PART IV. AURORA

11. THE OLD LEADER

48

Kelden Amadiro was not immune from the human plague of memory. He was, in fact, more subject to it than most. In his case, moreover, the tenacity of memory had, as its accompaniment, a content unusual for the intensity of its deep and prolonged rage and frustration.

All had been going so well for him twenty decades before. He was the founding head of the Robotics Institute (he was still the founding head) and for one flashing and triumphant moment it had seemed to him that he could not fail to achieve total control of the Council, smashing his great enemy, Han Fastolfe, and leaving him in helpless opposition.

If he had - if he only had -

(How he tried not to think of it and, how his memory presented him with it, over and over again, as though it could never get enough of grief and despair.)

If he had won out, Earth would have remained isolated and alone and he would have seen to it that Earth declined, decayed, and finally faded into dissolution. Why not? The short-lived people of a diseased, overcrowded world were better off dead - a hundred times better off dead than living the life they had forced themselves to lead.

And the Spacer worlds, calm and secure, would then have expanded further, Fastolfe had always complained that the Spacers were too long-lived and too comfortable on their robotic cushions to be pioneers, but Amadiro would have proved him wrong.

Yet Fastolfe had won out. At the moment of certain defeat, he had somehow, unbelievably, incredibly, reached into empty space, so to speak, and found victory in his grasp - plucked from nowhere.

It was that Earthman, of course, Elijah Baley -

But Amadiro's otherwise uncomfortable memory always balked at the Earthman and turned away. He could not picture that face, hear that voice, remember that deed. The name was enough. Twenty centuries had not sufficed to dim the hatred he felt in the slightest - or to soften the pain he felt by an iota.

And with Fastolfe in charge of policy, the miserable Earthmen had fled their corrupting planet and established themselves on world after world. The whirlwind of Earth's progress dazed the Spacer worlds and forced them into frozen paralysis.

How many times had Amadiro addressed the Council and pointed out that the Galaxy was slipping from Spacer fingers, that Aurora was watching blankly while world after world was being occupied by submen, that each year apathy was taking firmer hold of the Spacer spirit?

"Rouse yourself," he had called out. "Rouse yourself. See their numbers grow. See the Settler worlds multiply. What is it you wait for? To have them at your throats?"

And always Fastolfe would answer in that soothing lullaby of a voice of his and the Aurorans and the other Spacers (always following Aurora's lead, when Aurora chose not to lead) would settle back and return to their slumber.

The obvious did not seem to touch them. The facts, the figures, the indisputable worsening of affairs from decade to decade left them unmoved. How was it possible to shout the truth at them so steadily, to have every prediction he made come to pass, and yet to have to watch a steady majority following Fastolfe like sheep?

How was it possible that Fastolfe himself could watch everything he said prove to be sheer folly and yet never swerve from his policies? It was not even that he stubbornly insisted on being wrong, it was that he simply never seemed to notice he was wrong.

If Amadiro were the kind of man who doted on fantasy, he would surely imagine that some kind of spell, some kind of apathetic enchantment, had fallen upon the Spacer worlds. He would imagine that somewhere someone possessed the magic power of lulling otherwise active brains and blinding to the truth otherwise sharp eyes.

To add the final exquisite agony, people pitied Fastolfe for having died in frustration. In frustration, they said, because the Spacers would not seize new worlds of their own.

It was Fastolfe's own policies that kept them from doing so! What right had he to feel frustration over that? What would he do if he had, like Amadiro, always seen and spoken the truth and been unable to force the Spacers enough Spacers - to listen to him.

How many times had he thought that it would be better for the Galaxy to be empty than under the domination of the submen? Had he had some magic power to destroy the Earth - Elijah Baley's world - with a nod of his head, how eagerly he would.

Yet to find refuge in such fantasy could only be a sign of his total despair. It was the other side of his recurrent, futile wish Ito give up and welcome death - if his robots would allow it.

And then the time came when the power to destroy Earth was given him - even forced upon him against his will. That time was some three-fourths of a decade before, when he had first met Levular Mandamus.

49

Memory! Three-fourths of a decade before -

Amadiro looked up and noted that Maloon Cicis had entered the office. He had undoubtedly signaled and he had the right to enter if the signal were not acknowledged.

Amadiro sighed and put down his small computer. Cicis had been his right-hand man ever since the Institute had been established. He was getting old in his service. Nothing drastically noticeable, just a general air of mild decay. His nose seemed to be a bit more asymmetrical than it once had been.

He rubbed his own somewhat bulbous nose and wondered how badly the flavor of decay was enveloping him. He had once been 1.95 meters tall, a good height even by Spacer standards. Surely he stood as straight now as he always had and yet when he had actually measured his height recently, he could not manage to make it more than 1.93 meters. Was he beginning to stoop, to shrivel, to settle?

He put away these dour thoughts that were themselves a surer sign of aging than mere measurements and said, "What is it, Maloon?"

Cicis had a new personal robot dogging his steps very modernistic and with glossy trim. That was a sign of aging, too. If one can't keep one's body young, one can always buy a new young robot. Amadiro was determined never to rouse smiles among the truly young by falling prey to that particular delusion - especially since Fastolfe, who was eight decades older than Amadiro, had never done so.

Cicis said, "It's this Mandamus fellow again, Chief."

"Mandamus?"

"The one who keeps wanting to see you."

Amadiro thought a while. "You mean the idiot who's a descendant of the Solarian woman?"

"Yes, Chief."

"Well, I don't want to see him. Haven't you made that clear to him yet, Maloon?"

"Abundantly clear. He asks that I hand you a note and he says you will then see him."

Amadiro said slowly, "I don't think so, Maloon. What does the note say?"

"I don't understand it, Chief. It isn't Galactic."

"In that case, why should I understand it any more than you do?"

"I don't know, but he asked me to give it to you. If you care to look at it, Chief, and say the word, I will go back and get rid of him one more time."

"Well, then, let me see it," said Amadiro, shaking his head. He glanced at it with distaste.

It read: "Ceterum censeo, delenda est Carthago."

Amadiro read the message, glared up at Maloon, then turned his eyes back to the message. Finally, he said, "You must have looked at this, since you know it isn't Galactic. Did you ask him what it meant?"

"Yes, I did, Chief. He said it was Latin, but that left me no wiser. He said you would understand. He is a very determined man and said he would sit there all day waiting till you read this."

"What does he look like?"

"Thin. Serious. Probably humorless. Tall, but not quite as tall as you. Intense, deep-set eyes, thin lips."

"How old is he?"

"From the texture of his skin, I should say four decades or so. He is very young."

"In that case, we must make allowances for youth. Send him in."

Cicis looked surprised. "You will see him?"

"I have just said so, haven't I? Send him in."

50

The young man entered the room in what was almost a march step. He stood there stiffly in front of the desk and said, "I thank you, sir, for agreeing to see me. May I have your permission to have my robots join me?"

Amadiro raised his eyebrows. "I would be pleased to see them. Would you permit me to keep mine with me?"

It had been many years since he had heard anyone mouth the old robot formula. It was one of those good old customs that sank into abeyance as the notion of formal politeness decayed and as it came to be taken more and more for granted that one's personal robots were part of one's self.

"Yes, sir," said Mandamus and two robots entered. They did not do so, Amadiro noted, till permission had been given. They were new robots, clearly efficient, and showed all the signs of good workmanship.

"Your own design, Mr. Mandamus?" There was always some extra value in robots that were designed by their owners.

"Indeed, sir."

"Then you are a roboticist?"

"Yes, sir. I have my degree from the University of Eons."

"Working under - "

Mandamus said smoothly, "Not under Dr. Fastolfe, sir. Under Dr. Maskellnik."

"Ah, but you are not a member of the Institute."

"I have applied for entrance, sir."

"I see." Amadiro adjusted the papers on his desk and then said quickly, without looking up, "Where did you learn Latin?"

"I do not know Latin well enough to speak it or read it but I know enough about it to know that quotation and where to find it."

"That in itself is remarkable. How does that come about?"

"I cannot devote every moment of my time to robotics, so I have my side interests. One of them is planetology, with particular reference to Earth. That led me to Earth's history and culture."

"That is not a popular study among Spacers."

"No, sir, and that is too bad. One should always know one's enemies - as you do, sir."

"As I do?"

"Yes, sir. I believe you are acquainted with many aspects of Earth and are more learned in that respect than I am, for you have studied the subject longer."

"How do you know that?"

"I have tried to learn as much about you as I can, sir."

"Because I am another one of your enemies?"

"No, sir, but because I want to make you an ally."

"Make me an ally? You plan to make use of me, then? Does it strike you that you are being a little impertinent?"

"No, sir, for I am sure you will want to be an ally of mine."

Amadiro stared at him. "Nevertheless, it strikes me that you are being rather more than a little impertinent. - Tell me, do you understand this quotation you have found for me?"

"Yes, sir."

"Then translate it into Standard Galactic."

"It says, 'In my opinion, Carthage must be destroyed.'"

"And what does that mean, in your opinion?"

"The speaker was Marcus Porcius Cato, a senator of the Roman Republic, a political unit of ancient Earth. It had defeated its chief rival, Carthage, but had not destroyed it. Cato held that Rome could not be secure until Carthage was entirely destroyed - and eventually, sir, it was."

"But what is Carthage to us, young man?"

"There are such things as analogies."

"Which means?"

"That the Spacer worlds, too, have a chief rival that, in my opinion, must be destroyed."

"Name the enemy."

"The planet Earth, sir."

Amadiro drummed his fingers very softly upon the desk before him. "And you want me to be your ally in such a project. You assume I will be happy and eager to be one. - Tell me, Dr. Mandamus, when have I ever said in any of my numerous speeches and writings on the subject that Earth must be destroyed?"

Mandamus's thin lips tightened and his nostrils flared. "I am not here," he said, "in an attempt to trap you into something that can be used against you. I have not been sent here by Dr. Fastolfe, or any of his party. Nor am I of his party. Nor do I attempt to say what is in your mind. I tell you only what is in my mind. In my opinion, Earth must be destroyed."

"And how do you propose to destroy Earth? Do you suggest that we drop nuclear bombs on it until the blasts and radiation and dust clouds destroy the planet? Because, if so, how do you propose to keep avenging Settler ships from doing the same to Aurora and to as many of the other Spacer worlds as they can reach? Earth might have been blasted with impunity as recently as fifteen decades ago. It can't be now."

Mandamus looked revolted. "I have nothing like that in mind, Dr. Amadiro. I would not unnecessarily destroy human beings, even if they are Earthpeople. There is a way, however, in which Earth can be destroyed without necessarily killing its people wholesale - and there will be no retaliation."

"You are a dreamer," said Amadiro, "or perhaps not quite sane."

"Let me explain."

"No, young man. I have little time and because your quotation, which I understood perfectly well, piqued my curiosity, I have already allowed myself to spend too much of it on you."

Mandamus stood up. "I understand, Dr. Amadiro, and I beg your pardon for taking up more of your time than you could afford. Think of what I have said, however, and if you should become curious, why not call upon me when you have more time to devote to me than you now have. Do not wait too long, however, for if I must, I will turn in other directions, for destroy Earth I will. I am frank with you, you see."

The young man attempted a smile that stretched his thin cheeks without producing much of an effect on his face otherwise. He said, "Good-bye - and thank you again," turned, and left.

Amadiro looked after him for a while thoughtfully, then touched a contact on the side of his desk.

"Maloon," he said when Cicis entered, "I want that young man watched around the clock and I want to know everyone he speaks to - everyone. I want them all identified and I want them all questioned. Those whom I indicate are to be brought to me. - But, Maloon, everything must be done quietly and with an attitude of sweet and friendly persuasion. I am not yet master here, as you know."

But he would be eventually. Fastolfe was thirty-six decades old and clearly failing and Amadiro was eight decades younger.

51

Amadiro received his reports for nine days.

Mandamus talked to his robots, occasionally to colleagues at the university, and even more occasionally to individuals at the establishments neighboring his. His conversations were utterly trivial and, long before the nine days had passed, Amadiro had decided he could not outwait the young man. Mandamus was only at the beginning of a long life and might have thirty decades ahead of him; Amadiro had only eight to ten at the very most.

And Amadiro, thinking of what the young man had said, felt, with increasing restlessness, that he could not take the chance that a way of destroying Earth might exist and, that he might be ignoring it. Could he allow the destruction to take place after his death, so that he would not witness it? Or, almost as bad, have it take place during his lifetime, but with someone else's mind in command, someone else's fingers on the contact?

No, he had to see it, witness it, and do it, else why had he endured his long frustration? Mandamus might be a fool or a madman, but, in that case, Amadiro had to know for certain that he was a fool or a madman.

Having reached that point in his thinking, Amadiro called Mandamus to his office.

Amadiro realized that in so doing, he was humiliating himself, but the humiliation was the price he had to pay to make certain that there wasn't the slightest chance of Earth being destroyed without him. It was a price he was willing to pay -

He steeled himself even for the possibility that Mandamus would enter his presence, smirking and contemptuously triumphant. He would have to endure that, too. After the endurance, of course, if the young man's suggestion proved foolish, he would see him punished to the full extent that a civilized society would permit, but otherwise -

He was pleased, then, when Mandamus entered his office with an attitude of reasonable humility and thanked him, in all apparent sincerity, for a second interview. It seemed to Amadiro he would have to be gracious in his turn.

"Dr. Mandamus," he said, "in sending you away without listening to your plan, I was guilty of discourtesy. Tell me, then, what you have in mind and I will listen until it is quite clear to me - as I suspect it will be - that your plan is, perhaps, more the result of enthusiasm than of cold reason. At that time, I will dismiss you again, but without contempt on my part, and I hope that you will respond without anger on your part."

Mandamus said, "I could not be angry at having been accorded a fair and patient hearing, Dr. Amadiro, but what if what I say makes sense to you and offers hope?"

"In that case," said Amadiro slowly, "it would be conceivable that we two could work together."

"That would be wonderful, sir. Together we could accomplish more than we could separately. But would there be something more tangible than the privilege of working together? Would there be a reward?"

Amadiro looked displeased. "I would be grateful, of course, but all I am is a Councilman and the head of the Robotics Institute. There would be a limit to what I could do for you."

"I understand that, Dr. Amadiro. But within those limits could I not have something on account? Now?" He looked at Amadiro steadily.

Amadiro frowned at finding himself gazing into a pair of keen and unblinkingly determined eyes. No humility there!

Amadiro said coldly, "What do you have in mind?"

"Nothing you can't give me, Dr. Amadiro. Make me a member of the Institute."

"If you qualify - "

"No fear. I qualify."

"We can't leave that decision to the candidate. We have to - "

"Come, Dr. Amadiro, this is no way to begin a relationship. Since you've had me under observation every moment since I left you last, I can't believe you haven't studied my record thoroughly. As a result, you must know I qualify. If, for any reason, you felt I did not qualify, you would have no hope whatever that I would be ingenious enough to work out a plan for the destruction of our particular Carthage and I wouldn't be back here at your call."

For an instant, Amadiro felt a fire blaze within him. For that instant, he felt that even Earth's destruction was not worth enduring this hectoring attitude from a child. But only for that instant. Then his sense of due proportion was back and he could even tell himself that a person so young, yet so bold and so icily sure of himself, was the kind of man he needed. Besides, he had studied Mandamus's record and there was no question that he qualified for the Institute.

Amadiro said evenly (at some cost to his blood pressure), "You are right. You qualify."

"Then enroll me. I'm sure you have the necessary forms in your computer. You have but to enter my name, my school, my year of graduation, and whatever other statistical trivia you require and then sign your own name."

Without a word in reply, Amadiro turned to his computer. He entered the necessary information, retrieved the form, signed it, and handed it to Mandamus. "It is dated today. You are a fellow of the Institute."

Mandamus studied the paper, then handed it to one of his robots, who placed it in a small portfolio which he then placed under his ann.

"Thank you," said Mandamus, "it is most kind of you and I hope I will never fail you or cause you to regret this kind estimate you have given me of my abilities. That, however, leaves one more thing."

"Indeed? What?"

"Might we discuss the nature of the final reward - in case of success only, of course. Total success.

"Might we not leave that, more logically, to the point where total success is achieved or is reasonably close to being achieved?"

"As a matter of rationality, yes. But I am a creature of dreams as well as of reason. I would like to dream a little.

"Well," said Amadiro, "what is it you would like to dream?"

"It seems to me, Dr. Amadiro, that Dr. Fastolfe is now by no means well. He has lived long and cannot stave off death for many more years."

"And if so?"

"Once he dies, your party will become more aggressive and the more lukewarm members of Fastolfe's party will find it expedient to change allegiance, perhaps. The next election, without Fastolfe, will surely be yours."

"It is possible. And if so?"

"You will become the de facto leader of the Council and the guide of Aurora's foreign policy which would, in fact, mean the foreign policy of the Spacer worlds in general. And if my plans flourish, your direction will be so successful that the Council will scarcely fail to elect you Chairman at their earliest opportunity."

"Your dreams soar, young man. And if all you foresee were to come true, what then?"

"You would scarcely have time to run Aurora and the Robotics Institute, too. So I ask that when you finally decide to resign from your present position as the head of the Institute, you be prepared to support me as your successor to the post. You could scarcely expect to have your personal choice rejected."

Amadiro said, "There is such a thing as qualification for the post."

"I will qualify."

"Let us wait and see."

"I am willing to wait and see, but you will find that well before complete success is ours, you will wish to grant this request of mine. Please grow accustomed to the idea, therefore."

"All this before I hear a word," murmured Amadiro. "Well, you are a member of the Institute and I will strive to grow accustomed to your personal dream, but now let us have an end to preliminaries and tell me how you intend to destroy Earth."

Almost automatically, Amadiro made the sign that indicated to his robots that they were not to remember any part of the conversation. And Mandamus, with a small smile, did the same for his.

"Let us start then," said Mandamus.

But before he could speak further, Amadiro moved to the attack.

"Are you sure you're not pro-Earth?"

Mandamus looked startled. "I am coming to you with a proposal to destroy Earth."

"And yet you are a descendant of the Solarian woman in the fifth generation, I understand."

"Yes, sir, it is on public record. What of that?"

"The Solarian woman is, and has been for a long time, a close associate - friend - protegee - of Fastolfe. I wonder you do not sympathize with his pro-Earth views, therefore."

"Because of my ancestry?" Mandamus seemed honestly astonished. For a moment, what might have been a flash of annoyance or even anger seemed to tighten his nostrils, but that vanished and he said quietly, "An equally longtime close associate - friend - protegee - of your own is Dr. Vasilia Fastolfe, who is Dr. Fastolfe's daughter. She is a descendant in the first generation. I wonder she does not sympathize with his views."

"I have in the past also wondered," said Amadiro, "but she doesn't sympathize with them and, in her case, I have ceased wondering."

"You may cease wondering in my case, too, sir. I am a Spacer and I want to see the Spacers in control of the Galaxy."

"Very well, then. Go on with the description of your plan."

Mandamus said, "I will, but - if you don't mind - from the beginning.

"Dr. Amadiro, astronomers agree that there are millions of Earthlike planets in our Galaxy, planets on which human beings can live after necessary adjustments to the environment but without any need for geological terraforming. Their atmospheres are breathable, an ocean of water is present, the land and climate is suitable, life exists. Indeed, the atmospheres would not contain free oxygen without the presence of ocean plankton at the very least.

"The land is often barren, but once it and the ocean undergo biological terraforming - that is, once they are seeded with Earth life - such life flourishes and the planet can then be settled. Hundreds of such planets have been recorded and studied and about half of them are already occupied by Settlers.

"And yet not one habitable planet of all those which have been discovered to date has the enormous variety and excess of life that Earth has. Not one has anything larger or more complex than a small array of wormlike or insect like invertebrates or, in the plant world, anything more advanced than some fernlike shrubbery. No question of intelligence, of anything even approaching intelligence."

Amadiro listened to the stiff sentences and thought: He's speaking by rote. He's memorized all this. - He stirred and said, "I am not a planetologist, Dr. Mandamus, but I ask you to believe that you are telling me nothing I don't already know."

"As I said, Dr. Amadiro, I am starting from the beginning. - Astronomers are increasingly of the belief that we have a fair sample of the habitable planets of the Galaxy and that all - or almost all - are markedly different from Earth. For some reason, Earth is a surprisingly unusual Planet and evolution has proceeded on it at a radically rapid pace and m a radically abnormal manner."

Amadiro said, "The usual argument is that if there were another intelligent species in the Galaxy that was as advanced as we are, it would have become aware of our expansion by now and have made themselves known to us one way or another."

Mandamus said, "Yes, sir. In fact, if there were another intelligent species in the Galaxy that was more advanced than we are, we would not have had a chance to expand in the first place. That we are the only species in the Galaxy capable of traveling in hyperspace would seem certain, then. That we are the only species in the Galaxy that is intelligent is perhaps not quite certain, but there is a very good chance that we are."

Amadiro was now listening with a weary half-smile. The young man was being didactic, like a man stamping out the rhythm of his monomania in a dull beat. It was one of the marks of the crank and the mild hope Amadiro had had that Mandamus might actually have something that would turn the tide of history was beginning to fade.

He said, "You continue to tell me the known, Dr. Mandamus. Everyone knows Earth seems unique and that we are probably the only intelligent species in the Galaxy."

"But no one seems to ask the simple question: 'Why?' The Earthpeople and the Settlers don't ask it. They accept it. They have a mystic attitude toward Earth and consider it a holy world, so that its unusual nature is taken as a matter of course. As for the Spacers, we don't ask it. We ignore it. We do our best not to think of Earth at all, since if we do, we are liable to go further and think of ourselves as having descended from Earthpeople."

Amadiro said, "I see no virtue in the question. We need not seek for complex answers to the 'Why?' Random processes play an important role in evolution and, to some extent, in all things. If there are millions of habitable worlds, evolution may proceed on each of them at a different rate. On most, the rate will have some intermediate value; on some the rate will be distinctly slow, on others distinctly fast; on perhaps one it would proceed exceedingly slow and on another exceedingly fast. Earth happens to be the one on which it proceeded exceedingly fast and we are here because of that. Now if we ask 'Why?' the natural - and sufficient - answer is 'Chance.'"

Amadiro waited for the other to betray the crank by exploding in rage at a preeminently logical statement presented in an amused way, that served to shatter his thesis completely. Mandamus, however, merely stared at him for a few moments out of his deep-set eyes and then said quietly, "NO."

Mandamus let that stand for perhaps two beats and then said, "It takes more than a lucky chance or two to speed evolution a thousand fold. On every planet but Earth, the speed of evolution is closely related to the flux of cosmic radiation in which that planet is bathed. That speed is not the result of chance at all but the result of cosmic radiation producing mutations at a slow rate. On Earth, something produces many more mutations than are produced on other habitable planets and that has nothing to do with cosmic rays, for they do not strike Earth in any remarkable profusion. Perhaps you see a little more clearly, now, why the 'Why?' could be important."

"Well, then, Dr. Mandamus, since I am still listening, with rather more patience than I would have expected myself to possess, answer the question you so insistently raise. Or do you merely have the question and no answer?"

"I have an answer," said Mandamus, "and it depends upon the fact that Earth is unique in a second way."

Amadiro said, "Let me anticipate. You are referring to its large satellite. Surely, Dr. Mandamus, you are not advancing this as a discovery of yours."

"Not at all," said Mandamus stiffly, "but consider that large satellites seem to be common. Our planetary system has five, Earth's has seven and so on. All the known large satellites but one, however, circle gas giants. Only Earth's satellite, the moon, circles a planet not much larger than itself."

"Dare I use the word 'chance' again, Dr. Mandamus?"

"In this case, it may be chance, but the moon remains unique."

"Even so. What possible connection can the satellite have with Earth's profusion of life?"

"That may not be obvious and a connection may be unlikely - but it is far more unlikely that two such unusual examples of uniqueness in a single planet can have no connection at all. I have found such a connection."

"Indeed?" said Amadiro alertly. Now ought to come unmistakable evidence of crackpotism. He looked casually at the time strip on the wall. There really wasn't much more time he could possibly spend on this, for all that his curiosity continued to be aroused.

"The moon," said Mandamus, "is slowly receding from Earth, due to its tidal effect on the Earth. Earth's large tides are a unique consequence of the existence of this large satellite. Earth's sun produces tides, too, but to only a third of the extent of the moon's tides - just as our sun produces small tides on Aurora.

"Since the moon recedes because of its tidal action, it was far closer to Earth during the early history of its planetary system. The closer the moon to the Earth, the higher the tides on Earth. These tides had two important effects on Earth. It flexed the Earth's crust continually as the Earth rotated and it slowed the Earth's rotation, both through that flexing and through the friction of the ocean's water tides on shallow sea bottoms - so that rotational energy was converted to heat.

"The Earth, therefore, has a thinner crust than any other habitable planet we know of and it is the only habitable planet that displays volcanic action and that has a lively system of plate tectonics."

Amadiro said, "But even all this can have nothing to do with Earth's profusion of life. I think you must either get to the point, Dr. Mandamus, or leave."

"Please bear with me, Dr. Amadiro, for just a little while longer. It is important to understand the point once we get to it. I have made a careful computer simulation of the chemical development of Earth's crust, allowing for the effect of tidal action and plate tectonics, something that no one has ever done before in as meticulous and elaborate a way as I have managed to do - if I may praise myself."

"Oh, by all means," murmured Amadiro.

"And it turns out, quite clearly - I will show you all the necessary data at any time you wish - that uranium and thorium collect in Earth's crust and upper mantle in concentrations of up to a thousand times as high as in any other habitable world. Moreover, they collect unevenly, so that scattered over the Earth are occasional pockets where uranium and thorium are even more concentrated."

"And, I take it, dangerously high in radioactivity?"

"No, Dr. Amadiro. Uranium and thorium are very weakly radioactive and even where they are relatively concentrated, they are not very concentrated in an absolute sense. - All this, I repeat, is because of the presence of a large moon."

"I assume, then, that the radioactivity, even if not intense enough to be dangerous to life, does suffice to increase the mutation rate. Is that it, Dr. Mandamus?"

"That is it. There would be more rapid extinctions now and then, but also more rapid development of new species - resulting in an enormous variety and profusion of life-forms. And, eventually, on Earth alone, this would have reached the point of developing an intelligent species and a civilization."

Amadiro nodded. The young man was not a crank. He might be wrong, but he was not a crank. And he might be right, too -

Amadiro was not a planetologist, so he would have to check books on the subject to see whether Mandamus had perhaps discovered only the already-known, as so many enthusiasts did. There was, however, a more important point he had to check at once.

He said in a soft voice, "You've spoken of the possible destruction of Earth. Is there some connection between that and Earth's unique properties?"

"One can take advantage of unique properties in a unique manner," said Mandamus just as softly.

"In this particular case - in what way?"

"Before discussing the method, Dr. Amadiro, I must explain that, in one respect, the question as to whether destruction is physically possible depends on you."

"On me?"

"Yes," said Mandamus firmly. "On you. Why, otherwise, should I come to you with this long story if not to persuade you that I know what I'm talking about, so that you would be willing to cooperate with me in a manner that will be essential to my success?"

Amadiro drew a long breath. "And if I refused, would anyone else serve your purpose?"

"It might be possible for me to turn to others if you refuse. Do you refuse?"

"Perhaps not, but I am wondering how essential I am to you."

"The answer is, not quite as essential as I am to you. You must cooperate with me."

"Must?"

"I would like you to - if you prefer it phrased in that fashion. But if you wish Aurora and the Spacers to triumph, now and forever, over Earth and the Settlers, then you must cooperate with me, whether you like the phrase or not."

Amadiro said, "Tell me what it is, exactly, that I must do."

"Begin by telling me if it is not true that the Institute has, in the past, designed and constructed humanoid robots."

"Yes, we did. Fifty of them all together. That was between fifteen and twenty decades ago."

"That long ago? And what happened to them?"

"They failed," said Amadiro indifferently.

Mandamus sat back in his chair with a horrified expression on his face. "They were destroyed?"

Amadiro's eyebrows shot upward. "Destroyed? No one destroys expensive robots. They are in storage. The power units are removed and a special long-lived microfusion battery is in each to keep the positronic paths minimally alive."

"Then they can be brought back to full action?"

"I am sure they can."

Mandamus's right hand beat out a tightly controlled rhythm against the arm of the chair. He said grimly, "Then we can win!"