Dark as Day

22

In the early days of the Ligon corporate empire, the tradition was well-known if unspoken. The smartest of each generation ran the family business. The worthy but uninspired went into the church or military service, while the idiots with Cousin Hector’s combination of stupidity and furious energy would be tucked away on a remote part of the broad baronial estates where he could do little damage.

Alex stared out of the port and decided that the Ligon family had now adopted a new principle. Today, the fool of the family was sent off on a fruitless mission to a distant part of the solar system. There he was supposed to meet with a man who preferred to avoid everyone, and persuade him in a manner unspecified to share his lease on Pandora with the Ligon corporate interests.

Based on what he had seen so far, Alex found it hard to believe that a rational human would want any part of the Saturnian system. The sun was a feeble and shrunken disk of light, nothing like the radiant orb visible from Ganymede. As for the planet itself, guarded by its great ring system, Saturn gave an impression of cold, aloof mystery. When Great-aunt Cora had described Alex’s trip to Saturn as being to “the outback of the solar system,” Uncle Karolus had laughed and said, “More like the outhouse.” As for Alex’s final destination, which he was fast approaching, that was nothing at all — an insignificant mote of a world, forever unable to support an atmosphere, a gravity field, or a civilization.

The only moon of Saturn that any Ligon family member took seriously was Titan, today clouded by dense hydrocarbon fogs, but with long-term potential, according to the professional world-builders, that matched Ganymede and Callisto.

So what did Pandora, only minutes away, have to offer? Nothing but the old rule of real estate: location, location, location. It was well situated to operate as the nerve center for the swarming Von Neumanns who would mine the Saturnian atmosphere. More important yet, it commanded the access rights for that mining.

Which just made things tough for the present occupant, because in Alex’s experience, what Ligon wanted Ligon got. For instance, they wanted him here, and here he was. Kate had been confident that the work he was doing on the predictive model would persuade their superiors that he should remain on Ganymede. Her message of recommendation to that effect had gone all the way up to Magrit Knudsen — and bounced back down with a totally contrary command. Alex would not only go to Pandora and communicate with its mysterious occupant, he would explain his work on predictive models and the problems that they were encountering.

That seemed like an insult to both Kate and Alex. Kate had done some checking through her own network, and learned that the hermit who lived on Pandora had a reputation for gluttony and arrogance in roughly equal parts. The only reason for asking him anything was that he had once worked for Magrit Knudsen and apparently owed her some allegiance. Also, a few years ago he had sorted out — more by luck than anything else, according to his fellow-workers at the time — a major mystery on Europa.

Alex had been told to expect no greeting at Pandora’s single dock. He was to make his way from the surface, through multiple air-locks, and down a long elevator shaft. That was as far as the instructions took him. From that point he would be on his own.

Docking in the negligible gravity of Pandora took only a few minutes. Alex, about to leave his single-person ship, hesitated. On the journey from Ganymede he had spent his waking hours playing with the predictive model, making a variety of assumptions, plugging them in as exogenous variables, and studying the output. The ship’s computer had a Seine link, but one permitting only an infuriatingly low transfer data rate. Alex’s results had been more puzzling than persuasive.

However, he would hot leave them behind. He dismounted the data cube that contained both his program and his most recent results, and tucked them away in a side pocket of his travel bag. If Rustum Battachariya was, as Magrit Knudsen insisted, a computer specialist with considerable intellectual resources of his own, perhaps Alex might find a way to repeat his recent runs in a more forgiving computer setting.

The descent into Pandora’s gloomy interior did not affect Alex as it would have, say, Kate or his mother. He was not interested in the physical appearance of his surroundings — “blind as a worm,” according to Kate, when it came to niceties of furnishings. Had he been taking notice, he would have discovered one point at least on which he and the lone inhabitant of Pandora agreed: simplicity. The walls were bleak rock or dull plastic. Alex passed through the last of three massive sets of air-locks, removed his suit, and kept going.

At the end of the elevator shaft he had no options as to what to do next. A single corridor, forty meters long, ended in a steel door. The door was closed, but a red button stood in the center with a sign above it: AFTER THE BUTTON IS PRESSED, YOU WILL HAVE SEVEN SECONDS IN WHICH TO ENTER.

Alex pressed, drifted on through as the door opened, and wondered about the need for such security. So far as he could see there was nothing on or in Pandora that anyone in his right mind would think worth stealing. What it suggested was extreme paranoia on the part of the man he was about to meet.

Beyond the door Alex found himself at the side wall of a chamber that stretched far off to left and right. If the corridors and elevators he had seen so far were unusually empty, this room made up for them. It was packed — not with furniture, but with machines, all dust-free, gleaming, and placed relative to each other with great care. The only object out of place, in both its nature and its condition, stood about eight meters away on Alex’s left.

It was — Alex had to take a second look to make sure — a person; a man of colossal size, dressed in rumpled and tight-fitting black clothes, and with a black cowled hood that partly concealed his face.

The man nodded to Alex. He said, in a rumbling but precise voice, “I have observed your progress since the arrival of your ship at the surface. I must say that you arrive at a peculiarly inconvenient time.”

“For both of us,” Alex said.

He was ignored as the other went on, “I will not say welcome to Pandora, since that would be gross insincerity on my part. I will, however, ask if you have dined.”

Alex hadn’t eaten, nor did he particularly want to; but since this seemed like an unexpected attempt at politeness, he shook his head and said, “I didn’t eat.”

“Nor did I.” The other man threw back the cowl, to reveal a round shaven head. “I am, of course, Rustum Battachariya, and you of course are Alex Ligon. You may find it easier to call me Bat, though this should not be presumed to indicate any desire for a closeness of relationship between us. And when I invite you to share my afternoon repast, it is only because a failure to do so would display a churlish lack of civility and hospitality on my part.”

He led the way toward the far end of the room. Alex, who wondered if he had understood what the other was saying — it sounded, improbably, like he was inviting Alex to eat lunch — followed close behind. He could not help glancing from side to side as they went. The artifacts lining the walls or standing mounted on the floor formed a bizarre collection. None was new, many seemed from a much earlier generation of technology. Some bore the marks of fire, great force, or heavy impact.

Rustum Battachariya must have had eyes in the back of his head, because without turning he asked, “Are you perhaps interested in relics of the Great War?”

“Not particularly.” Alex actually had no interest at all in the Great War.

“Hmmph.”

They proceeded in silence to the end of the room, then around an opening in a wall partition that did not run all the way to the ceiling. It led into a kitchen as elaborate as any that Alex had ever seen. The equipment included pots and pans big enough to serve a dozen people, although only two chairs stood by the solidly-built table. As an additional feature — odd for any kitchen — a small communications center was built into the wall next to one of the chain. The display was turned on, but offered only white noise.

As they entered, as though greeting their arrival, the screen became a flickering mosaic of colors and a woman’s calm voice said, “Confirmation of the Masters’ conference call, to take place within one hour. The purpose is to finalize the Beston agreement with the Puzzle Network.”

Bat scowled. “Noted and accepted.” He saw Alex’s questioning look. “That channel is specifically for Puzzle Network interactions. Is it possible that you are interested in, or perhaps even a member of, the Puzzle Network?”

“No, I’m not a member.” Alex, convinced that another “Hmmph” was on its way, added, “I was very much into the Puzzle Network when I was younger, and I thought I had a chance to reach the Master level.”

“But you were unsuccessful?”

“Not exactly. My family didn’t think it was the sort of thing I should be interested in. My mother put a lot of pressure on me to give it up.”

“Ah. The problem of parents.” The round black head nodded. “I too had such difficulties, until we parted company when I was a teenager.”

“You left home?”

“To be rather more accurate, they threw me out. My parents, like yours, considered my level of interest in the Puzzle Network inordinate and inappropriate.” Bat waved a fat hand toward one of the chairs. “Please be seated. Few things in the universe must be delivered precisely on time, but a perfect souffle is one of them.”

Alex sat down with no great expectations. The other man could clearly put away a mountain of food, and from the look of him he often did, but quantity was no guide to quality. And Alex had eaten meals prepared by the best chefs in the System. Prosper Ligon had no interest in food, but the rest of the family insisted on the highest quality of cuisine.

Bat quickly produced from half a dozen different ovens a giant souffle, three different cooked vegetables, five sauces, and a loaf of bread which he sliced with amazing speed and dexterity. Alex filled his plate, began to eat, and after a few moments stared at his companion. He shook his head. “This is sensational. I think it’s the best food I’ve ever had.”

“Probably.” Bat was tasting carefully, a frown on his pudgy face. “It is better than average. I feel, however, that I was perhaps a trifle heavy-handed with the tarragon.”

Alex didn’t know if he was supposed to agree or disagree. He decided that it was safer to eat in silence. So far they had managed to agree on nothing except the problem of having parents. Rustum Battachariya also showed no inclination to conversation, eating steadily and thoughtfully and in quantities that established a need for outsized cooking utensils.

Finally Bat pushed away his plate, sighed, and said to Alex, “We have dined together, which will perhaps ensure a degree of civility in what follows. Or perhaps not. Let me be frank. I agreed to meet with you for one reason only: I was warned that should I refuse to do so, strong tactics might be used against me. Specifically, I was warned of physical violence or even murder. What is your reaction to such warnings?”

“They are absolute nonsense. I would never consider any sort of threat.”

“That is gratifying to hear. Are you confident that you speak for your whole family? If so, this meeting may be concluded at once, and we can return to our respective interests.”

Alex was on the spot. If he was confident of anything, it was that he could not speak for the whole family. At last he said, “I think it might be a good idea if you and I were to continue our discussion.”

“Very well. Let us do so. But I roust ask, on what basis? You would like me to give up or share my lease on Pandora. Why? And what inducements can you offer me, other than the not inconsiderable one that my life and physical well-being might otherwise be in jeopardy?”

“I have the authority to offer you a considerable amount of money, far more than the cost of your lease on Pandora.”

“Money?” Bat dismissed the word with a wave of his hand. “I happen to know that you work for the Outer System government, at a salary which is by the standards of your own family members ludicrously low. Am I supposed to believe that your own principal motive in life is money? If it is not, why should you assume that I am any different? Come, Mr. Ligon, if as a young man you approached Puzzle Network Master level, you cannot be without intelligence. Surely you can make an argument stronger than that?”

Greedy and arrogant seemed to be about right. Alex had watched Bat put away enough food for six people, and now the haughty part was showing through. Alex remembered Kate’s words. He’s so fat and obstinate you can’t push him. You have to mow him some other way.

Alex was saved from the need for immediate reply by the chime of the communications unit set in the wall by Bat’s left hand. The same woman’s voice said, “Conference will begin five minutes from now. Elect visual or voice-only mode.”

Bat said, “Voice only,” and then to Alex, “I may require privacy for a brief period. This is a matter of great practical significance.”

“That’s all right. I brought my programs and some recent results. I’ll have plenty to do — if you can provide computer access.”

“Of course. You may have access to the Seine, or if you prefer it you may use the Keep, which is my wholly internal and protected resource. If the latter—”

Bat’s next words were drowned out by a grating klaxon that sounded all through the Bat Cave. Alex felt a series of heavy vibrations, carried through the floor.

As the klaxon ended, the woman’s voice spoke again. “We are registering interference on all incoming communication channels. A foreign body which offers no identification is approaching Pandora and seeking forcible entrance. All external access has been sealed. Habitat separation of the Bat Cave from outside influences is complete.”

Alex saw Bat’s questioning glare and shook his head. “Not my doing. I have no idea what is happening.”

“No more than do I. The timing of this is extraordinarily inconvenient. Unless, of course, it was expressly designed to interfere with my planned activities; My conference call is minutes away. Who would attack Pandora, and why? This is not the best location to address those questions. Come.” Bat led the way, out of the kitchen and along the length of the Bat Cave.

Alex, following, understood Bat’s final remark when they reached the other end of the great rectangular chamber. The communications center in the kitchen had been small and primitive. The one they approached was as elaborate as anything controlled by Ligon Industries.

Bat plumped himself down on a massive padded chair. “We are, of course, in no danger of any kind. We are sealed and shielded, from both material and electromagnetic interference.” To Alex he seemed as much intrigued as annoyed as his fat fingers rippled over a console. “No ship in the solar system is capable of doing significant material damage to Pandora. Which leaves the question, who would want to come out here, jam all incoming signals, and try to blunder in? All system communications are monitored. A man would have to be an utter fool to imagine that such a situation could be maintained for any length of time, or that he and his vessel would not promptly be taken into custody.”

A man would have to be an utter fool…

Alex had no trouble thinking of a candidate. Hector! His cousin knew that the Ligon family wanted the current leaseholder out of Pandora. Lucy Mobarak had asked Hector to perform some great deed. Could his cousin be such an idiot as to think that threatening Rustum Battachariya on his home ground would qualify — at the very time when Alex himself was out here to negotiate?

Easily. It was exactly the kind of pea-brained action, with never a thought as to consequences or what he himself would do next, that Hector had specialized in since he was old enough to walk. The irritating thing was that his cousin seemed able to get away with it. Aunts and uncles said, “Oh, that was Hector. You know what Hector’s like…” and left it at that.

It wasn’t something that Alex could easily explain to anyone who was not part of the family. Instead, he said, “You mentioned that you feared aggressive action unless you came to some arrangement. Is the conference call that you’ll be missing connected with that?”

Bat finished running his fingers over the console. “We’re totally blacked out so far as incoming or outgoing signals is concerned,” he said. “No estimates as to how long it will last.” And then, “My conference call is on a different subject entirely. Have you been following the recent news leaks about alien messages?”

Aliens again! The word went into Alex like an electric shock. He’d had aliens on his mind for weeks. They formed part of some of the high-probability predicted futures, in strange and confusing ways. But Bat couldn’t possibly be referring to that.

Alex said cautiously, “Well, I’ve seen a blurt or two about alien messages. But you don’t believe what you hear on those.”

“Normally, you should not. In this case, however, the situation is rather different.” Bat composed himself on his chair. With head bowed forward and hands placed palms together in front of him, he reminded Alex of some ancient carved idol. Alex stood and fidgeted uncomfortably.

“I believe that I can divulge this to you without compromising confidentiality,” Bat said at last. “The time for the official news release is very close. Puzzle Network members, as you are surely aware, do not seek or enjoy the company of others. We do not cluster, we do not congregate, we rarely make group decisions. However, some years ago it was agreed by the Master level players of the Network that there might be one notable exception. The ultimate challenge as a puzzle would surely be the deciphering of a signal from an extraterrestrial intelligence. For such a thing, we would sacrifice privacy and anonymity. We would work together, we would even, if necessary, meet.”

“Here, in the Bat Cave?”

“I think not.” Bat’s expression revealed his repugnance at the thought. “This is — or was once, and should be — my private retreat.”

“But if you don’t meet here, you’d have to go somewhere else.”

“Your statement, although undeniably true, is hardly a triumph of abstract deductive thought.”

“Are you saying that the blurt is right — an alien message has really been received?”

“Your skepticism matches my own feelings when I first heard rumors over the blurt outlets. I generally dismiss as preposterous any claims of alien signals. That remained my position for several recent weeks, as confirmation of the blurt failed to appear. Four days ago, the situation changed radically. A group of high-level Masters of the Puzzle Network, of which I happen to be one, were contacted by a man named Philip Beston. He is head of the Odin Station at Jovian L-5. Beston asserted an alien signal has in truth been received — he forbore to call it a message, since no interpretation has as yet been performed. However, he did offer convincing evidence of both signal detection and verification. Moreover, he invited selected senior members of the Puzzle Network to join his group in a high-level collaborative effort, aimed at taking the first steps to transform a meaningless data stream signal to an intelligible message. As you might imagine, such an invitation proved irresistible. Network members normally work in isolation. Now, for the first time ever, we would pool findings and conjectures. The purpose of today’s conference call was merely to finalize a venue for that cooperative effort, since close proximity seems essential.”

“So you are going somewhere else.”

“Since I decline to convert the Bat Cave into a hotel for Puzzle Network Masters, that unfortunately appears to be the case.”

“Where?”

“I cannot be certain. However, the probabilities strongly favor Ganymede. It forms a home to more than half the Puzzle Masters.”

“I don’t believe this. I just came from Ganymede. You dragged me here, across half the solar system—”

Bat’s eyebrows rose high on his rounded forehead. “Excuse me? I dragged you? I dragged no one. Your presence was imposed on me, by extreme pressure from your family and a senior member of the Ganymede government.”

“You’re right. Forget I said that. I didn’t want to come, any more than you wanted me here. But why didn’t you tell me you might be on Ganymede in the near future?”

“For the best of all possible reasons. At the time when your journey began, I had no idea of any of this. I was still an extreme skeptic on the subject of SETI messages. By the time that my doubts were dispelled by Philip Beston’s call and accompanying evidence, you were already on the way.”

“I’m sorry.” Alex decided that blowing off steam at Bat would get neither of them anywhere. “I could have figured out the timing for myself. Assuming that you do go to Ganymede, how long will you be there?”

“I have no idea. Some weeks, or perhaps even months. The desire to be here, surrounded by the creature comforts and privacy of my own home, is very large. At the same time, suppose that we make significant progress in deciphering a message from the stars. That is probably unrealistic optimism, but how could one then resist staying, at least through the initial phase of discovery. It is a true case of Buridan’s famous ass.”

“I can see that.” Alex thanked whatever gods may be that he recognized the reference to Buridan’s donkey, starving to death because it was unable to choose between two equal bundles of hay. Cousin Hector would no doubt have said that he didn’t know this woman, Buridan, but from the sound of her he’d like to meet her.

But Alex saw a rare opportunity to come out a hero with his own family. “You are going to be away from Pandora for at least several weeks. In your absence, it would be easy for Ligon Industries to set up their operations center for helium-three mining from Saturn’s atmosphere at the other end of Pandora — so far away, you would never be aware of its presence. And the whole Starseed-Two project won’t be of long duration — it can’t be, without substantial penalty clauses. If we guaranteed that the installation would be done in your absence, with guarantees that nothing would affect the Bat Cave…”

Bat nodded, and for one moment Alex dared to hope they might have a deal. But then Bat said, “It is premature for any such discussion. I do not yet know where the Puzzle Masters will assemble, and already you have me off on Ganymede. Perhaps something can be arranged — if and when my own movements are more defined.” He waved a slab-like hand, dismissing the subject. “Enough of that speculation. I have explained to you the reason for my interest in aliens. What is the basis for your own? — I sensed more enthusiasm for that topic than for any other subject we have mentioned.”

Alex shook his head. “My interest is complicated and relates to my work on predictive models. It would take time and computer access to explain.”

“Time, apparently, is available in ample measure.” Bat waved his hand again, this time at the displays which showed all external communications still blocked. “Why are you interested in aliens? And why might the computers be relevant?”

Alex was hesitant at first. How much, if anything, did the other know of computer modeling? He began slowly, giving the sort of general explanation that would suffice for upper management, until Bat scowled and said, “Details, please, root and branch. Generality and vagueness are the refuge of scoundrels, politicians and bureaucrats.”

Put that way…

Alex began to describe his work at a deeper level, encouraged by Bat’s close attention and occasional nods. When he reached the tricky subject of the predicted extinction of humanity, and the dependence of that on exogenous variables, Bat blinked and nodded.

“I, too, have had intimations of approaching catastrophe throughout the solar system. The evidence I have seen is tenuous, but it suggests disaster much closer than a century away. Did your program take account of the possible effect of new weapons left over from the Great War?”

Alex shook his head. “I didn’t include them, because I have never heard of any such thing.”

“Very well. There are two other anomalous factors that you might wish to take into consideration. First, a small group of genetically modified humans was created as a by-product of the Great War. So far as I know, they live quiet and productive lives, but their possible impact on future events cannot be discounted.”

“I know about them, and I’ve run the model with and without their presence. The results do not changed significantly.”

“Very good. Then there was a group of humans of apparent great longevity, near-immortals who were active on Ganymede but vanished a generation ago. Nothing has been seen of them since, and it was conjectured that they chose to remove themselves to the far reaches of the outer system. However, they also might be significant to the future.”

Alex nodded. “I knew of them, too, and I ran the model both ways, with and without them. They also made no difference.”

“Then for the moment I have no other suggestions.” Bat glanced again at the display of blocked communications. “Let us return to the question of the effect of aliens. Can you describe how their presence affected your predictive model results?”

“I can do a lot better than describe.” Alex fumbled in his travel bag and produced the data cube. “I can show. Here are all the programs and the results. We can — oh, no, I guess we can’t. With access to outside communication blocked, we can’t get to the Seine. My models really suck up computer resources.”

“Such resources, fortunately, are available.” Bat looked smug. “Long before the Seine was activated, I foresaw dangers and difficulty in ensuring the privacy of my work. To be honest, one of my principal concerns was other members of the Puzzle Network. Cheating on a puzzle is by no means forbidden, including infiltration of another’s databases. For that reason I established an independent computer capability here on Pandora. I call it the Keep. It is fully disjoint from all aspects of the Seine, and I would be surprised if your model is unable to run on it.”

Alex was dubious. “When I said my model eats computer time and resources, I really meant it.”

Bat inclined his massive head. “I do not doubt you. I merely say, try, and see. One of us, I suspect, will be surprised.”

Bat had been referring to computer resources. Alex, as the runs proceeded, was astonished for quite other reasons.

The computer capacity available within the Keep was everything that Bat had suggested, with far more power than had been accessible to Alex prior to the arrival of the Seine. The predictive model ran fast, even at a high degree of detail. The cause of Alex’s amazement, however, lay elsewhere.

He began by repeating the series of runs in which an alien influence was assumed to be at work in the solar system, sometime in the next half century. He duplicated exactly the runs that he had already made, and was not surprised to find exactly comparable results.

“You see, everything remains stable,” he said to Bat. “No storage overflow, no solar system collapse, no end to humanity.”

“A comforting conclusion, since in that time frame we might reasonably hope to be present ourselves.”

“Right. But now see what happens when I make the same runs, and don’t introduce any alien influence as a variable.”

Again, it was an exact repeat of earlier runs that Alex had made. He sat back and waited for the instabilities to creep in, slowly at first and then catastrophically after half a century. He was so convinced of what he would see that he did not pay full attention to the results. Only when the time marker reached 2188, with a human population steadily growing and all variables within reasonable ranges, did he jerk up straight in his chair.

“That can’t be right!”

“No?” Bat had also been relaxing, watching the near-hypnotic march of numbers and graphics across the displays. He leaned forward, frowning. “Forgive me if I appear a little lacking in perception, but I fail to see any anomalies.”

“That’s what’s wrong with it.”

Bat, mysteriously, said, “The dog in the night?”

Alex ignored that and pointed to the year, now 2190, and the display of population, which was approaching twelve billion. “It never did that before. Without an alien influence as an exogenous variable, the model always reached a crisis point about 2140. Population never rose beyond a maximum value of ten billion.”

“There is a simple explanation.” Bat sounded unimpressed. “Either you had a problem with the model in your earlier runs, or you have one now.”

“You don’t understand. It’s the same model. I simply downloaded a copy before I left Ganymede. It must be your computer. It’s not powerful enough to run my model.”

“Never.” All signs of boredom in Bat vanished. “The Keep contains resources more powerful than any Ganymede facility.”

“You said you don’t have access to the Seine when you’re running in this mode.”

“That is true, but not relevant. If it is simply computer speed that concerns you, the computers in the Keep should be more” than adequate. Were you drawing on the Seine for other elements of the computation?”

“I’m sure I was. But I don’t see any way it could change the model results. Are you suggesting that the Seine itself might destabilize my predictive model results?”

“At first sight, I agree that sounds like a preposterous notion. But what do we really know of the Seine, and how it operates? Have you run your model sufficiently?”

“Sufficiently to confuse me totally.”

“Then with your permission, I will determine the external situation.” Bat touched half a dozen points on the console. “Hm. Incoming signals remain inaccessible. However, that is no bad thing… I must think…”

Bat closed his eyes and turned into an obsidian statue. Alex stared at the vast figure, motionless on the padded seat, and declined to interrupt. He had plenty to occupy his own mind. He turned his attention again to the display. It had advanced another twenty years. Every parameter showed reasonable values. According to his model, humanity was doing fine a hundred years from now.

The Seine as a factor? That raised a whole new series of questions. The Seine had access to every data bank in the System. It could and would use whatever information the model called for. But at the level of sophistication and complexity of the predictive model, there was no way that any human could hope to track the entirety of data in use — not even for one day of prediction, never mind a century.

So where did that leave Alex? He had stuck his neck way out, assuring everyone from Kate all the way up to Magrit Knudsen that with the Seine his predictive model would give correct results. All he needed was adequate computational power. But there was a built-in assumption: the only thing that the Seine was supposed to do was compute. The results of a model should not depend on the computer on which it was run. However, since the Seine also had the power to bring in System-wide data sets which the computer deemed relevant to the computation, then the exact reproduction of any results could not be guaranteed. What data might the Seine possess to indicate that a solar system future without alien presence was unstable and doomed to human extinction, while a future containing an alien presence was stable? And why did the Keep’s computer, aliens or no aliens, predict a future without a fatal collapse?

Alex was as capable of deep introspection as Bat. When a subdued beep came from the communication terminal, both men ignored it.

The beep came again, and again. At last an irate voice overrode the standard query signal and said, “Hello, Pandora. This is Atlas Station Security, calling Pandora. Are you receiving us? Hello, Pandora. Are you receiving this message?”

And then, in a fainter off-mike tone, “I think they’re all asleep or unconscious. I wonder if they even know they were jammed?”

Bat scowled, opened his eyes, and replied, “We are neither asleep nor unconscious. We are thinking — a phenomenon possibly outside your experience.”

“Oh, it’s you again. Well, you might think that a little appreciation would be in order for what we’ve done for you. We’ve arrested the wacko in the ship who was jamming your com lines.”

“Do you have an identification and a motive?”

“Not yet. He’s acting like a big hero and won’t say a word, and we don’t have a return yet for the ship’s I/D. It’s a Ganymede registration, though. Do you have anyone on Ganymede who dislikes you?”

“Numerous people.”

“Surprise, surprise. Do you have any idea who this one might be?”

Bat looked hard at Alex. “No.”

“Let us know if you want to press charges. We’ve got this fellow’s ship in tow, and we’re on our way. You have a waiting message stream whenever you decide to stop thinking. Au revoir, my ingrate friend.”

“He seems to know you rather well,” Alex said, then realized that might not be the most diplomatic of remarks.

Bat shrugged. “This is not my first encounter with the militants who call themselves the Atlas security force. Their main aim in life seems to be to protect me and the Bat Cave from physical assault, preferably by shooting at something. I have pointed out, many times, that this facility is more secure than their own base on Atlas. Although superficially rational, they appear incapable of learning this fact. No matter. Let us see what we missed in the past few hours.” He touched the console, and surveyed the list of incoming messages. “All of them can, I feel, wait — with the exception of this one.”

Another dab at the console. Three short sentences appeared on a small screen. Meeting place, Ganymede, Level 147, Sector 291. Individual work stations established. Start date pending schedule from Philip Beston.

Bat sighed. “As I thought. It will be necessary to leave the Bat Cave for awhile.”

“And go to Ganymede? Is that the message from the Puzzle Group?”

“It is. And almost certainly, Attoboy sent it. It bears his laconic trademark. I will decipher it later.”

“It seems straightforward enough.”

“It would not be from Attoboy if it lacked a hidden message within the clear text.”

“Maybe to tell you when the meeting begins?”

“I think not. I take his final sentence at face value.”

“Can we meet again when you arrive at Ganymede?”

That produced Bat’s longest hesitation so far. At last he said, “Your predictive model is new and intriguing, and it offers mysteries of inconsistency which so far I am unable to resolve. My instincts suggest that such a resolution could have far-reaching consequences. Certainly, this belongs on the four-sigma list.”

Bat paused, studying Alex as though the two men were just being introduced. The shaved black head nodded a few millimeters. “Before your arrival I had heard much about the Ligon family; all of it was, I am sorry to say, highly negative. You fail to fit my preconceptions. You have a genuine interest in and talent for intellectual problems. I would not find the prospect of another meeting, when I am on Ganymede, intolerable.”

One step at a time. Alex told himself that he had agreed to come here only because the family had pushed him, and he had never expected to succeed. Now when he returned to Ganymede he could report to Prosper Ligon and the others that, despite insane interference from Cousin Hector, he had made real progress. Rustum Battachariya had agreed to meet with Alex again — on Ganymede!

Magrit Knudsen was not there to provide Alex with a more striking evaluation of the situation. An agreement to meet again was the highest accolade that Bat ever offered to anyone. Alex had engaged Bat’s attention in the most powerful way possible: he had provided a puzzle too subtle and intricate to be solved at once.

In Bat’s upside-down universe, what could not be solved at once was not an annoyance; rather, in the best circumstances it would provide a source of ongoing pleasure and satisfaction for months or years to come.