14

Dr. Han Fastolfe was indeed waiting - and smiling. He was tall and thin, with light brown hair that was not very thick and there were, of course, his ears. It was the ears that Baley remembered, even after three years. Large ears, standing away from his head, giving him a vaguely humorous appearance, a pleasant homeliness. It was the ears that made Baley smile, rather than Fastolfe's welcome.

Baley wondered briefly if Auroran medical technology did not extend to the minor plastic surgery required to correct the ungainliness of those ears. - But then, it might well be that Fastolfe liked their appearance as Baley himself (rather to his surprise) did. There is something to be said about a face that makes one smile.

Perhaps Fastolfe valued being liked at first glance. Or was it that he found it useful to be underestimated? Or just different?

Fastolfe said, "Plainclothesman Elijah Baley. I remember you well, even though I persist in thinking of you as possessing the face of the actor who portrayed you."

Baley's face turned grim. "That hyperwave dramatization haunts me, Dr. Fastolfe. If I knew where I could go to escape - "

"Nowhere," said Fastolfe genially. "At least ordinarily. So if you don't like it, we'll expunge it from our conversations right now. I shall never mention it again. Agreed?"

"Thank you." With calculated suddenness, he thrust out his hand at Fastolfe.

Fastolfe hesitated perceptibly. Then he took Baley's hand, holding it gingerly - and not for long - and said, "I shall assume you are not a walking sack of infection, Mr. Baley."

Then he said ruefully, staring at his hands, "I must admit, though, that my hands have been treated with an inert - film that doesn't feel entirely comfortable. I'm a creature of the irrational fears of my society."

Baley shrugged. "So are we all. I do not relish the thought of being Outside - in the open air, that is. For that matter, I do not relish having had to come to Aurora under the circumstances in which I find myself."

"I understand that well, Mr. Baley. I have a closed car for you here and, when we come to my establishment, we will do our best to continue to keep you enclosed."

"Thank you, but in the course of my stay on Aurora, I feel that it will be necessary for me to stay Outside on occasion. I am prepared for that - as best I can be."

"I understand, but we will inflict the Outside on you only if it's necessary. That is not now the case so please consent to be enclosed."

The car was waiting in the shadow of the tunnel and there would scarcely be a trace of Outside in passing from the latter to the former. Behind him, Baley was aware of both Daneel and Giskard, quite dissimilar in appearance but both identical in grave and waiting attitude - and both endlessly patient.

Fastolfe opened the back door and said, "Please to get in."

Baley entered. Quickly and smoothly, Daneel entered behind him, while Giskard, virtually simultaneously, in what seemed almost like a well-choreographed dance movement, entered on the other side. Baley found himself wedged, but not oppressively so, between them. In fact, he welcomed the thought that, between himself and the Outside, on both sides, was the thickness of a robotic body.

But there was no Outside. Fastolfe climbed into the front seat and, as the door closed behind him, the windows blanked out, and a soft, artificial light suffused the interior.

Fastolfe said, "I don't generally drive this way, Mr. Baley, but I don't mind a great deal and you may find it more comfortable. The car is completely computerized, knows where it's going, and can deal with any obstructions or emergencies. We need interfere in no way."

There was the faintest feeling of acceleration and then a vague, barely noticeable sensation of motion.

Fastolfe said, "This is a secure passage, Mr. Baley. I have gone to considerable trouble to make certain that as few people as possible know you will be in this car and certainly you will not be detected within it. The trip by car - which rides on airjets, by the way, so that it is an airfoil, actually - will not take long, but, if you wish, you can seize the opportunity to rest. You are quite safe now."

"You speak," said Baley, "as though you think I'm in danger. I was protected to the point of imprisonment on the ship and again now." Baley looked about the small, enclosed interior of the car, within which he was hemmed by the frame of metal and opacified glass, to say nothing of the metallic frame of two robots.

Fastolfe laughed lightly. "I am overreacting, I know, but feeling runs high on Aurora. You arrive here at a time of crisis for us and I would rather be made to look silly by overreacting than to run the terrible risk that underreacting entails."

Baley said, "I believe you understand, Dr. Fastolfe, that my failure here would be a blow to Earth."

"I understand that well. I am as determined as you are to prevent your failure. Believe me."

"I do. Furthermore, my failure here, for whatever reason, will also be my personal and professional ruin on Earth."

Fastolfe turned in his seat to look at Baley with a shocked expression. "Really? That would not be warranted."

Baley shrugged. "I agree, but it will happen. I will be the obvious target for a desperate Earth government."

"This was not in my mind when I asked for you, Mr. Baley. You may be sure I will do what I can. Though, in all honesty" - his eyes fell away - "that will be little enough, if we lose."

"I know that," said Baley dourly. He leaned back against the soft upholstery and closed his eyes. The motion of the car was limited to a gentle lulling sway, but Baley did not sleep. Instead, he thought hard - for what that was worth.

15

Baley did not experience the Outside at the other end of the trip, either. When he emerged from the airfoil, he was in an underground garage and a small elevator brought him up to ground level (as it turned out).

He was ushered into a sunny room and, as he passed through the direct rays of the sun (yes, faintly orange), he shrank away a bit.

Fastolfe noticed. He said, "The windows are not opacifiable, though they can be darkened. I will do that, if you like. In fact, I should have thought of that - "

"No need," said Baley gruffly. "I'll just sit with my back to it. I must - acclimate myself."

"If you wish, but let me know if, at any time, you grow too uncomfortable. - Mr. Baley, it is late morning here on this part of Aurora. I don't know your personal time on the ship. If you have been awake for many hours and, would like to sleep, that can be arranged. If you are wakeful but not hungry you need not eat. However, if you feel you can manage it, you are welcome to have lunch with me in a short while."

"That would fit in well with my personal time, as it happens."

"Excellent. I'll remind you that our day is about seven percent shorter than Earth's. It shouldn't involve you in too much biorhythmic difficulty, but if it does, we will try to adjust ourselves to your needs."

"Thank you."

"Finally - I have no clear idea what your food preferences might be."

"I'll manage to eat whatever is put before me."

"Nevertheless, I won't feel offended if anything seems not palatable."

"Thank you."

"And you won't mind if Daneel and Giskard join us?"

Baley smiled faintly. "Will they be eating, too?"

There was no answering smile - from Fastolfe. He said seriously, "No, but I want them to be with you at all times."

"Still danger? Even here?"

"I trust nothing entirely. Even here."

A robot entered. "Sir, lunch is served."

Fastolfe nodded. "Very good, Faber. We will be at the table in a few moments."

Baley said, "How many robots do you have?"

"Quite a few. We are not at the Solarian level of ten thousand robots to a human being, but I have more than the average number - fifty-seven. The house is a large one and it serves as my office and my workshop as well. Then, too, my wife, when I have one, must have space, enough to be insulated from my work in a separate wing and must be served independently."

"Well, with fifty-seven robots, I imagine you can spare two. I feel the less guilty at your having sent Giskard and Daneel to escort me to Aurora."

"It was no casual choice, I assure you, Mr. Baley. Giskard is my majordomo and my right hand. He has been with me all my adult life."

"Yet you sent him on the trip to get me. I am honored," said Baley.

"It is a measure of your importance, Mr. Baley. Giskard is the most reliable of my robots, strong and sturdy."

Baley's eyes flickered toward Daneel and Fastolfe added, "I don't include my friend Daneel in these calculations. He is not my servant, but an achievement of which I have the weakness to be extremely proud. He is the first of his class and, while Dr. Roj Nemennuh Sarton was his designer and model, the man who - "

He paused delicately, but Baley nodded brusquely and said, "I understand."

He did not require the phrase to be completed with a reference to Sarton's murder on Earth.

"While Sarton supervised the actual construction," Fastolfe went on, "it was I whose theoretical calculations made Daneel possible,"

Fastolfe smiled at Daneel, who bowed his head in acknowledgment.

Baley said, "There was Jander, too."

"Yes." Fastolfe shook his head and looked downcast. "I should perhaps have kept him with me, as I do Daneel. But he was my second humaniform and that makes a difference. It is Daneel who is my first-born, so to speak - a special case."

"And you construct no more humaniform robots now?"

"No more. But come," said Fastolfe, rubbing his hands. "We must have our lunch. I do not think, Mr. Baley, that on Earth the population is accustomed to what I might term natural food. We are having shrimp salad, together with bread and cheese, milk, if you wish, or any of an assortment of fruit juices. It's all very simple. Ice cream for dessert."

"All traditional Earth dishes," said Baley, "which exist now in their original form only in Earth's ancient literature."

"None of it is entirely common here on Aurora, but I didn't think it made sense to subject you to our own version of gourmet dining, which involves food items and spices of Auroran varieties. The taste would have to be acquired."

He rose. "Please come with me, Mr. Baley. There will just be the two of us and we will not stand on ceremony or indulge in unnecessary dining ritual."

"Thank you," said Baley. "I accept that as a kindness. I have relieved the tedium of the trip here by a rather intensive viewing of material relating to Aurora and I know that proper politeness requires many aspects to a ceremonial meal that I would dread."

"You need not dread."

Baley said, "Could we break ceremony even to the extent of talking business over the meal, Dr. Fastolfe? I must not lose time unnecessarily."

"I sympathize with that point of view. We will indeed talk business and I imagine I can rely on you to say nothing to anyone concerning that lapse. I would not want to be expelled from polite society." He chuckled, then said, "Though I should not laugh. It is nothing to laugh at. Losing time may be more than an inconvenience alone. It could easily be fatal."

16

The room that Baley left was a spare one: several chairs, a chest of drawers, something that looked like a piano but had brass valves in the place of keys, some abstract designs on the walls that seemed to shimmer with light. The floor was a smooth checkerboard of several shades of brown, perhaps designed to be reminiscent of wood, and although it shone with highlights as though freshly waxed, it did not feel slippery underfoot.

The dining room, though it had the same floor, was like it in no other way. It was a long rectangular room, overburdened with decoration. It contained six large square tables that were clearly modules that could be assembled in various fashions. A bar was to be found along one short wall, with gleaming bottles of various colors standing before a curved mirror that seemed to lend a nearly infinite extension to the room it reflected. Along the other short wall were four recesses, in each of which a robot waited.

Both long walls were mosaics, in which the color's slowly changed. One was a planetary scene, though Baley could not tell if it were Aurora, or another planet, or something completely imaginary. At one end there was a wheat field (or something of that sort) filled with elaborate farm machinery, all robot-controlled. As one's eye traveled along the length of the wall, that gave way to scattered human habitations, be coming, at the other end, what Baley felt to be the Auroran version of a City.

The other long wall was astronomical. A planet, blue-white, lit by a distant sun, reflected light in such a manner that not the closest examination could free one from the thought that it was slowly rotating. The stars that surrounded, it - some faint, some bright - seemed also to be changing their patterns, though when the eye concentrated on some small grouping and remained fixed there, the stars seemed immobile.

Baley found it all confusing and repellent.

Fastolfe said, "Rather a work of art, Mr. Baley. Far too expensive to be worth it, though, but Fanya would have it. Fanya is my current partner."

"Will she be joining us, Dr. Fastolfe?"

"No, Mr. Baley. As I said, just the two of us. For the duration, I have asked her to remain in her own quarters. I do not want to subject her to this problem we have. You understand, I hope?"

"Yes, of course."

"Come. Please take your seat."

One of the tables was set with dishes, cups, and elaborate cutlery, not all of which were familiar to Baley. In the center was a tall, somewhat tapering cylinder that looked as though it might be a gigantic chess pawn made out of a gray rocky material.

Baley, as he sat down, could not resist reaching toward it and touching it with a finger.

Fastolfe smiled, "It's a spicer. It possesses simple controls that allows one to use it to deliver a fixed amount of any of a dozen different condiments on any portion of a dish. To do it properly, one picks it up and performs rather intricate evolutions that are meaningless in themselves but that are much valued by fashionable Aurorans as symbols of the grace and delicacy with which meals should be served. When I was younger, I could, with my thumb and two fingers, do the triple genuflection and produce salt as the spicer struck my palm. Now if I tried it, I'd run a good risk of braining my guest. I bust you won't mind if I do not try."

"I urge you not to try, Dr. Fastolfe."

A robot placed the salad on the table, another brought a tray of fruit juices, a third brought the bread and cheese, a fourth adjusted the napkins. All four operated in close coordination, weaving in and out without collision or any sign of difficulty. Baley watched them in astonishment.

They ended, without any apparent sign of prearrangements, one at each side of the table. They stepped back in unison, bowed in unison, turned in unison, and returned to the recesses along the wall at the far end of the room. Baley was suddenly aware of Daneel and Giskard in the room as well. He had not seen them come in. They waited in two recesses that had somehow appeared along the wall with the wheat-field. Daneel was the closer.

Fastolfe said, "Now that they've gone - " He paused and shook his head slowly in rueful conclusion. "Except that they haven't. Ordinarily, it is customary for the robots to leave before lunch actually begins. Robots do not eat, while human beings do. It therefore makes sense that those who eat do so and that those who do not leave. And it has ended by becoming one more, ritual. It would be quite unthinkable to eat until the robots left. In this case, though - "

"They have not left," said Baley.

"No. I felt that security came before etiquette and I felt that, not being an Auroran, you would not mind."

Baley waited for Fastolfe to make the first move. Fastolfe lifted a fork, so did Baley. Fastolfe made use of it, moving slowly and allowing Baley to see exactly what he was doing.

Baley bit cautiously into a shrimp and found it delightful. He recognized the taste, which was like the shrimp paste produced on Earth but enormously more subtle and rich. He chewed slowly and, for a while, despite his anxiety to get on with the investigation while dining, he found it quite unthinkable to do anything but give his full attention to the lunch.

It was in fact, Fastolfe who made the first move. "Shouldn't we make a beginning on the problem, Mr. Baley?"

Baley felt himself flush slightly. "Yes. By all means. I ask your pardon. Your Auroran food caught me by surprise, so that it was difficult for me to think of anything else. - The problem, Dr. Fastolfe, is of your making, isn't it?"

"Why do you say that?"

"Someone has committed roboticide in a manner that requires great expertise - as I have been told."

"Roboticide? An amusing term." Fastolfe smiled. "Of course, I understand what you mean by it. - You have been told correctly; the manner requires enormous expertise."

"And only you have the expertise to carry it out - as I have been told."

"You have been told correctly there, too."

"And even you yourself admit - in fact, you insist - that only you could have put Jander into a mental freeze-out."

"I maintain what is, after all, the truth, Mr. Baley. It would do me no good to lie, even if I could bring myself to do so. It is notorious that I am the outstanding theoretical roboticist in all the Fifty Worlds."

"Nevertheless, Dr. Fastolfe, might not the second-best theoretical roboticist in all the worlds - or the third-best, or even the fifteenth-best - nevertheless possess the necessary ability to commit the deed? Does it really require all the ability of the very best?"

Fastolfe said calmly, "In my opinion, it really requires all the ability of the very best. Indeed... I again in MY opinion, myself, could only accomplish the task on one of my good days. Remember that the best brains in robotics - including mine - have specifically labored to design, positronic brains that could not be driven into mental freeze-out."

"Are you certain of all that? Really certain?"

"Completely."

"And you stated so publicly?"

"Of course. There was a public inquiry, my dear Earthman. I was asked the questions you are now asking and I answered truthfully. It is an Auroran custom to do so."

Baley said, "I do not, at the moment, question that you were convinced, you were answering truthfully. But might you not have been swayed by a natural pride in yourself that might also be typically Auroran, might it not?"

"You mean that my anxiety to be considered the best would make me willingly put myself in a position where everyone would be forced to conclude I had mentally frozen Jander?"

"I picture you, somehow, as content to have your political and social status destroyed, provided your scientific reputation remained intact."

"I see. You have an interesting way of thinking, Mr. Baley. This would not have occurred to me. Given a choice between admitting I was second-best and admitting I was guilty of, to use your phrase, a roboticide, you are of the opinion I would knowingly accept the latter."

"No, I Dr. Fastolfe, I do not wish to present the matter quite so simplistically. Might it not be that you deceive yourself into thinking you are the greatest of all roboticists and that you are completely unrivaled, clinging to that at all costs, because you unconsciously - unconsciously, Dr. Fastolfe - realize that, in fact, you are, being overtaken - or have even already been overtaken - by others."

Fastolfe laughed, but there was an edge of annoyance in it. "Not so, Mr. Baley. Quite wrong."

"Think, Dr. Fastolfe! Are you certain that none of your roboticist colleagues can approach you in brilliance?"

"There are only a few who are capable of dealing at all with humaniform robots. Daneel's construction created virtually a new profession for which there is not even a name - humaniformicists, perhaps. Of the theoretical roboticists on Aurora, not one, except for myself, understands the workings of Daneel's positronic brain. Dr. Sarton did, but he is dead - and he did not understand it as well as I do. The basic theory is mine."

"It may have been yours to be in with, but surely you can't expect to maintain exclusive ownership. Has no one learned the theory?"

Fastolfe shook his head firmly. "Not one. I have taught no one and I defy any other living roboticist to have developed the theory on his own."

Baley said, with a touch of irritation, "Might there not be a bright young man, fresh out of the university, who is cleverer than anyone yet realizes, who - "

"No, Mr. Baley, no. I would have known such a young man. He would have passed through my laboratories. He would have worked with me. At the moment, no such young man exists. Eventually, one will; perhaps many will. At the moment, none!"

"If you died, then, the new science dies with you?"

"I am only a hundred and sixty-five years old. That's metric years, of course, so it I is only a hundred and twenty-four of your Earth years, more or less. I am still quite young by Auroran standards and there is no medical reason why my life should be considered even half over. It is not entirely unusual to reach an age of four hundred years - metric years. There is yet plenty of time to teach."

They had finished eating, but neither man made any move to leave the table. Nor did any robot approach to clear it. It was as though they were transfixed into immobility by the intensity of the back and forth flow of talk.

Baley's eyes narrowed. He said, "Dr. Fastolfe, two years ago I was on Solaria. There I was given the clear impression that the Solarians, were, on the whole, the most skilled roboticists in all the worlds."

"On the whole, that's probably true."

"And not one of them could have done the deed?"

"Not one, Mr. Baley. Their skill is with robots who are, at best, no more advanced than my poor, reliable Giskard. The Solarians know nothing of the construction of humaniform robots.

"How can you be sure of that?"

"Since you were on Solaria, Mr. Baley, you know very well that Solarians can approach each other with only the greatest of difficulty, that they interact by trimensional viewing - except where sexual contact is absolutely required. Do you think that any of them would dream of designing a robot so human in appearance that it would activate their neuroses? They would so avoid the possibility of approaching him, since he would look so human, that they could make no reasonable use of him."

"Might not a Solarian here or there display a surprising tolerance for the human body? How can you be sure?"

"Even if a Solarian could, which I do not deny, there are no Solarian nationals on Aurora this year."

"None?"

"None! They do not like to be thrown into contact even with Aurorans and, except on the most urgent business, none will come here - or to any other world. Even in the case of urgent business, they will come no closer than orbit and then they deal with us only by electronic communication."

Baley said, "In that case, if you are - literally and actually - the only person in all the worlds who could have done it, did you kill Jander?"

Fastolfe said, "I cannot believe that Daneel did not tell you I have denied this deed."

"He did tell me so, but I want to hear it from you."

Fastolfe crossed his arms and frowned. He said, through clenched teeth, "Then I'll tell you so. I did not do it."

Baley shook his head. "I believe you believe that statement."

"I do. And most sincerely. I am telling the truth. I did not kill Jander."

"But if you did not do it, and if no one, - else can possibly have done it, then - But wait. I am, perhaps, making an unwarranted assumption. Is Jander really dead or have I been brought here under false pretenses?"

"The robot is really destroyed. It will be quite possible to show him to you, if the Legislature does not bar my access to him before the day is over - which I don't think they will do."

"In that case, if you did not do it, and if no one else could possibly have done it, and if the robot is actually dead - who committed the crime?"

Fastolfe sighed. "I'm sure Daneel told you what I have maintained at the inquiry - but you want to hear it from my own lips."

"That is right, Dr. Fastolfe."

"Well, then, no one committed the crime. It was a spontaneous event in the positronic flow along the brain paths that set up the mental freeze-out in Jander."

"Is that likely?"

"No, it is not. It is extremely unlikely - but if I did not do it, then that is the only thing that can have happened."

"Might it not be argued that there is a greater chance that you are lying than that a spontaneous mental freeze-out took place."

"Many do so argue. But I happen to know that I did not do it and that leaves only the spontaneous event as a possibility."

"And you have had me brought here to demonstrate - to prove - that the spontaneous event did, - in fact, take place?"

"Yes."

"But how does one go about proving the spontaneous event? Only by proving it, it seems, can I save you, Earth, and myself."

"In order of increasing importance, Mr. Baley?"

Baley looked annoyed. "Well, then, you, me, and Earth."

"I'm afraid," said Fastolfe, "that after considerable thought, I have come to the conclusion that there is no way of obtaining such a proof."

17

Baley stared at Fastolfe in horror. "No way?"

"No way. None." And then, in a sudden fit of apparent abstraction, he seized the spicer and said, "You know, I am curious to see if I can still do the triple genuflection."

He tossed the spicer into the air with a calculated flip of the wrist. It somersaulted and, as it came down, Fastolfe caught the narrow end on the side of his right palm (his thumb tucked down). It went up slightly and swayed and was caught on the side of the left palm. It went up again in reverse and was caught on the side of the right palm and then again on the left palm. After this third genuflection, it was lifted with sufficient force to produce a flip. Fastolfe caught it in his right fist, with his left hand nearby, palm upward. Once the spicer was caught, Fastolfe displayed his left hand and there was a fine sprinkling of salt in it.

Fastolfe said, "It is a childish display to the scientific mind and the effort is totally disproportionate to the end, which is, of course, a pinch of salt, but the good Auroran host is proud of being able to put on a display. There are some experts who can keep the spicer in the air for a minute and a half, moving their hands almost more rapidly than the eye can follow.

"Of course," he added thoughtfully, "Daneel can perform such actions with greater skill and speed than any human. I have tested him in this manner in order to check on the workings of his brain paths, but it would be totally wrong to have him display such talents in public. It would needlessly humiliate human spicists - a popular term for them, you understand, though you won't find it in dictionaries."

Baley grunted.

Fastolfe sighed. "But we must get back to business."

"You brought me through several parsecs of space for that purpose,"

"Indeed, I did. - Let us proceed!"

Baley said, "Was there a reason for that display of yours, Dr. Fastolfe?"

Fastolfe said, "Well, we seem to have come to an impasse. I've brought you here to do something that can't be done. Your face was rather eloquent and, to tell you the truth, I felt no better. It seemed, therefore, that we could use a breathing space. And now - let us proceed."

"On the impossible task?"

"Why should it be impossible for you, Mr. Baley? Your reputation is that of an achiever of the impossible."

"The hyperwave drama? You believe that foolish distortion of what happened on Solaria?"

Fastolfe spread his arms. "I have no other hope."

Baley said, "And I have no choice. I must continue to try; I cannot return to Earth a failure. That has been made clear to me. - Tell me, Dr. Fastolfe, how could Jander have been killed? What sort of manipulation of his mind would have been required?"

"Mr. Baley don't know how I could possibly explain that, even to another roboticist, which you certainly are not, and even if I were prepared to publish my theories, which I certainly am not. However, let me see if I can't explain something. - You know, of course, that robots were invented on Earth."

"Very little concerning robotics is dealt with on Earth - "

"Earth's strong antirobot bias is well-known on the Spacer worlds. But the Earthly origin of robots is obvious to any person on Earth who thinks about it. It is well-known that hyperspatial travel was developed with the aid of robots and, since the Spacer worlds could not have been settled without hyperspatial travel, it follows that robots existed before settlement had taken place and while Earth was still the only inhabited planet. Robots were therefore invented on Earth by Earthpeople."

"Yet Earth feels no pride in that, does it?"

"We do not discuss it," said Baley shortly.

"And Eartlipeople know nothing about Susan Calvin?"

"I have come across her name in a few old books. She was one of the early pioneers in robotics."

"Is that all you know of her?"

Baley made a gesture of dismissal. "I suppose I could find out more if I searched the records, but I have had no occasion to do so."

"How strange," said Fastolfe. "She's a demigod to all Spacers, so much so that I imagine that few Spacers who are not actually roboticists think of her as an Earthwoman. It would seem a profanation. They would refuse to believe it if they were told that she died after having lived scarcely more than a hundred metric years. And yet you know her only as an early pioneer."

"Has she got something to do with all this, Dr. Fastolfe?"

"Not directly, but in a way. You must understand that numerous legends cluster about her name. Most of them are undoubtedly untrue, but they cling to her, nonetheless. One of the most famous legends - and one of the least likely to be true  -  concerns a robot manufactured in those primitive days that, through some accident on the production lines, turned out to have telepathic abilities - "

"What!"

"A legend! I told you it was a legend - and undoubtedly untrue! Mind you, there is some theoretical reason for supposing this might be possible, though no one has ever presented a plausible design, that could even begin to incorporate such an ability. That it could have appeared in positronic brains as crude and simple as those in the prehyperspatial era is totally unthinkable. That is why we are quite certain that this particular tale is an invention. But let me go on anyway, for it points out a moral.

"By all means, go on."

"The robot, according to the tale, could read minds. And when asked questions, he read the questioner's mind and told the questioner what he wanted to hear. Now the First Law of Robotics states quite clearly that a robot may not injure a human being or, through inaction, allow a person to come to harm, but to robots generally that means physical harm. A robot who can read minds, however, would surely decide that disappointment or anger or any violent emotion would make the human being feeling those emotions unhappy and, the robot would interpret the inspiring of such emotions under the heading of 'harm.' If, then, a telepathic robot knew that the truth might disappoint or enrage a questioner or cause that person to feel envy or unhappiness, he would tell a pleasing lie, instead. Do you see that?"

"Yes, of course."

"So the robot lied even to Susan Calvin herself. The lies could not long continue, for different people were told different things that were not only inconsistent among themselves but unsupported by the gathering evidence of reality, you see. Susan Calvin discovered she had been lied to and realized that those lies had led her into a position of considerable embarrassment. What would have disappointed her somewhat to begin with had now, thanks to false hopes, disappointed her unbearably. - You never heard the story?"

"I give you my word."

"Astonishing! Yet it certainly wasn't invented on Aurora, for it is equally current on all the worlds. - In any case, Calvin took her revenge. She pointed out to the robot that, whether he told the truth or told a lie, he would equally harm the person with whom he dealt. He could not obey the First Law, whatever action he took. The robot, understanding this, was forced to take refuge in total inaction. If you want to put it colorfully, his positronic pathways burned out. His brain was irrecoverably destroyed. The legend goes on, to say that Calvin's last word to the destroyed robot was 'Liar!'"

Baley said, "And something like this, I take it, was what happened to Jander Panell. He was faced with a contradiction in terms and his brain burned out?"

"It's what appears to have happened, though that is not as easy to bring about as it would have been in Susan Calvin's day. Possibly because of the legend, roboticists have always been careful to make it as difficult as possible for contradictions to arise. As the theory of positronic brains has grown more subtle and as the practice of positronic brain design has grown more intricate, increasingly successful systems have been devised to have all situations that might arise resolve into nonequality, so that some action can always be taken that will be interpreted as obeying the First Law."

"Well, then, you can't bum out a robot's brain. Is that what you're saying? Because if you are, what happened to Jander?"

"It's not what I'm saying. The increasingly successful systems I speak of are never completely successful. They cannot be. No matter how subtle and intricate a brain might be, there is always some way of setting up a contradiction. That is a fundamental truth of mathematics. It will remain forever impossible to produce a brain so subtle and intricate as to reduce the chance of contradiction to zero. Never quite to zero. However, the systems have been made so close to zero that to bring about a mental freeze-out by setting up a suitable contradiction would require a deep understanding of the particular positionic brain being dealt with - and that would take a clever theoretician."

"Such as yourself, Dr. Fastolfe?"

"Such as myself. In the case of humaniform robots, only myself."

"Or no one at all," said Baley, heavily ironic.

"Or no one at all. Precisely," said Fastolfe, ignoring the irony. "The humaniform robots have brains - and, I might add, bodies - constructed in conscious imitation of the human being. The positronic brains are extraordinarily delicate and they take on some of the fragility of the human brain, naturally. Just as a human being may have a stroke, though some chance event within the brain - and without the intervention of any external effect, so a humaniform brain might, through chance alone the occasional aimless drifting of positrons - go into mental - "

"Can you prove that, Dr. Fastolfe?"

"I can demonstrate it mathematically, but of those who could follow the mathematics, not all would agree that the reasoning was valid. It involves certain suppositions of my own that do not fit into the accepted modes of thinking in robotics."

"And how likely is spontaneous mental freeze-out?"

"Given a large number of humaniform robots, say a hundred thousand, there is an even chance that one of them might undergo spontaneous mental freeze-out in an average Auroran lifetime. And yet it could happen much sooner, as it did to Jander, although then the odds would be very greatly against it."

"But look here, Dr. Fastolfe, even if you were to prove conclusively that a spontaneous mental freeze-out could take place in robots generally, that would not be the same as proving that such a thing happened to Jander in particular at this particular time."

"No," admitted Fastolfe, "you are quite right."

"You, the greatest expert in robotics, cannot prove it in the specific case of Jander."

"Again, you are quite right."

"Then what do you expect me to be able to do, when I know I nothing of robotics."

"There is no need to prove anything. It would surely be sufficient to present an ingenious suggestion that would make spontaneous mental freeze-out plausible to the general public."

"Such as - "

"I don't know."

Baley said harshly. "Are you sure you don't know, Dr. Fastolfe?"

"What do you mean? I have just said I don't know."

"Let me point out something. I assume that Aurorans, generally, know that I have come to the planet for the purpose of tackling this problem. It would be difficult to manage to get me here secretly, considering that I am an Earthman and this is Aurora."

"Yes, certainly, and I made no attempt to do that. I consulted the Chairman of the Legislature and persuaded him to grant me permission to bring you here. It is how I've managed to win a stay in judgment. You are to be given a chance to solve the mystery before I go on trial. I doubt that they'll give me a very long stay."

"I repeat, then - Aurorans, in general, know I'm here and I imagine they know precisely why I am here - that I am supposed to solve the puzzle of the death of Jander."

"Of course. What other reason could there be?"

"And from the time I boarded the ship that brought me here, you have kept me under close and constant guard because of the danger that your enemies might try to eliminate me judging me to be some sort of wonderman who just might solve the puzzle in such a way as to place you on the winning side, even though all the odds are against me."

"I fear that as a possibility, yes."

"And suppose someone who does not want to see the puzzle solved and you, Dr. Fastolfe, exonerated should actually succeed in killing me. Might that not swing sentiment in your favor? Might not people reason that your enemies felt you were, in actual fact, innocent or they would not fear the investigation so much that they would want to kill me?"

"Rather complicated reasoning, Mr. Baley. I suppose that, properly exploited your death might be used to such a purpose, but it's not going happen. You are being protected and you will not be killed."

"But why protect me, Dr. Fastolfe? Why not let them kill me and use my death as a way of winning?"

"Because I would rather you remained alive and succeeded in actually demonstrating my innocence."

Baley said, "But surely you know that I can't demonstrate your innocence."

"Perhaps you can. You have every incentive. The welfare of Earth hangs on your doing so and, as you have told me, your own career."

"What good is incentive? If you ordered me to fly by flapping my arms and told me further that if I failed, I would be promptly killed by slow torture and that Earth would be blown up and all its population destroyed, I would have enormous incentive to flap my wings and fly - and yet still be unable to do so."

Fastolfe said uneasily, "I know, the chances are small."

"You know they are nonexistent," said Baley violently, "and that only my death can save you."

"Then I will not be saved, for I am seeing to it that my enemies cannot reach you."

"But you can reach me."

"What?"

"I have the thought in my head, Dr. Fastolfe, that you yourself might kill me in such a way as to make it appear that your enemies have done the deed. You would then use my death against them - and that that is why you have brought me to Aurora."

For a moment, Fastolfe looked at Baley with a kind of mild surprise and then, in an excess of passion both sudden and extreme, his face reddened and twisted into a snarl. Sweeping up the spicer from the table, he raised it high and brought his arm down to hurl it at Baley.

And Baley, caught utterly by surprise, barely managed to cringe back against his chair.