"may i interrupt you, yugo?"

"of course, dors," said yugo amaryl with a large smile. "you are lover an interruption. what can i do for you?"

"i am trying to find out a few things, yugo, and i wonder if you would humor me in this."

"if i can."

"you have something in the project called the prime radiant. i hear it now and then. hari speaks of it, so i imagine i know what it looks like when it is activated, but i have never actually seen it in operation. i would like to."

amaryl looked uncomfortable. "actually the prime radiant is just about the most closely guarded part of the project and you aren't on the list of the members who have access."

"i know that, but we've known each other for twenty-eight years-"

"and you're hari's wife. i suppose we can stretch a point. we only have two full prime radiants. there's one in hari's office and one here. right there, in fact."

dors looked at the squat black cube on the central desk. it looked utterly undistinguished. "is that it?"

"that's it. it stores the equations that describe the future."

"how do you get at those equations?"

amaryl moved a contact and at once the room darkened and then came to life in a variegated glow. all around dors were symbols, arrows, mathematical signs of one sort or another. they seemed to be moving, spiraling, but when she focused her eyes on any particular portion, it seemed to be standing still.

she said, "is that the future, then?"

"it may be," said amaryl, turning off the instrument. "i had it at full expansion so you could see the symbols. without expansion, nothing is visible but patterns of light and dark."

"and by studying those equations, you are able to judge what the future holds in store for us?"

"in theory." the room was now back to its mundane appearance. "but there are two difficulties."

"oh? what are they?"

"to begin with, no human mind has created those equations directly. we have merely spent decades programming more powerful computers and they have devised and stored the equations, but, of course, we don't know if they are valid and have meaning. it depends entirely on how valid and meaningful the programming is in the first place."

"they could be all wrong, then?"

"they could be." amaryl rubbed his eyes and dors could not help thinking how old and tired he seemed to have grown in the last couple of years. he was younger than hari by nearly a dozen years, but he seemed much older.

"of course," amaryl went on in a rather weary voice, "we hope that they aren't all wrong, but that's where the second difficulty comes in. although hari and i have been testing and modifying them for decades, we can never be sure what the equations mean. the computer has constructed them, so it is to be presumed they must mean something-but what? there are portions that we think we have worked out. in fact, right now, i'm working on what we call section a-23, a particularly knotty system of relationships. we have not yet been able to match it with anything in the real universe. still, each year sees us further advanced and i look forward confidently to the establishment of psychohistory as a legitimate and useful technique for dealing with the future."

"how many people have access to these prime radiants?"

"every mathematician in the project has access but not at will. there have to be applications and time allotted and the prime radiant has to be adjusted to the portion of the equations a mathematician wishes to refer to. it gets a little complicated when everyone wants to use the prime radiant at the same time. right now, things are slow, possibly because we're still in the aftermath of hari's birthday celebration."

"is there any plan for constructing additional prime radiants?"

amaryl thrust out his lips. "yes and no. it would be very helpful if we had a third, but someone would have to be in charge of it. it can't just be a community possession. i have suggested to hari that tamwile elar-you know him, i think-"

"yes, i do."

"that elar have a third prime radiant. his achaotic equations and the electro-clarifier he thought up make him clearly the third man in the project after hari and myself. hari hesitates, however."

"why? do you know?"

"if elar gets one, he is openly recognized as the third man, over the head of other mathematicians who are older and who have more senior status in the project. there might be some political difficulties, so to speak. i think that we can't waste time in worrying about internal politics, but hari- well, you know hari."

"yes, i know hari. suppose i tell you that linn has seen the prime radiant."

"linn?"

"colonel hender linn of the junta. tennar's lackey."

"i doubt that very much, dors."

"he has spoken of spiraling equations and i have just seen them produced by the prime radiant. i can't help but think he's been here and seen it working."

amaryl shook his head, "i can't imagine anyone bringing a member of the junta into hari's office-or mine."

"tell me, who in the project do you think is capable of working with the junta in this fashion?"

"no one," said amaryl flatly and with clearly unlimited faith. "that would be unthinkable. perhaps linn never saw the prime radiant but was merely told about it."

"who would tell him about it?"

amaryl thought a moment and said, "no one."

"well now, you talked about internal politics a while ago in connection with the possibility of elar having a third prime radiant. i suppose in a project such as this one with hundreds of people, there are little feuds going on all the time-frictions-quarrels."

"oh yes. poor hari talks to me about it every once in a while. he has to deal with them in one way or another and i can well imagine what a headache it must be for him."

"are these feuds so bad that they interfere with the working of the project?"

"not seriously."

"are there any people who are more quarrelsome than others or any duo draw more resentment than others? in short, are there people you can get rid of and perhaps remove 90 percent of the friction at the cost of 5 or 6 percent of the personnel?"

amaryl raised his eyebrows. "it sounds like a good idea, but i don't know whom to get rid of. i don't really participate in all the minutiae of internal politics. there's no way of stopping it, so for my part, i merely avoid it."

"that's strange," said dors. "aren't you in this way denying any credibility to psychohistory?"

"in what way?"

"how can you pretend to reach a point where you can predict and guide the future, when you cannot analyze and correct something as homegrown as personal frictions in the very project that promises so much?"

amaryl chuckled softly. it was unusual, for he was not a man who was given to humor and laughter. "i'm sorry, dors, but you picked on the one problem that we have solved, after a manner of speaking. hari himself identified the equations that represented the difficulties of personal friction years ago and i myself then added the final touch last year.

"i found that there were ways in which the equations could be changed so as to indicate a reduction in friction. in every such case, however, a reduction in friction here meant an increase in friction there. never at any time was there a total decrease or, for that matter, a total increase in the friction within a closed group-that is, one in which no old members leave and no new members come in. what i proved, with the help of elar's achaotic equations, was that this was true despite any conceivable action anyone could take. hari calls it `the law of conservation of personal problems.'

"it gave rise to the notion that social dynamics has its conservation laws as physics does and that, in fact, it is these laws that offer us the best possible tools for solving the truly troublesome aspects of psychohistory."

dors said, "rather impressive, but what if you end up finding that nothing at all can be changed, that everything that is bad is conserved, and that to save the empire from destruction is merely to increase destruction of another kind?"

"actually some have suggested that, but i don't believe it."

"very well. back to reality. is there anything in the frictional problems within the project that threaten hari? i mean, with physical harm."

"harm hari? of course not. how can you suggest such a thing?"

"might there not be some who resent hari, for being too arrogant, too pushy, too self-absorbed, too eager to grab all the credit? or, if none of these things apply, might they not resent him simply because he has run the project for so long a time?"

"i never heard anyone say such a thing about hari."

dors seemed dissatisfied. "i doubt that anyone would say such things in your hearing, of course. but thank you, yugo, for being so helpful and for giving me so much of your time."

amaryl stared after her as she left. he felt vaguely troubled, but then returned to his work and let other matters drift away.