31 – Nursery

   MISS PRINGLE RECORD
   Well, Indra – Dim – I hope that came through in good shape – I still find it hard to believe. All those fantastic creatures – surely we should have detected their radio voices, even if we couldn't understand them! – wiped out in a moment, so that Jupiter could be made into a sun.
   And now we can understand why. It was to give the Europs their chance. What pitiless logic: is intelligence the only thing that matters? I can see some long arguments with Ted Khan over this – The next question is: will the Europs make the grade – or will they remain forever stuck in the kindergarten – not even that – the nursery? Though a thousand years is a very short time, one would have expected some progress, but according to Dave they're exactly the same now as when they left the sea. Perhaps that's the trouble; they still have one foot – or one twig! – in the water.
   And here's another thing we got completely wrong. We thought they went back into the water to sleep. It's just the other way round – they go back to eat, and sleep when they come on land! As we might have guessed from their structure – that network of branches – they're plankton feeders...
   I asked Dave about the igloos they've built. Aren't they a technological advance? And he said: not really – they're only adaptations of structures they make on the sea-bed, to protect themselves from various predators – especially something like a flying carpet, as big as a football field...
   There's one area, though, where they have shown initiative – even creativity. They're fascinated by metals, presumably because they don't exist in pure form in the ocean. That's why Tsien was stripped – the same thing's happened to the occasional probes that have come down in their territory. What do they do with the copper and beryllium and titanium they collect? Nothing useful, I'm afraid. They pile it all together in one place, in a fantastic heap that they keep reassembling. They could be developing an aesthetic sense – I've seen worse in the Museum of Modem Art... But I've got another theory – did you ever hear of cargo cults? During the twentieth century, some of the few primitive tribes that still existed made imitation aeroplanes out of bamboo, in the hope of attracting the big birds in the sky that occasionally brought them wonderful gifts. Perhaps the Europs have the same idea.
   Now that question you keep asking me... What is Dave? And how did he – and Hal – become whatever it is they are now?
   The quick answer, of course, is that they're both emulations – simulations – in the Monolith's gigantic memory. Most of the time they're inactivated; when I asked Dave about this, he said he'd been 'awake' – his actual word -for only fifty years altogether, in the thousand since his – er – metamorphosis.
   When I asked if he resented this takeover of his life, he said, 'Why should I resent it? I am performing my functions perfectly.' Yes, that sounds exactly like Hal! But I believe it was Dave – if there's any distinction now.
   Remember that Swiss Army knife analogy? Halman is one of this cosmic knife's myriad of components.
   But he's not a completely passive tool – when he's awake, he has some autonomy, some independence – presumably within limits set by the Monolith's overriding control. During the centuries, he's been used as a kind of intelligent probe to examine, Jupiter – as you've just seen – as well as Ganymede and the Earth. That confirms those mysterious events in Florida, reported by Dave's old girl-friend, and the nurse who was looking after his mother, just moments before her death... as well as the encounters in Anubis City.
   And it also explains another mystery. I asked Dave directly: why was I allowed to land on Europa, when everyone else has been turned away for centuries? I fully expected to be!
   The answer's ridiculously simple. The Monolith uses Dave – Halman – from time to time, to keep an eye on us.
   Dave knew all about my rescue – even saw some of the media interviews I made, on Earth and on Ganymede. I must say I'm still a little hurt he made no attempt to contact me! But at least he put out the Welcome mat when I did arrive...
   Dim – I still have forty-eight hours before Falcon leaves – with or without me! I don't think I'll need them, now I've made contact with Halman; we can keep in touch just as easily from Anubis... if he wants to do so.
   And I'm anxious to get back to the Grannymede as quickly as possible. Falcon's a fine little spacecraft, but her plumbing could be improved – it's beginning to smell in here, and I'm itching for a shower.
   Look forward to seeing you – and especially Ted Khan.
   We have much to talk about, before I return to Earth.
   TRANSMIT
   STORE

V – TERMINATION

   The toil of all that be
   Heals not the primal fault;
   It rains into the sea,
   And still the sea is salt.

– A. E. Housman, More Poems
32 – A Gentleman of Leisure

   On the whole, it had been an interesting but uneventful decades, punctuated by the joys and sorrows which Time and Fate bring to all mankind. The greatest of those had been wholly unexpected; in fact, before he left for Ganymede, Poole would have dismissed the very idea as preposterous.
   There is much truth in the saying that absence makes the heart grow fonder. When he and Indra Wallace met again, they discovered that, despite their bantering and occasional disagreements, they were closer than they had imagined. One thing led to another including, to their mutual joy, Dawn Wallace and Martin Poole.
   It was rather late in life to start a family – quite apart from that little matter of a thousand years – and Professor Anderson had warned them that it might be impossible. Or even worse...
   'You were lucky in more ways than you realize,' he told Poole. 'Radiation damage was surprisingly low, and we were able to make all essential repairs from your intact DNA. But until we do some more tests, I can't promise genetic integrity. So enjoy yourselves – but don't start a family until I give the OK.'
   The tests had been time-consuming, and as Anderson had feared, further repairs were necessary. There was one major set-back – something that could never have lived, even if it had been allowed to go beyond the first few weeks after conception – but Martin and Dawn were perfect, with just the right number of heads, arms and legs. They were also handsome and intelligent, and barely managed to escape being spoiled by their doting parents – who continued to be the best of friends when, after fifteen years, each opted for independence again. Because of their Social Achievement Rating, they would have been permitted – indeed, encouraged – to have another child, but they decided not to put any more of a burden on their astonishingly good luck.
   One tragedy had shadowed Poole's personal life during this period – and indeed had shocked the whole Solar community. Captain Chandler and his entire crew had been lost when the nucleus of a comet they were reconnoitring exploded suddenly, destroying Goliath so completely that only a few fragments were ever located. Such explosions – caused by reactions among unstable molecules which existed at very low temperatures – were a well-known danger to comet-collectors, and Chandler had encountered several during his career. No one would ever know the exact circumstances which caused so experienced a spaceman to be taken by surprise.
   Poole missed Chandler very badly: he had played a unique role in his life, and there was no one to replace him – no one, except Dave Bowman, with whom he had shared so momentous an adventure. He and Chandler had often made plans to go into space together again, perhaps all the way out to the Oort Cloud with its unknown mysteries and its remote but inexhaustible wealth of ice. Yet some conflict of schedules had always upset their plans, so this was a wished-for future that would never exist.
   Another long-desired goal Poole had managed to achieve – despite doctor's orders. He had been down to Earth: and once was quite enough.
   The vehicle in which he had travelled looked almost identical to the wheelchairs used by the luckier paraplegics of his own time. It was motorized, and had balloon tyres which allowed it to roll over reasonably smooth surfaces. However, it could also fly – at an altitude of about twenty centimetres – on an aircushion produced by a set of small but very powerful fans. Poole was surprised that so primitive a technology was still in use, but inertia-control devices were too bulky for such small-scale applications.
   Seated comfortably in his hoverchair, he was scarcely conscious of his increasing weight as he descended into the heart of Africa; though he did notice some difficulty in breathing, he had experienced far worse during his astronaut training. What he was not prepared for was the blast of furnace-heat that smote him as he rolled out of the gigantic, sky-piercing cylinder that formed the base of the Tower. Yet it was still morning: what would it be like at noon?
   He had barely accustomed himself to the heat when his sense of smell was assailed. A myriad odours – none unpleasant, but all unfamiliar – clamoured for his attention. He closed his eyes for a few minutes, in an attempt to avoid overloading his input circuits.
   Before he had decided to open them again, he felt some large, moist object palpating the back of his neck.
   'Say hello to Elizabeth,' said his guide, a burly young man dressed in traditional Great White Hunter garb, much too smart to have seen any real use: 'she's our official greeter.'
   Poole twisted round in his chair, and found himself looking into the soulful eyes of a baby elephant.
   'Hello, Elizabeth,' he answered, rather feebly. Elizabeth lifted her trunk in salute, and emitted a sound not usually heard in polite society, though Poole felt sure it was well-intentioned.
   Altogether, he spent less than an hour on Planet Earth, skirting the edge of a jungle whose stunted trees compared unfavourably with Skyland's, and encountering much of the local fauna. His guides apologized for the friendliness of the lions, who had been spoilt by tourists – but the malevolent expressions of the crocodiles more than compensated; here was Nature raw and unchanged.
   Before he returned to the Tower, Poole risked taking a few steps away from his hoverchair. He realized that this would be the equivalent of carrying his own weight on his back, but that did not seem an impossible feat, and he would never forgive himself unless he attempted it.
   It was not a good idea; perhaps he should have tried it in a cooler climate. After no more than a dozen steps, he was glad to sink back into the luxurious clutches of the chair.
   'That's enough,' he said wearily. 'Let's go back to the Tower.'
   As he rolled into the elevator lobby, he noticed a sign which he had somehow overlooked during the excitement of his arrival. It read:

   WELCOME TO AFRICA! 'In wildness is the preservation of the world.' HENRY DAVID THOREAU (1817-1862)

   Observing Poole's interest, the guide asked 'Did you know him?'
   It was the sort of question Poole heard all too often, and at the moment he did not feel equipped to deal with it.
   'I don't think so,' he answered wearily, as the great doors closed behind them, shutting out the sights, scents and sounds of Mankind's earliest home.
   His vertical safari had satisfied his need to visit Earth, and he did his best to ignore the various aches and pains acquired there when he returned to his apartment at Level 10,000 – a prestigious location, even in this democratic society. Indra, however, was mildly shocked by his appearance, and ordered him straight to bed.
   'Just like Antaeus – but in reverse!' she muttered darkly. 'Who?' asked Poole: there were times when his wife's erudition was a little overwhelming, but he had determined never to let it give him an inferiority complex.
   'Son of the Earth Goddess, Gaea. Hercules wrestled with him – but every time he was thrown to the ground, Antaeus renewed his strength.'
   'Who won?'
   'Hercules, of course – by holding Antaeus in the air, so Ma couldn't recharge his batteries.'
   'Well, I'm sure it won't take me long to recharge mine. And I've learned one lesson. If I don't get more exercise, I may have to move up to Lunar Gravity level.'
   Poole's good resolution lasted a full month: every morning he went for a brisk five-kilometre walk, choosing a different level of the Africa Tower each day. Some floors were still vast, echoing deserts of metal which would probably never be occupied, but others had been landscaped and developed over the centuries in a bewildering variety of architectural styles. Many were borrowings from past ages and cultures; others hinted at futures which Poole would not care to visit. At least there was no danger of boredom, and on many of his walks he was accompanied, at a respectful distance, by small groups of friendly children. They were seldom able to keep up with him for long.
   One day, as Poole was striding down a convincing – though sparsely populated – imitation of the Champs Elyse´es, he suddenly spotted a familiar face.
   'Danil!' he called.
   The other man took not the slightest notice, even when Poole called again, more loudly.
   'Don't you remember me?'
   Danil – and now that he had caught up with him, Poole did not have the slightest doubt of his identity – looked genuinely baffled.
   'I'm sorry,' he said. 'You're Commander Poole, of course. But I'm sure we've never met before.'
   Now it was Poole's turn to be embarrassed.
   'Stupid of me,' he apologized. 'Must have mistaken you for someone else. Have a good day.'
   He was glad of the encounter, and was pleased to know that Danil was back in normal society. Whether his original crime had been axe-murders or overdue library books should no longer be the concern of his one-time employer; the account had been settled, the books closed. Although Poole sometimes missed the cops-and-robbers dramas he had often enjoyed in his youth, he had grown to accept the current wisdom: excessive interest in pathological behaviour was itself pathological.
   With the help of Miss Pringle, Mk III, Poole had been able to schedule his life so that there were even occasional blank moments when he could relax and set his Braincap on Random Search, scanning his areas of interest. Outside his immediate family, his chief concerns were still among the moons of Jupiter/Lucifer, not least because he was recognized as the leading expert on the subject, and a permanent member of the Europa Committee.
   This had been set up almost a thousand years ago, to consider what, if anything, could and should be done about the mysterious satellite. Over the centuries, it had accumulated a vast amount of information, going all the way back to the Voyager flybys of 1979 and the first detailed surveys from the orbiting Galileo spacecraft of 1996.
   Like most long-lived organizations, the Europa Committee had become slowly fossilized, and now met only when there was some new development. It had woken up with a start after Halman's reappearance, and appointed an energetic new chairperson whose first act had been to co-opt Poole.
   Though there was little that he could contribute that was not already recorded, Poole was very happy to be on the Committee. It was obviously his duty to make himself available, and it also gave him an official position he would otherwise have lacked. Previously his status was what had once been called a 'national treasure', which he found faintly embarrassing. Although he was glad to be supported in luxury by a world wealthier than all the dreams of war-ravaged earlier ages could have imagined, he felt the need to justify his existence.
   He also felt another need, which he seldom articulated even to himself. Halman had spoken to him, if only briefly, at their strange encounter two decades ago. Poole was certain that, if he wished, Halman could easily do so again. Were all human contacts no longer of interest to him? He hoped that was not the case; yet that might be one explanation of his silence.
   He was frequently in touch with Theodore Khan – as active and acerbic as ever, and now the Europa Committee's representative on Ganymede. Ever since Poole had returned to Earth, Ted had been trying in vain to open a channel of communication with Bowman. He could not understand why long lists of important questions on subjects of vital philosophical and historic interest received not even brief acknowledgements.
   'Does the Monolith keep your friend Halman so busy that he can't talk to me?' he complained to Poole. 'What does he do with his time, anyway?'
   It was a very reasonable question; and the answer came, like a thunderbolt out of a cloudless sky, from Bowman himself – as a perfectly commonplace vidphone call.

33 – Contact

   'Hello, Frank. This is Dave. I have a very important message for you. I assume that you are now in your suite in Africa Tower. If you are there, please identify yourself by giving the name of our instructor in orbital mechanics. I will wait for sixty seconds, and if there is no reply will try again in exactly one hour.'
   That minute was hardly long enough for Poole to recover from the shock. He felt a brief surge of delight, as well as astonishment, before another emotion took over. Glad though he was to hear from Bowman again, that phrase 'a very important message' sounded distinctly ominous.
   At least it was fortunate, Poole told himself, that he's asked for one of the few names I can remember. Yet who could forget a Scot with a Glasgow accent so thick it had taken them a week to master it? But he had been a brilliant lecturer – once you understood what he was saying.
   'Dr Gregory McVitty.'
   'Accepted. Now please switch on your Braincap receiver. It will take three minutes to download this message. Do not attempt to monitor: I am using ten-to-one compression. I will wait two minutes before starting.'
   How is he managing to do this? Poole wondered. Jupiter/Lucifer was now over fifty light-minutes away, so this message must have left almost an hour ago. It must have been sent with an intelligent agent in a properly addressed package on the Ganymede-Earth beam – but that would have been a trivial feat to Halman, with the resources he had apparently been able to tap inside the Monolith.
   The indicator light on the Brainbox was flickering. The message was coming through.
   At the compression Halman was using, it would take half an hour for Poole to absorb the message in real-time. But he needed only ten minutes to know that his peaceful life-style had come to an abrupt end

34 – Judgement

   In a world of universal and instantaneous communication, it was very difficult to keep secrets. This was a matter, Poole decided immediately, for face-to-face discussion.
   The Europa Committee had grumbled, but all its members had assembled in his apartment. There were seven of them – the lucky number, doubtless suggested by the phases of the Moon, that had always fascinated Mankind. It was the first time Poole had met three of the Committee's members, though by now he knew them all more thoroughly than he could possibly have done in a pre-Braincapped lifetime.
   'Chairperson Oconnor, members of the Committee – I'd like to say a few words – only a few, I promise! – before you download the message I've received from Europa. And this is something I prefer to do verbally; that's more natural for me – I'm afraid I'll never be quite at ease with direct mental transfer.'
   'As you all know, Dave Bowman and Hal have been stored as emulations in the Monolith on Europa. Apparently it never discards a tool it once found useful, and from time to time it activates Halman, to monitor our affairs – when they begin to concern it. As I suspect my arrival may have done – though perhaps I flatter myself.'
   'But Halman isn't just a passive tool. The Dave component still retains something of its human origins – even emotions. And because we were trained together – shared almost everything for years – he apparently finds it much easier to communicate with me than with anyone else. I would like to think he enjoys doing it, but perhaps that's too strong a word.'
   'He's also curious – inquisitive – and perhaps a little resentful of the way he's been collected, like a specimen of wildlife. Though that's probably what we are, from the viewpoint of the intelligence that created the Monolith.'
   'And where is that intelligence now? Halman apparently knows the answer, and it's a chilling one.'
   'As we always suspected, the Monolith is part of a galactic network of some kind. And the nearest node – the Monolith's controller, or immediate superior – is 450 light-years away.'
   'Much too close for comfort! This means that the report on us and our affairs that was transmitted early in the twenty-first century was received half a millennium ago. If the Monolith's – let's say Supervisor – replied at once, any further instructions should be arriving just about now.'
   'And that's exactly what seems to be happening. During the last few days, the Monolith has been receiving a continuous string of messages, and has been setting up new programs, presumably in accordance with these.'
   'Unfortunately, Halman can only make guesses about the nature of those instructions. As you'll gather when you've downloaded this tablet, he has some limited access to many of the Monolith's circuits and memory banks, and can even carry on a kind of dialogue with it. If that's the right word – since you need two people for that! I still can't really grasp the idea that the Monolith, for all its powers, doesn't possess consciousness – doesn't even know that it exists!'
   'Halman's been brooding over the problem for a thousand years – on and off – and has come to the same answer that most of us have done. But his conclusion must surely carry far more weight, because of his inside knowledge.'
   'Sorry! I wasn't intending to make a joke – but what else could you call it?'
   'Whatever went to the trouble of creating us – or at least tinkering with our ancestors' minds and genes – is deciding what to do next. And Halman is pessimistic. No – that's an exaggeration. Let's say he doesn't think much of our chances, but is now too detached an observer to be unduly worried. The future – the survival! – of the human race isn't much more than an interesting problem to him, but he's willing to help.'
   Poole suddenly stopped talking, to the surprise of his intent audience.
   'That's strange. I've just had an amazing flashback... I'm sure it explains what's happening. Please bear with me.'
   'Dave and I were walking together one day, along the beach at the Cape, a few weeks before launch, when we noticed a large beetle lying on the sand. As often happens, it had fallen on its back and was waving its legs in the air, struggling to get right-way-up.'
   'I ignored it – we were engaged in some complicated technical discussion – but not Dave. He stepped aside, and carefully flipped it over with his shoe. As it flew away I commented, "Are you sure that was a good idea? Now it will go off and chomp somebody's prize chrysanthemums." And he answered, "Maybe you're right. But I'd like to give it the benefit of the doubt."
   'My apologies – I'd promised to say only a few words! But I'm very glad I remembered that incident: I really believe it puts Halman's message in the right perspective. He's giving the human race the benefit of the doubt...'
   'Now please check your Braincaps. This is a high-density recording – top of the u.v. band, Channel 110. Make yourselves comfortable, but be sure you're free line of sight. Here we go...'

35 – Council of War

   No one asked for a replay. Once was sufficient.
   There was a brief silence when the playback finished; then Chairperson Dr Oconnor removed her Braincap, massaged her shining scalp, and said slowly:
   'You taught me a phrase from your period that seems very appropriate now. This is a can of worms.'
   'But only Bowman – Halman – has opened it,' said one of the Committee members. 'Does he really understand the operation of something as complex as the Monolith? Or is this whole scenario a figment of his imagination?'
   'I don't think he has much imagination,' Dr Oconnor answered. 'And everything checks perfectly. Especially the reference to Nova Scorpio. We assumed that was an accident; apparently it was a – judgement.'
   'First Jupiter – now Scorpio,' said Dr Kraussman, the distinguished physicist who was popularly regarded as a reincarnation of the legendary Einstein. A little plastic surgery, it was rumoured, had also helped. 'Who will be next in line?'
   'We always guessed,' said the Chair, 'that the TMAs were monitoring us.' She paused for a moment, then added ruefully: 'What bad – what incredibly bad! – luck that the fmal report went off, just after the very worst period in human history!'
   There was another silence. Everyone knew that the twentieth century had often been branded 'The Century of Torture'
   Poole listened without interrupting, while he waited for some consensus to emerge. Not for the first time, he was impressed by the quality of the Committee No one was trying to prove a pet theory, score debating points, or inflate an ego: he could not help drawing a contrast with the often bad-tempered arguments he had heard in own time, between Space Agency engineers and administrators, Congressional staffs, and industrial executives.
   Yes, the human race had undoubtedly improved. The Braincap had not only helped to weed out misfits, but had enormously increased the efficiency of education. Yet there had also been a loss; there were very few memorable characters in this society. Offhand he could think of only four – Indra, Captain Chandler, Dr Khan and the Dragon Lady of wistful memory.
   The Chairperson let the discussion flow smoothly back and forth until everyone had had a say, then began her summing up.
   'The obvious first question – how seriously should we take this threat – isn't worth wasting time on. Even if it's a false alarm, or a misunderstanding, it's potentially so grave that we must assume it's real, until we have absolute proof to the contrary. Agreed?'
   'Good. And we don't know how much time we have. So we must assume that the danger is immediate. Perhaps Halman may be able to give us some further warning, but by then it may be too late.'
   'So the only thing we have to decide is: how can we protect ourselves, against something as powerful as the Monolith? Look what happened to Jupiter! And, apparently, Nova Scorpio...'
   'I'm sure that brute force would be useless, though perhaps we should explore that option. Dr Kraussman – how long would it take to build a super-bomb?'
   'Assuming that the designs still exist, so that no research is necessary – oh, perhaps two weeks. Thermonuclear weapons are rather simple, and use common materials – after all, they made them back in the Second Millennium! But if you wanted something sophisticated – say an antimatter bomb, or a mini-black-hole – well, that might take a few months.'
   'Thank you: could you start looking into it? But as I've said, I don't believe it would work; surely something that can handle such powers must also be able to protect itself against them. So – any other suggestions?'
   'Can we negotiate?' one councillor asked, not very hopefully.
   'With what... or whom?' Kraussman answered. 'As we've discovered, the Monolith is essentially a pure mechanism, doing just what it's been programmed to do. Perhaps that program is flexible enough to allow of changes, but there's no way we can tell. And we certainly can't appeal to Head Office – that's half a thousand light-years away!'
   Poole listened without interrupting; there was nothing he could contribute to the discussion, and indeed much of it was completely over his head. He began to feel an insidious sense of depression, would it have been better, he wondered, not to pass on this information? Then, if it was a false alarm, no one would be any the worse. And if it was not – well, humanity would still have peace of mind, before whatever inescapable doom awaited it.
   He was still mulling over these gloomy thoughts when he was suddenly alerted by a familiar phrase.
   A quiet little member of the Committee, with a name so long and difficult that Poole had never been able to remember, still less pronounce it, had abruptly dropped just two words into the discussion.
   'Trojan Horse!'
   There was one of those silences generally described as 'pregnant', then a chorus of 'Why didn't I think of that!' 'Of course!' 'Very good idea!' until the Chairperson, for the first time in the session, had to call for order.
   'Thank you, Professor Thirugnanasampanthamoorthy,' said Dr Oconnor, without missing a beat. 'Would you like to be more specific?'
   'Certainly. If the Monolith is indeed, as everyone seems to think, essentially a machine without consciousness – and hence with only limited self-monitoring ability – we may already have the weapons that can defeat it. Locked up in the Vault.'
   'And a delivery system – Halman!'
   'Precisely.'
   'Just a minute, Dr T. We know nothing – absolutely nothing – about the Monolith's architecture. How can we be sure that anything our primitive species ever designed would be effective against it?'
   'We can't – but remember this. However sophisticated it is, the Monolith has to obey exactly the same universal laws of logic that Aristotle and Boole formulated, centuries ago. That's why it may – no, should! – be vulnerable to the things locked up in the Vault. We have to assemble them in such a way that at least one of them will work. It's our only hope – unless anybody can suggest a better alternative.'
   'Excuse me,' said Poole, finally losing patience. 'Will someone kindly tell me – what and where is this famous Vault you're talking about?'

36 – Chamber of Horrors

   History is full of nightmares, some natural, some manmade.
   By the end of the twenty-first century, most of the natural ones – smallpox, the Black Death, AIDS, the hideous viruses lurking in the African jungle – had been eliminated, or at least brought under control, by the advance of medicine. However, it was never wise to underestimate the ingenuity of Mother Nature, and no one doubted that the future would still have unpleasant biological surprises in store for Mankind.
   It seemed a sensible precaution, therefore, to keep a few specimens of all these horrors for scientific study – carefully guarded, of course, so that there was no possibility of them escaping and again wreaking havoc on the human race. But how could one be absolutely sure that there was no danger of this happening?
   There had been – understandably – quite an outcry in the late twentieth century when it was proposed to keep the last known smallpox viruses at Disease Control Centres in the United States and Russia. However unlikely it might be, there was a finite possibility that they might be released by such accidents as earthquakes, equipment failures – or even deliberate sabotage by terrorist groups.
   A solution that satisfied everyone (except a few 'Preserve the lunar wilderness!' extremists) was to ship them to the Moon, and to keep them in a laboratory at the end of a kilometre-long shaft drilled into the isolated mountain Pico, one of the most prominent features of the Mare Imbrium. And here, over the years, they were joined by some of the most outstanding examples of misplaced human ingenuity – indeed, insanity.
   There were gases and mists that, even in microscopic doses, caused slow or instant death. Some had been created by religious cultists who, though mentally deranged, had managed to acquire considerable scientific knowledge. Many of them believed that the end of the world was at hand (when, of course, only their followers would be saved). In case God was absent-minded enough not to perform as scheduled, they wanted to make sure that they could rectify His unfortunate oversight.
   The first assaults of these lethal cultists were made on such vulnerable targets as crowded subways, World Fairs, sports stadiums, pop concerts... tens of thousands were killed, and many more injured before the madness was brought under control in the early twenty-first century. As often happens, some good came out of evil, because it forced the world's law-enforcement agencies to co-operate as never before; even rogue states which had promoted political terrorism were unable to tolerate this random and wholly unpredictable variety.
   The chemical and biological agents used in these attacks – as well as in earlier forms of warfare – joined the deadly collection in Pico. Their antidotes, when they existed, were also stored with them. It was hoped that none of this material would ever concern humanity again – but it was still available, under heavy guard, if it was needed in some desperate emergency.
   The third category of items stored in the Pico vault, although they could be classified as plagues, had never killed or injured anyone – directly. They had not even existed before the late twentieth century, but in a few decades they had done billions of dollars' worth of damage, and often wrecked lives as effectively as any bodily illness could have done. They were the diseases which attacked Mankind's newest and most versatile servant, the computer.
   Taking names from the medical dictionaries – viruses, prions, tapeworms – they were programs that often mimicked, with uncanny accuracy, the behaviour of their organic relatives. Some were harmless – little more than playful jokes, contrived to surprise or amuse Computer operators by unexpected messages and images on their visual displays. Others were far more malicious – deliberately designed agents of catastrophe.
   In most cases their purpose was entirely mercenary; they were the weapons that sophisticated criminals used to blackmail the banks and commercial organizations that now depended utterly upon the efficient operation of their computer systems. On being warned that their data banks would be erased automatically at a certain time, unless they transferred a few megadollars to some anonymous offshore number, most victims decided not to risk possibly irreparable disaster. They paid up quietly, often – to avoid public or even private embarrassment – without notifying the police.
   This understandable desire for privacy made it easy for the network highwaymen to conduct their electronic holdups: even when they were caught, they were treated gently by legal systems which did not know how to handle such novel crimes – and, after all, they had not really hurt anyone, had they? Indeed, after they had served their brief sentences, many of the perpetrators were quietly hired by their victims, on the old principle that poachers make the best game-keepers.
   These computer criminals were driven purely by greed, and certainly did not wish to destroy the organizations they preyed upon: no sensible parasite kills its host. But there were other, and much more dangerous, enemies of society at work...
   Usually, they were maladjusted individuals – typically adolescent males – working entirely alone, and of course in complete secrecy. Their aim was to create programs which would simply create havoc and confusion, when they had been spread over the planet by the world-wide cable and radio networks, or on physical carriers such as diskettes and CD ROMS. Then they would enjoy the resulting chaos, basking in the sense of power it gave their pitiful psyches.
   Sometimes, these perverted geniuses were discovered and adopted by national intelligence agencies for their own secretive purposes – usually, to break into the data banks of their rivals. This was a fairly harmless line of employment, as the organizations concerned did at least have some sense of civic responsibility.
   Not so the apocalyptic sects, who were delighted to discover this new armoury, holding weapons far more effective, and more easily disseminated, than gas or germs. And much more difficult to counter, since they could be broadcast instantaneously to millions of offices and homes.
   The collapse of the New York-Havana Bank in 2005, the launching of Indian nuclear missiles in 2007 (luckily with their warheads unactivated), the shutdown of Pan-European Air Traffic Control in 2008, the paralysis of the North American telephone network in that same year – all these were cult-inspired rehearsals for Doomsday. Thanks to brilliant feats of counterintelligence by normally uncooperative, and even warring, national agencies, this menace was slowly brought under control.
   At least, so it was generally believed: there had been no serious attacks at the very foundations of society for several hundred years. One of the chief weapons of victory had been the Braincap – though there were some who believed that this achievement had been bought at too great a cost.
   Though arguments over the freedom of the Individual versus the duties of the State were old when Plato and Aristotle attempted to codify them, and would probably continue until the end of time, some consensus had been reached in the Third Millennium. It was generally agreed that Communism was the most perfect form of government; unfortunately it had been demonstrated – at the cost of some hundreds of millions of lives – that it was only applicable to social insects, Robots Class II, and similar restricted categories. For imperfect human beings, the least-worst answer was Demosocracy, frequently defined as 'individual greed, moderated by an efficient but not too zealous government'.
   Soon after the Braincap came into general use, some highly intelligent – and maximally zealous – bureaucrats realized that it had a unique potential as an early-warning system. During the setting-up process, when the new wearer was being mentally 'calibrated' it was possible to detect many forms of psychosis before they had a chance of becoming dangerous. Often this suggested the best therapy, but when no cure appeared possible the subject could be electronically tagged – or, in extreme cases, segregated from society. Of course, this mental monitoring could test only those who were fitted with a Braincap – but by the end of the Third Millennium this was as essential for everyday life as the personal telephone had been at its beginning. In fact, anyone who did not join the vast majority was automatically suspect, and checked as a potential deviant.
   Needless to say, when 'mind-probing', as its critics called it, started coming into general use, there were cries of outrage from civil-rights organizations; one of their most effective slogans was 'Braincap or Braincop?' Slowly – even reluctantly – it was accepted that this form of monitoring was a necessary precaution against far worse evils; and it was no coincidence that with the general improvement in mental health, religious fanaticism also started its rapid decline-
   When the long-drawn-out war against the cybernet criminals ended, the victors found themselves owning an embarrassing collection of spoils, all of them utterly incomprehensible to any past conqueror. There were, of course, hundreds of computer viruses, most of them very difficult to detect and kill. And there were some entities – for want of a better name – that were much more terrifying. They were brilliantly invented diseases for which there was no cure – in some cases not even the possibility of a cure
   Many of them had been linked to great mathematicians who would have been horrified by this corruption of their discoveries. As it is a human characteristic to belittle a real danger by giving it an absurd name, the designations were often facetious: the Godel Gremlin, the Mandelbrot Maze, the Combinatorial Catastrophe, the Transfinite Trap, the Conway Conundrum, the Turing Torpedo, the Lorentz Labyrinth, the Boolean Bomb, the Shannon Snare, the Cantor Cataclysm...
   If any generalization was possible, all these mathematical horrors operated on the same principle. They did not depend for their effectiveness on anything as naïve as memory-erasure or code corruption – on the contrary. Their approach was more subtle; they persuaded their host machine to initiate a program which could not be completed before the end of the universe, or which – the Mandelbrot Maze was the deadliest example – involved a literally infinite series of steps.
   A trivial example would be the calculation of Pi, or any other irrational number. However, even the most stupid electro-optic computer would not fall into such a simple trap: the day had long since passed when mechanical morons would wear out their gears, grinding them to powder as they tried to divide by zero...
   The challenge to the demon programmers was to convince their targets that the task set them had a definite conclusion that could be reached in a finite time. In the battle of wits between man (seldom woman, despite such role-models as Lady Ada Lovelace, Admiral Grace Hopper and Dr Susan Calvin) and machine, the machine almost invariably lost.
   It would have been possible – though in some cases difficult and even risky – to destroy the captured obscenities by ERASE/OVERWRITE commands, but they represented an enormous investment in time and ingenuity which, however misguided, seemed a pity to waste. And, more important, perhaps they should be kept for study, in some secure location, as a safeguard against the time when some evil genius might reinvent and deploy them.
   The solution was obvious. The digital demons should be sealed with their chemical and biological counterparts, it was hoped for ever, in the Pico Vault.

37 – Operation Damocles

   Poole never had much contact with the team who assembled the weapon everyone hoped would never have to be used. The operation – ominously, but aptly, named Damocles – was so highly specialized that he could contribute nothing directly, and he saw enough of the task force to realize that some of them might almost belong to an alien species. Indeed, one key member was apparently in a lunatic asylum – Poole had been surprised to find that such places still existed – and Chairperson Oconnor sometimes suggested that at least two others should join him.
   'Have you ever heard of the Enigma Project?' she remarked to Poole, after a particularly frustrating session. When he shook his head, she continued: 'I'm surprised – it was only a few decades before you were born: I came across it while when I was researching material for Damocles. Very similar problem – in one of your wars, a group of brilliant mathematicians was gathered together, in great secrecy, to break an enemy code... incidentally, they built one of the very first real computers, to make the job possible.'
   'And there's a lovely story – I hope it's true – that reminds me of our own little team. One day the Prime Minister came on a visit of inspection, and afterwards he said to Enigma's Director: "When I told you to leave no stone unturned to get the men you needed, I didn't expect you to take me so literally".'
   Presumably all the right stones had been turned for Project Damocles. However, as no one knew whether they were working against a deadline of days, weeks or years, at first it was hard to generate any sense of urgency. The need for secrecy also created problems; since there was no point in spreading alarm throughout the Solar System, not more than fifty people knew of the project. But they were the people who mattered – who could marshal all the forces necessary, and who alone could authorize the opening of the Pico Vault, for the first time in five hundred years.
   When Halman reported that the Monolith was receiving messages with increasing frequency, there seemed little doubt that something was going to happen. Poole was not the only one who found it hard to sleep in those days, even with the help of the Braincap's anti-insomnia programs. Before he finally did get to sleep, he often wondered if he would wake up again. But at last all the components of the weapon were assembled – a weapon invisible, untouchable and unimaginable to almost all the warriors who had ever lived.
   Nothing could have looked more harmless and innocent than the perfectly standard terabyte memory tablet, used with millions of Braincaps every day. But the fact that it was encased in a massive block of crystalline material, criss-crossed with metal bands, indicated that it was something quite out of the ordinary. Poole received it with reluctance; he wondered if the courier who had been given the awesome task of carrying the Hiroshima atom bomb's core to the Pacific airbase from which it was launched had felt the same way. And yet, if all their fears were justified, his responsibility might be even greater.
   And he could not be certain that even the first part of his mission would be successful. Because no circuit could be absolutely secure, Halman had not yet been informed about Project Damocles; Poole would do that when he returned to Ganymede.
   Then he could only hope that Halman would be willing to play the role of Trojan Horse – and, perhaps, be destroyed in the process.

38 – Pre-emptive Strike

   It was strange to be back in the Hotel Grannymede after all these years – strangest of all, because it seemed completely unchanged, despite everything that had happened. Poole was still greeted by the familiar image of Bowman as he walked into the suite named after him: and, as he expected, Bowman/Halman was waiting, looking slightly less substantial than the ancient hologram.
   Before they could even exchange greetings, there was an interruption that Poole would have welcomed – at any other time than this. The room vidphone gave its urgent trio of rising notes – also unchanged since his last visit -and an old friend appeared on the screen.
   'Frank!' cried Theodore Khan, 'why didn't you tell me you were coming! When can we meet? Why no video – someone with you? And who were all those official-looking types who landed at the same time -'
   'Please Ted! Yes, I'm sorry – but believe me, I've got very good reasons – I'll explain later. And I do have someone with me – call you back just as soon as I can. Good-bye!'
   As he belatedly gave the 'Do Not Disturb' order, Poole said apologetically: 'Sorry about that – you know who it was, of course.'
   'Yes – Dr Khan. He often tried to get in touch with me.'
   'But you never answered. May I ask why?' Though there were far more important matters to worry about, Poole could not resist putting the question.
   'Ours was the only channel I wished to keep open. Also, I was often away. Sometimes for years.'
   That was surprising – yet it should not have been. Poole knew well enough that Halman had been reported in many places, in many times. Yet – 'away for years'? He might have visited quite a few star systems – perhaps that was how he knew about Nova Scorpio, only forty light-years distant. But he could never have gone all the way to the Node; there and back would have been a nine-hundred-year journey.
   'How lucky that you were here when we needed you!' It was very unusual for Halman to hesitate before replying. There was much longer than the unavoidable three-second time-lag before he said slowly 'Are you sure that it was luck?'
   'What do you mean?'
   'I do not wish to talk about it, but twice I have – glimpsed – powers – entities – far superior to the Monoliths, and perhaps even their makers. We may both have less freedom than we imagine.'
   That was indeed a chilling thought; Poole needed a deliberate effort of will to put it aside and concentrate on the immediate problem.
   'Let us hope we have enough free-will to do what is necessary. Perhaps this is a foolish question. Does the Monolith know that we are meeting? Could it be – suspicious?'
   'It is not capable of such an emotion. It has numerous fault-protection devices, some of which I understand. But that is all.'
   'Could it be overhearing us now?'
   'I do not believe so.'
   I wish that I could be sure it was such a naïve and simple-minded super-genius, thought Poole as he unlocked his briefcase and took out the sealed box containing the tablet. In this low gravity its weight was almost negligible; it was impossible to believe that it might hold the destiny of Mankind.
   'There was no way we could be certain of getting a secure circuit to you, so we couldn't go into details. This tablet contains programs which we hope will prevent the Monolith from carrying out any orders which threaten Mankind. There are twenty of the most devastating viruses ever designed on this, most of which have no known antidote; in some cases, it is believed that none is possible. There are five copies of each. We would like you to release them when – and if – you think it is necessary. Dave – Hal – no one has ever been given such a responsibility. But we have no other choice.'
   Once again, the reply seemed to take longer than the three-second round trip from Europa.
   'If we do this, all the Monolith's functions may cease. We are uncertain what will happen to us then.'
   'We have considered that, of course. But by this lime, you must surely have many facilities at your command -some of them probably beyond our understanding. I am also sending you a petabyte memory tablet. Ten to the fifteenth bytes is more than sufficient to hold all the memories and experiences of many lifetimes. This will give you one escape route: I suspect you have others.'
   'Correct. We will decide which to use at the appropriate time.'
   Poole relaxed – as far as was possible in this extraordinary situation. Halman was willing to co-operate: he still had sufficient links with his origins.
   'Now, we have to get this tablet to you – physically. Its contents are too dangerous to risk sending over any radio or optical channel. I know you possess long-range control of matter: did you not once detonate an orbiting bomb? Could you transport it to Europa? Alternatively, we could send it in an auto-courier, to any point you specify.'
   'That would be best: I will collect it in Tsienville. Here are the co-ordinates...

   Poole was still slumped in his chair when the Bowman Suite monitor admitted the head of the delegation that had accompanied him from Earth. Whether Colonel Jones was a genuine Colonel – or even if his name was Jones – were minor mysteries which Poole was not really interested in solving; it was sufficient that he was a superb organizer and had handled the mechanics of Operation Damocles with quiet efficiency.
   'Well, Frank – it's on its way. Will be landing in one hour, ten minutes. I assume that Halman can take it from there, but I don't understand how he can actually handle – is that the right word? – these tablets.'
   'I wondered about that, until someone on the Europa Committee explained it. There's a well-known – though not to me! – theorem stating that any computer can emulate any other computer. So I'm sure that Halman knows exactly what he's doing. He would never have agreed otherwise.'
   'I hope you're right,' replied the Colonel. 'If not – well, I don't know what alternative we have.'
   There was a gloomy pause, until Poole did his best to relieve the tension.
   'By the way, have you heard the local rumour about our visit?'
   'Which particular one?'
   'That we're a special commission sent here to investigate crime and corruption in this raw frontier township. The Mayor and the Sheriff are supposed to be running scared.'
   'How I envy them,' said 'Colonel Jones'. 'Sometimes it's quite a relief to have something trivial to worry about.'

39 – Deicide

   Like all the inhabitants of Anubis City (population now 56,521), Dr Theodore Khan woke soon after local midnight to the sound of the General Alarm. His first reaction was 'Not another Icequake, for Deus's sake!'
   He rushed to the window, shouting 'Open' so loudly that the room did not understand, and he had to repeat the order in a normal voice. The light of Lucifer should have come streaming in, painting the patterns on the floor that so fascinated visitors from Earth, because they never moved even a fraction of a millimetre, no matter how long they waited...
   That unvarying beam of light was no longer there. As Khan stared in utter disbelief through the huge, transparent bubble of the Anubis Dome, he saw a sky that Ganymede had not known for a thousand years. It was once more ablaze with stars; Lucifer had gone.
   And then, as he explored the forgotten constellations, Kahn noticed something even more terrifying. Where Lucifer should have been was a tiny disc of absolute blackness, eclipsing the unfamiliar stars.
   There was only one possible explanation, Khan told himself numbly. Lucifer has been swallowed by a Black Hole. And it may be our turn next.
   On the balcony of the Grannymede Hotel, Poole was watching the same spectacle, but with more complex emotions. Even before the general alarm, his comsec had woken him with a message from Halman.
   'It is beginning. We have infected the Monolith. But one – perhaps several – of the viruses have entered our own circuits. We do not know if we will be able to use the memory tablet you have given us. If we succeed, we will meet you in Tsienville.'
   Then came the surprising and strangely moving words whose exact emotional content would be debated for generations:
   'If we are unable to download, remember us.' From the room behind him, Poole heard the voice of the Mayor, doing his best to reassure the now sleepless citizens of Anubis. Though he opened with that most terrifying of official statements – 'No cause for alarm' – the Mayor did indeed have words of comfort.
   'We don't know what's happening but Lucifer's still shining normally! I repeat – Lucifer is still shining! We've just received news from the interorbit shuttle Alcyone, which left for Callisto half an hour ago. Here's their view -, Poole left the balcony and rushed into his room just in time to see Lucifer blaze reassuringly on the vidscreen.
   'What's happened,' the Mayor continued breathlessly, 'is that something has caused a temporary eclipse – we'll zoom in to look at it... Callisto Observatory, come in please...'
   How does he know it's 'temporary'? thought Poole, as he waited for the next image to come up on the screen.
   Lucifer vanished, to be replaced by a field of stars. At the same time, the Mayor faded out and another voice took over:
   '– two-metre telescope, but almost any instrument will do. It's a disc of perfectly black material, just over ten thousand kilometres across, so thin it shows no visible thickness. And it's placed exactly – obviously deliberately -to block Ganymede from receiving any light.
   'We'll zoom in to see if it shows any details, though I rather doubt it...'
   From the viewpoint of Callisto, the occulting disc was foreshortened into an oval, twice as long as it was wide. It expanded until it completely filled the screen; thereafter, it was impossible to tell whether the image was being zoomed, as it showed no structure whatsoever.
   'As I thought – there's nothing to see. Let's pan over to the edge of the thing...'
   Again there was no sense of motion, until a field of stars suddenly appeared, sharply defined by the curving edge of the world-sized disc. It was exactly as if they were looking past the horizon of an airless, perfectly smooth planet.
   No, it was not perfectly smooth...
   'That's interesting,' commented the astronomer, who until now had sounded remarkably matter-of-fact, as if this sort of thing was an everyday occurrence. 'The edge looks jagged – but in a very regular fashion – like a saw-blade...'
   A circular saw Poole muttered under his breath. Is it going to carve us up? Don't be ridiculous...
   'This is as close as we can get before diffraction spoils the image – we'll process it later and get much better detail:'
   The magnification was now so great that all trace of the disc's circularity had vanished. Across the vidscreen was a black band, serrated along its edge with triangles so identical that Poole found it hard to avoid the ominous analogy of a saw-blade. Yet something else was nagging at the back of his mind...
   Like everyone else on Ganymede, he watched the infinitely more distant stars drifting in and out of those geometrically perfect valleys. Very probably, many others jumped to the same conclusion even before he did.
   If you attempt to make a disc out of rectangular blocks -whether their proportions are 1:4:9 or any other – it cannot possibly have a smooth edge. Of course, you can make it as near a perfect circle as you like, by using smaller and smaller blocks. Yet why go to that trouble, if you merely wanted to build a screen large enough to eclipse a sun?
   The Mayor was right; the eclipse was indeed temporary. But its ending was the precise opposite of a solar one.
   First light broke through at the exact centre, not in the usual necklace of Bailey's Beads along the very edge. Jagged lines radiated from a dazzling pinhole – and now, under the highest magnification, the structure of the disc was being revealed. It was composed of millions of identical rectangles, perhaps the same size as the Great Wall of Europa. And now they were splitting apart: it was as if a gigantic jigsaw puzzle was being dismantled.
   Its perpetual, but now briefly interrupted, daylight was slowly returning to Ganymede, as the disc fragmented and the rays of Lucifer poured through the widening gaps. Now the components themselves were evaporating, almost as if they needed the reinforcement of each other's contact to maintain reality.
   Although it seemed like hours to the anxious watchers in Anubis City, the whole event lasted for less than fifteen minutes. Not until it was all over did anyone pay attention to Europa itself.
   The Great Wall was gone: and it was almost an hour before the news came from Earth, Mars and Moon that the Sun itself had appeared to flicker for a few seconds, before resuming business as usual.
   It had been a highly selective set of eclipses, obviously targeted at humankind. Nowhere else in the Solar System would anything have been noticed.
   In the general excitement, it was a little longer before the world realized that TMA ZERO and TMA ONE had both vanished, leaving only their four-million-year-old imprints on Tycho and Africa.

   It was the first time the Europs could ever have met humans, but they seemed neither alarmed nor surprised by the huge creatures moving among them at such lightning speed. Of course, it was not too easy to interpret the emotional state of something that looked like a small, leafless bush, with no obvious sense organs or means of communication. But if they were frightened by the arrival of Alcyone, and the emergence of its passengers, they would surely have remained hiding in their igloos.
   As Frank Poole, slightly encumbered by his protective suit and the gift of shining copper wire he was carrying, walked into the untidy suburbs of Tsienville, he wondered what the Europs thought of recent events. For them, there had been no eclipse of Lucifer, but the disappearance of the Great Wall must surely have been a shock. It had stood there for a thousand years, as a shield and doubtless much more; then, abruptly, it was gone, as if it had never been...
   The petabyte tablet was waiting for him, with a group of Europs standing around it, demonstrating the first sign of curiosity that Poole had ever observed in them. He wondered if Halman had somehow told them to watch over this gift from space, until he came to collect it.
   And to take it back, since it now contained not only a sleeping friend but terrors which some future age might exorcise, to the only place where it could be safely stored.

40 – Midnight: Pico

   It would be hard, Poole thought, to imagine a more peaceful scene – especially after the trauma of the last weeks. The slanting rays of a nearly full Earth revealed all the subtle details of the waterless Sea of Rains – not obliterating them, as the incandescent fury of the Sun would do.
   The small convoy of mooncars was arranged in a semicircle a hundred metres from the inconspicuous opening at the base of Pico that was the entrance to the Vault. From this viewpoint, Poole could see that the mountain did not live up to the name that the early astronomers, misled by its pointed shadow, had given to it. It was more like a rounded hill than a sharp peak, and he could well believe that one of the local pastimes was bicycle-riding to the summit. Until now, none of those sportsmen and women could have guessed at the secret hidden beneath their wheels: he hoped that the sinister knowledge would not discourage their healthy exercise.
   An hour ago, with a sense of mingled sadness and triumph, he had handed over the tablet he had brought -never letting it out of his sight – from Ganymede directly to the Moon.
   'Good-bye, old friends,' he had murmured. 'You've done well. Perhaps some future generation will reawaken you. But on the whole – I rather hope not.'
   He could imagine, all too clearly, one desperate reason why Halman's knowledge might be needed again. By now, surely, some message was on its way to that unknown control centre, bearing the news that its servant on Europa no longer existed. With reasonable luck, it would take 950 years, give or take a few, before any response could be expected.
   Poole had often cursed Einstein in the past; now he blessed him. Even the powers behind the Monoliths, it now appeared certain, could not spread their influence faster than the speed of light. So the human race should have almost a millennium to prepare for the next encounter – if there was to be one. Perhaps by that time, it would be better prepared.
   Something was emerging from the tunnel – the track-mounted, semi-humanoid robot that had carried the tablet into the Vault. It was almost comic to see a machine enclosed in the kind of isolation suit used as protection against deadly germs and here on the airless Moon! But no one was taking any chances, however unlikely they might seem. After all, the robot had moved among those carefully sequestered nightmares, and although according to its video cameras everything appeared in order, there was always a chance that some vial had leaked, or some canister's seal had broken. The Moon was a very stable environment, but during the centuries it had known many quakes and meteor impacts.
   The robot came to a halt fifty metres outside the tunnel. Slowly, the massive plug that sealed the Vault swung back into place, and began to rotate in its threads, like a giant bolt being screwed into the mountain.
   'All not wearing dark glasses, please close your eyes or look away from the robot!' said an urgent voice over the mooncar radio. Poole twisted round in his seat, just in time to see an explosion of light on the roof of the vehicle. When he turned back to look at Pico, all that was left of the robot was a heap of glowing slag; even to someone who had spent much of his life surrounded by vacuum, it seemed altogether wrong that tendrils of smoke were not slowly spiralling up from it.
   'Sterilization completed,' said the voice of the Mission Controller. 'Thank you, everybody. Now returning to Plato City.'
   How ironic – that the human race had been saved by the skilful deployment of its own insanities! What moral, Poole wondered, could one possibly draw from that?
   He looked back at the beautiful blue Earth, huddling beneath its tattered blanket of clouds for protection against the cold of space. Up there, a few weeks from now, he hoped to cradle his first grandson in his arms.
   Whatever godlike powers and principalities lurked beyond the stars, Poole reminded himself, for ordinary humans only two things were important – Love and Death.
   His body had not yet aged a hundred years: he still had plenty of time for both.