't be long before tendrils from here and there would begin feeling their soft, blind way toward this place. I think that as soon as possible-today, perhaps-Seldon should be moved to another and better hiding place. But-"

"But?" said Seldon.

"But I don't know where."

Seldon said, "Call up a gazeteer on the computer screen and choose a place at random."

"Certainly not," said Hummin. "If we do that, we are as likely to find a place that is less secure than average, as one that is more secure. No, this must be reasoned out.-Somehow."

32.

The three remained huddled in Seldon's quarters till past lunch. During that time, Hari and Dors spoke occasionally and quietly on indifferent subjects, but Hummin maintained an almost complete silence. He sat upright, ate little, and his grave countenance (which, Seldon thought, made him look older than his years) remained quiet and withdrawn.

Seldon imagined him to be reviewing the immense geography of Trantor in his mind, searching for a corner that would be ideal. Surely, it couldn't be easy. Seldon's own Helicon was somewhat larger by a percent or two than Trantor was and had a smaller ocean. The Heliconian land surface was perhaps 10 percent larger than the Trantorian. But Helicon was sparsely populated, its surface only sprinkled with scattered cities; Trantor was all city. Where Helicon was divided into twenty administrative sectors; Trantor had over eight hundred and every one of those hundreds was itself a complex of subdivisions.

Finally Seldon said in some despair, "Perhaps it might be best, Hummin, to choose which candidate for my supposed abilities is most nearly benign, hand me over to that one, and count on him to defend me against the rest."

Hummin looked up and said in utmost seriousness, "That is not necessary. I know the candidate who is most nearly benign and he already has you."

Seldon smiled. "Do you place yourself on the same level with the Mayor of Wye and the Emperor of all the Galaxy?"

"In point of view of position, no. But as far as the desire to control you is concerned, I rival them. They, however, and anyone else I can think of want you in order to strengthen their own wealth and power, while I have no ambitions at all, except for the good of the Galaxy."

"I suspect," said Seldon dryly, "that each of your competitors-if asked-would insist that he too was thinking only of the good of the Galaxy."

"I am sure they would," said Hummin, "but so far, the only one of my competitors, as you call them, whom you have met is the Emperor and he was interested in having you advance fictionalized predictions that might stabilize his dynasty. I do not ask you for anything like that. I ask only that you perfect your psychohistorical technique so that mathematically valid predictions, even if only statistical in nature, can be made."

"True. So far, at least," said Seldon with a half-smile.

"Therefore, I might as well ask: How are you coming along with that task? Any progress?"

Seldon was uncertain whether to laugh or cage. After a pause, he did neither, but managed to speak calmly. "Progress? In less than two months? Hummin, this is something that might easily take me my whole life and the lives of the next dozen who follow me.-And even then end in failure."

"I'm not talking about anything as final as a solution or even as hopeful as the beginning of a solution. You've said flatly a number of times that a useful psychohistory is possible but impractical. All I am asking is whether there now seems any hope that it can be made practical."

"Frankly, no."

Dors said, "Please excuse me. I am not a mathematician, so I hope this is not a foolish question. How can you know something is both possible and impractical? I've heard you say that, in theory, you might personally meet and greet all the people in the Empire, but that it is not a practical feat because you couldn't live long enough to do it. But how can you tell that psychohistory is something of this sort?"

Seldon looked at Dors with some incredulity. "Do you want that explained."

"Yes," she said, nodding her head vigorously so that her curled hair vibrated.

"As a matter of fact," said Hummin, "so would I."

"Without mathematics?" said Seldon with just a trace of a smile.

"Please," said Hummin.

"Well-" He retired into himself to choose a method of presentation. Then he said, "-If you want to understand some aspect of the Universe, it helps if you simplify it as much as possible and include only those properties and characteristics that are essential to understanding. If you want to determine how an object drops, you don't concern yourself with whether it is new or old, is red or green, or has an odor or not. You eliminate those things and thus do not needlessly complicate matters. The simplification you can call a model or a simulation and you can present it either as an actual representation on a computer screen or as a mathematical relationship. If you consider the primitive theory of nonrelativistic gravitation-"

Dors said at once, "You promised there would be no mathematics. Don't try to slip it in by calling it 'primitive.' "

"No, no. I mean 'primitive' only in that it has been known as long as our records go back, that its discovery is shrouded in the mists of antiquity as is that of fire or the wheel. In any case, the equations for such gravitational theory contain within themselves a description of the motions of a planetary system, of a double star, of tides, and of many other things. Making use of such equations, we can even set up a pictorial simulation and have a planet circling a star or two stars circling each other on a two-dimensional screen or set up more complicated systems in a three-dimensional holograph. Such simplified simulations make it far easier to grasp a phenomenon than it would be if we had to study the phenomenon itself. In fact, without the gravitational equations, our knowledge of planetary motions and of celestial mechanics generally would be sparse indeed.

"Now, as you wish to know more and more about any phenomenon or as a phenomenon becomes more complex, you need more and more elaborate equations, more and more detailed programming, and you end with a computerized simulation that is harder and harder to grasp."

"Can't you form a simulation of the simulation?" asked Hummin. "You would go down another degree."

"In that case, you would have to eliminate some characteristic of the phenomenon which you want to include and your simulation becomes useless. The LPS-that is, 'the least possible simulation' gains in complexity faster than the object being simulated does and eventually the simulation catches up with the phenomenon. Thus, it was established thousands of years ago that the Universe as a whole, in its full complexity, cannot be represented by any simulation smaller than itself.

"In other words, you can't get any picture of the Universe as a whole except by studying the entire Universe. It has been shown also that if one attempts to substitute simulations of a small part of the Universe, then another small part, then another small part, and so on, intending to put them all together to form a total picture of the Universe, one would find that there are an infinite number of such part simulations. It would therefore take an infinite time to understand the Universe in full and that is just another way of saying that it is impossible to gain all the knowledge there is."

"I understand you so far," said Dors, sounding a little surprised.

"Well then, we know that some comparatively simple things are easy to simulate and as things grow more and more complex they become harder to simulate until finally they become impossible to simulate. But at what level of complexity does simulation cease to be possible? Well, what I have shown, making use of a mathematical technique first invented in this past century and barely usable even if one employs a large and very fast computer, our Galactic society falls short of that mark. It can be represented by a simulation simpler than itself. And I went on to show that this would result in the ability to predict future events in a statistical fashion-that is, by stating the probability for alternate sets of events, rather than flatly predicting that one set will take place."

"In that case," said Hummin, "since you can profitably simulate Galactic society, it's only a matter of doing so. Why is it impractical?"

"All I have proved is that it will not take an infinite time to understand Galactic society, but if it takes a billion years it will still be impractical. That will be essentially the same as infinite time to us."

"Is that how long it would take? A billion years?"

"I haven't been able to work out how long it would take, but I strongly suspect that it will take at least a billion years, which is why I suggested that number."

"But you don't really know."

"I've been trying to work it out."

"Without success?"

"Without success."

"The University library does not help?" Hummin cast a look at Dors as he asked the question.

Seldon shook his head slowly. "Not at all."

"Dors can't help?"

Dors sighed. "I know nothing about the subject, Chetter. I can only suggest ways of looking. If Hari looks and doesn't find, I am helpless."

Hummin rose to his feet. "In that case, there is no great use in staying here at the University and I must think of somewhere else to place you."

Seldon reached out and touched his sleeve. "Still, I have an idea."

Hummin stared at him with a faint narrowing of eyes that might have belied surprise-or suspicion. "When did you get the idea? Just now?"

"No. It's been buzzing in my head for a few days before I went Upperside. That little experience eclipsed it for a while, but asking about the library reminded me of it."

Hummin seated himself again. "Tell me your idea-if it's not something that's totally marinated in mathematics."

"No mathematics at all. It's just that reading history in the library reminded me that Galactic society was less complicated in the past. Twelve thousand years ago, when the Empire was on the way to being established, the Galaxy contained only about ten million inhabited worlds. Twenty thousand years ago, the pre-Imperial kingdoms included only about ten thousand worlds altogether. Still deeper in the past, who knows how society shrinks down? Perhaps even to a single world as in the legends you yourself once mentioned, Hummin."

Hummin said, "And you think you might be able to work out psychohistory if you dealt with a much simpler Galactic society?"

"Yes, it seems to me that I might be able to do so."

"Then too," said Dors with sudden enthusiasm, "suppose you work out psychohistory for a smaller society of the past and suppose you can make predictions from a study of the pre-Imperial situation as to what might happen a thousand years after the formation of the Empire-you could then check the actual situation at that time and see how near the mark you were."

Hummin said coldly, "Considering that you would know in advance the situation of the year 1,000 of the Galactic Era, it would scarcely be a fair test. You would be unconsciously swayed by your prior knowledge and you would be bound to choose values for your equation in such a way as to give you what you would know to be the solution."

"I don't think so," said Dors. "We don't know the situation in 1,000 G.E. very well and we would have to dig. After all, that was eleven millennia ago."

Seldon's face turned into a picture of dismay. "What do you mean we don't know the situation in 1,000 G.E. very well? There were computers then, weren't there, Dors?"

"Of course."

"And memory storage units and recordings of ear and eye? We should have all the records of 1,000 G.E. as we have of the present year of 12,020 G.E."

"In theory, yes, but in actual practice- Well, you know, Hari, it's what you keep saying. It's possible to have full records of 1,000 G.E., but it's not practical to expect to have it."

"Yes, but what I keep saying, Dors, refers to mathematical demonstrations. I don't see the applications to historical records."

Dors said defensively, "Records don't last forever, Hari. Memory banks can be destroyed or defaced as a result of conflict or can simply deteriorate with time. Any memory bit, any record that is not referred to for a long time, eventually drowns in accumulated noise. They say that fully one third of the records in the Imperial Library are simply gibberish, but, of course, custom will not allow those records to be removed. Other libraries are less tradition-bound. In the Streeling University library, we discard worthless items every ten years.

"Naturally, records frequently referred to and frequently duplicated on various worlds and in various libraries-governmental and private-remain clear enough for thousands of years, so that many of the essential points of Galactic history remain known even if they took place in pre-Imperial times. However, the farther back you go, the less there is preserved."

"I can't believe that," said Seldon. "I should think that new copies would be made of any record in danger of withering. How could you let knowledge disappear?"

"Undesired knowledge is useless knowledge," said Dors. "Can you imagine all the time, effort, and energy expended in a continual refurbishing of unused data? And that wastage would grow steadily more extreme with time."

"Surely, you would have to allow for the fact that someone at some time might need the data being so carelessly disposed of."

"A particular item might be wanted once in a thousand years. To save it all just in case of such a need isn't cost-effective. Even in science. You spoke of the primitive equations of gravitation and say it is primitive because its discovery is lost in the mists of antiquity. Why should that be? Didn't you mathematicians and scientists save all data, all information, back and back to the misty primeval time when those equations were discovered?"

Seldon groaned and made no attempt to answer. He said, "Well, Hummin, so much for my idea. As we look back into the past and as society grows smaller, a useful psychohistory becomes more likely. But knowledge dwindles even more rapidly than size, so psychohistory becomes less likely-and the less outweighs the more."

"To be sure, there is the Mycogen Sector," said Dors, musing.

Hummin looked up quickly. "So there is and that would be the perfect place to put Seldon. I should have thought of it myself."

"Mycogen Sector," repeated Hari, looking from one to the other. "What and where is Mycogen Sector?"

"Hari, please, I'll tell you later. Right now, I have preparations to make. You'll leave tonight."

33.

Dors had urged Seldon to sleep a bit. They would be leaving halfway between lights out and lights on, under cover of "night," while the rest of the University slept. She insisted he could still use a little rest.

"And have you sleep on the floor again?" Seldon asked.

She shrugged. "The bed will only hold one and if we both try to crowd into it, neither of us will get much sleep."

He looked at her hungrily for a moment and said, "Then I'll sleep on the floor this time."

"No, you won't. I wasn't the one who lay in a coma in the sleet."

As it happened, neither slept. Though they darkened the room and though the perpetual hum of Trantor was only a drowsy sound in the relatively quiet confines of the University, Seldon found that he had to talk. He said, "I've been so much trouble to you, Dors, here at the University. I've even been keeping you from your work. Still, I'm sorry I'll have to leave you."

Dors said, "You won't leave me. I'm coming with you. Hummin is arranging a leave of absence for me."

Seldon said, dismayed, "I can't ask you to do that."

"You're not. Hummin's asking it. I must guard you. After all, I faded in connection with Upperside and should make up for it."

"I told you. Please don't feel guilty about that.-Still, I must admit I would feel more comfortable with you at my side. If I could only be sure I wasn't interfering with your life..."

Dors said softly, "You're not, Hari. Please go to sleep."

Seldon lay silent for a while, then whispered, "Are you sure Hummin can really arrange everything, Dors?"

Dors said, "He's a remarkable man. He's got influence here at the University and everywhere else, I think. If he says he can arrange for an indefinite leave for me, I'm sure he can. He is a most persuasive man."

"I know," said Seldon. "Sometimes I wonder what he really wants of me."

"What he says," said Dors. "He's a man of strong and idealistic ideas and dreams."

"You sound as though you know him well, Dors."

"Oh yes, I know him well."

"Intimately?"

Dors made an odd noise. "I'm not sure what you're implying, Hari, but, assuming the most insolent interpretation- No, I don't know him intimately. What business would that be of yours anyway?"

"I'm sorry," said Seldon. "I just didn't want, inadvertently, to be invading someone else's-"

"Property? That's even more insulting. I think you had better go to sleep."

"I'm sorry again, Dors, but I can't sleep. Let me at least change the subject. You haven't explained what the Mycogen Sector is. Why will it be good for me to go there? What's it like?"

"It's a small sector with a population of only about two million-if I remember correctly. The thing is that the Mycogenians cling tightly to a set of traditions about early history and are supposed to have very ancient records not available to anyone else. It's just possible they would be of more use to you in your attempted examination of pre-Imperial times than orthodox historians might be. All our talk about early history brought the sector to mind."

"Have you ever seen their records?"

"No. I don't know anyone who has."

"Can you be sure that the records really exist, then?"

"Actually, I can't say. The assumption among non-Mycogenians is that they're a bunch of madcaps, but that may be quite unfair. They certainly say they have records, so perhaps they do. In any case, we would be out of sight there. The Mycogenians keep strictly to themselves.-And now please do go to sleep."

And somehow Seldon finally did.

34.

Hari Seldon and Dors Venabili left the University grounds at 0300. Seldon realized that Dors had to be the leader. She knew Trantor better than he did-two years better. She was obviously a close friend of Hummin (how close? the question kept nagging at him) and she understood his instructions. Both she and Seldon were swathed in light swirling docks with tight-fitting hoods. The style had been a short-lived clothing fad at the University (and among young intellectuals, generally) some years back and though right now it might provoke laughter, it had the saving grace of covering them well and of making them unrecognizable-at least at a cursory glance.

Hummin had said, "There's a possibility that the event Upperside was completely innocent and that there are no agents after you, Seldon, but let's be prepared for the worst."

Seldon had asked anxiously, "Won't you come with us?"

"I would like to," said Hummin, "but I must limit my absence from work if I am not to become a target myself. You understand?"

Seldon sighed. He understood.

They entered an Expressway car and found a seat as far as possible from the few who had already boarded. (Seldon wondered why anyone should be on the Expressways at three in the morning-and then thought that it was lucky some were or he and Dors would be entirely too conspicuous.)

Seldon fell to watching the endless panorama that passed in review as the equally endless line of coaches moved along the endless monorail on an endless electromagnetic field.

The Expressway passed row upon row of dwelling units, few of them very tall, but some, for all he knew, very deep. Still, if tens of millions of square kilometers formed an urbanized total, even forty billion people would not require very tall structures or very closely packed ones. They did pass open areas, in most of which crops seemed to be growing-but some of which were clearly parklike. And there were numerous structures whose nature he couldn't guess. Factories? Office buildings? Who knew? One large featureless cylinder struck him as though it might be a water tank. After all, Trantor had to have a fresh water supply. Did they sluice rain from Upperside, filter and treat it, then store it? It seemed inevitable that they should. Seldon did not have very long to study the view, however.

Dors muttered, "This is about where we should be getting off." She stood up and her strong fingers gripped his arm.

They were off the Expressway now, standing on solid flooring while Dors studied the directional signs.

The signs were unobtrusive and there were many of them. Seldon's heart sank. Most of them were in pictographs and initials, which were undoubtedly understandable to native Trantorians, but which were alien to him.

"This way," said Dors.

"Which way? How do you know?"

"See that? Two wings and an arrow."

"Two wings? Oh." He had thought of it as an upside-down "w," wide and shallow, but he could see where it might be the stylized wings of a bird. "Why don't they use words?" he said sullenly.

"Because words vary from world to world. What an 'air-jet' is here could be a 'soar' on Cinna or a 'swoop' on other worlds. The two wings and an arrow are a Galactic symbol for an air vessel and the symbol is understood everywhere. Don't you use them on Helicon?"

"Not much. Helicon is a fairly homogeneous world, culturally speaking, and we tend to cling to our private ways firmly because we're overshadowed by our neighbors."

"See?" said Dors. "There's where your psychohistory might come in. You could show that even with different dialects the use of set symbols, Galaxy-wide, is a unifying force."

"That won't help." He was following her through empty dim alleyways and part of his mind wondered what the crime rate might be on Trantor and whether this was a high-crime area. "You can have a billion rules, each covering a single phenomenon, and you can derive no generalizations from that. That's what one means when one says that a system might be interpreted only by a model as complex as itself.-Dors, are we heading for an air-jet?"

She stopped and turned to look at him with an amused frown. "If we're following the symbols for air-jets, do you suppose we're trying to reach a golf course? Are you afraid of air-jets in the way so many Trantorians are?"

"No, no. We fly freely on Helicon and I make use of air-jets frequently. It's just that when Hummin took me to the University, he avoided commercial air travel because he thought we would leave too clear a trail."

"That's because they knew where you were to begin with, Hari, and were after you already. Right now, it may be that they don't know where you are and we're using an obscure port and a private air-jet."

"And who'll be doing the flying?"

"A friend of Hummin's, I presume."

"Can he be trusted, do you suppose?"

"If he's a friend of Hummin's, he surely can."

"You certainly think highly of Hummin," said Seldon with a twinge of discontent.

"With reason," said Dors with no attempt at coyness. "He's the best."

Seldon's discontent did not dwindle.

"There's the air-jet," she said.

It was a small one with oddly shaped wings. Standing beside it was a small man, dressed in the usual glaring Trantorian colors.

Dors said, "We're psycho."

The pilot said, "And I'm history."

They followed him into the air-jet and Seldon said, "Whose idea were the passwords?"

"Hummin's," said Dors.

Seldon snorted. "Somehow I didn't think Hummin would have a sense of humor. He's so solemn."

Dors smiled.