15 – Escape from the Giant

   When Floyd reached the observation deck – a discreet few minutes after Zenia – Jupiter already seemed farther away. But that must be an illusion based on his knowledge, not the evidence of his eyes. They had barely emerged from the Jovian atmosphere, and the planet still filled half the sky.
   And now they were – as intended – its prisoners. During the last incandescent hour, they had deliberately jettisoned the excess speed that could have carried them right out of the Solar System, and on to the stars. Now they were travelling in an ellipse – a classical Hohmann orbit – which would shuttle them back between Jupiter and the orbit of Io, 350,000 kilometres higher. If they did not – or could not – fire their motors again, Leonov would swing back and forth between these limits, completing one revolution every nineteen hours. It would become the closest of Jupiter's moons – though not for long. Each time it grazed the atmosphere it would lose altitude, until it spiralled into destruction.
   Floyd had never really enjoyed vodka, but he joined the others without any reservations in drinking a triumphant toast to the ship's designers, coupled with a vote of thanks to Sir Isaac Newton. Then Tanya put the bottle firmly back in its cupboard; there was still much to be done.
   Though they were all expecting it, everyone jumped at the sudden muffled thud of explosive charges, and the jolt of separation. A few seconds later, a large, still-glowing disk floated into view, slowly turning end-over-end as it drifted away from the ship.
   'Look!' cried Max. 'A flying saucer! Who's got a camera?' There was a distinct note of hysterical relief in the laughter that followed. It was interrupted by the captain, in a more serious vein.
   'Goodbye, faithful heat shield! You did a wonderful job.'
   'But what a waste!' said Sasha. 'There's at least a couple of tons left, Think of all the extra payload we could have carried!'
   'If that's good, conservative Russian engineering,' retorted Floyd, 'then I'm all for it. Far better a few tons too much – than one milligram too little.'
   Everyone applauded those noble sentiments as the jetti soned shield cooled to yellow, then red, and finally became as black as the space around it. It vanished from sight while only a few kilometres away, though occasionally the sudden reappearance of an eclipsed star would betray its presence.
   'Preliminary orbit check completed,' said Vasili. 'We're within ten metres a second of our right vector. Not bad for a first try.'
   There was a subdued sigh of relief at the news, and a few minutes later Vasili made another announcement.
   'Changing attitude for course correction; delta vee six metres a second. Twenty-second burn coming up in one minute.'
   They were still so close to Jupiter it was impossible to believe that the ship was orbiting the planet; they might have been in a high-flying aircraft that had just emerged from a sea of clouds. There was no sense of scale; it was easy to imagine that they were speeding away from some terrestrial sunset; the reds and pinks and crimsons sliding below were so familiar.
   And that was an illusion; nothing here had any parallels with Earth. Those colours were intrinsic, not borrowed from the setting sun. The very gases were utterly alien – methane and ammonia and a witch's brew of hydrocarbons, stirred in a hydrogen-helium cauldron. Not one trace of free oxygen, the breath of human life.
   The clouds marched from horizon to horizon in parallel rows, distorted by occasional swirls and eddies. Here and there upwellings of brighter gas broke the pattern, and Floyd could also see the dark rim of a great whirlpool, a maelstrom of gas leading down into unfathomable Jovian depths.
   He began to look for the Great Red Spot, then quickly checked himself at such a foolish thought. All the enormous cloudscape he could see below would be only a few per cent of the Red Spot's immensity; one might as well expect to recognize the shape of the United States from a small aeroplane flying low above Kansas.
   'Correction completed. We're now on interception orbit with Io. Arrival time: eight hours, fifty-five minutes.'
   Less than nine hours to climb up from Jupiter and meet whatever is waiting for us, thought Floyd. We've escaped from the giant – but he represents a danger we understood, and could prepare for. What lies ahead now is utter mystery.
   And when we have survived that challenge, we must return to Jupiter once again. We shall need his strength to send us safely home.

16 – Private Line

   '... Hello, Dimitri. This is Woody, switching to Key Two in fifteen seconds... Hello, Dimitri – multiply Keys Three and Four, take cube root, add pi squared and use nearest integer as Key Five. Unless your computers are a million times faster than ours – and I'm damn sure they're not – no one can decrypt this, on your side or mine. But you may have some explaining to do; anyway, you're good at that.
   'By the way, my usual excellent sources told me about the failure of the latest attempt to persuade old Andrei to resign; I gather that your delegation had no more luck than the others, and you're still saddled with him as President. I'm laughing my head off; it serves the Academy right. I know he's over ninety, and growing a bit – well, stubborn. But you won't get any help from me, even though I'm the world's – sorry, Solar System's – leading expert on the painless removal of elderly scientists.
   'Would you believe that I'm still slightly drunk? We felt we deserved a little party, once we'd successfully rendez – rendezvous, damn, rendezvoused with Discovery. Besides, we had two new crew members to welcome aboard. Chandra doesn't believe in alcohol – it makes you too human – but Walter Curnow more than made up for him, Only Tanya remained stone-cold sober, just as you'd expect.
   'My fellow Americans – I sound like a politician, God help me – came out of hibernation without any problems, and are both looking forward to starting work. We'll all have to move quickly; not only is time running out, but Discovery seems to be in very bad shape. We could hardly believe our eyes when we saw how its spotless white hull had turned a sickly yellow.
   'Io's to blame, of course. The ship's spiralled down to within three thousand kilometres, and every few days one of the volcanoes blasts a few megatons of sulphur up into the sky. Even though you've seen the movies, you can't really imagine what it's like to hang above that inferno; I'll be glad when we can get away, even though we'll be heading for something much more mysterious – and perhaps far more dangerous.
   'I flew over Kilauea during the '06 eruption; that was mighty scary, but it was nothing – nothing – compared to this. At the moment, we're over the nightside, and that makes it worse. You can see just enough to imagine a lot more. It's as close to Hell as I ever want to get.
   'Some of the sulphur lakes are hot enough to glow, but most of the light comes from electrical discharges. Every few minutes the whole landscape seems to explode, as if a giant photoflash has gone off above it. And that's probably not a bad analogy; there are millions of amps flowing in the flux-tube linking Io and Jupiter, and every so often there's a breakdown. Then you get the biggest lightning flash in the Solar System, and half our circuit-breakers jump out in sympathy.
   'There's just been an eruption right on the terminator, and I can see a huge cloud expanding up toward us, climbing into the sunlight. I doubt if it will reach our altitude, and even if it does it will be harmless by the time it gets here. But it looks ominous – a space monster, trying to devour us.
   'Soon after we got here, I realized that Io reminded me of something; it took me a couple of days to work it out, and then I had to check with Mission Archives because the ship's library couldn't help – shame on it. Do you remember how I introduced you to The Lord of the Rings, when we were kids back at that Oxford conference? Well, Io is Mordor: look up Part Three. There's a passage about "rivers of molten rock that wound their way... until they cooled and lay like twisted dragon-shapes vomited from the tormented earth." That's a perfect description: how did Tolkien know, a quarter century before anyone ever saw a picture of Io? Talk about Nature imitating Art.
   'At least we won't have to land there: I don't think that even our late Chinese colleagues would have attempted that. But perhaps one day it may be possible; there are areas that seem fairly stable, and not continually inundated by sulphur floods.
   'Who would have believed that we'd come all the way to Jupiter, greatest of planets – and then ignore it. Yet that's what we're doing most of the time; and when we're not looking at Io or Discovery, we're thinking about the Artifact.
   'It's still ten thousand kilometres away, up there at the libration point, but when I look at it through the main telescope it seems close enough to touch. Because it's so completely featureless, there's no indication of size, no way the eye can judge it's really a couple of kilometres long. If it's solid, it must weigh billions of tons.
   'But is it solid? It gives almost no radar echo, even when it's square-on to us. We can see it only as a black silhouette against the clouds of Jupiter, three hundred thousand kilometres below. Apart from its size, it looks exactly like the monolith we dug up on the Moon.
   'Well, tomorrow we'll go aboard Discovery, and I don't know when I'll have time or opportunity to speak to you again. But there's one more thing, old friend, before I sign off.
   'It's Caroline. She's never really understood why I had to leave Earth, and in a way I don't think she'll ever quite forgive me. Some women believe, that love isn't the only thing – but everything. Perhaps they're right... anyway, it's certainly too late to argue now.
   'Try and cheer her up when you have a chance. She talks about going back to the mainland. I'm afraid that if she does...
   'If you can't get through to her, try to cheer up Chris. I miss him more than I care to say.
   'He'll believe Uncle Dimitri – if you say that his father still loves him, and will be coming home just as quickly as he can.'

17 – Boarding Party

   Even in the best of circumstances, it is not easy to board a derelict and uncooperative spaceship. Indeed, it can be positively dangerous.
   Walter Curnow knew that as an abstract principle; but he did not really feel it in his bones until he saw the entire hundred-metre length of Discovery turning end-over-end, while Leonov kept at a safe distance. Years ago, friction had braked the spin of Discovery's carousel, thus transferring its angular momentum to the rest of the structure. Now, like a drum-majorette's baton at the height of its trajectory, the abandoned ship was slowly tumbling along its orbit.
   The first problem was to stop that spin, which made Discovery not only uncontrollable but almost unapproachable. As he suited up in the airlock with Max Brailovsky, Curnow had a very rare sensation of incompetence, even inferiority; it was not his line of business. He had already explained gloomily, 'I'm a space engineer, not a space monkey'; but the job had to be done. He alone possessed the skills that could save Discovery from Io's grasp. Max and his colleagues, working with unfamiliar circuit diagrams and equipment, would take far too long. By the time they had restored power to the ship and mastered its controls, it would have plunged into the sulphurous firepits below.
   'You're not scared, are you?' asked Max, when they were about to put on their helmets.
   'Not enough to make a mess in my suit. Otherwise, yes.' Max chuckled. 'I'd say that's about right for this job. But don't worry – I'll get you there in one piece, with my – what do you call it?'
   'Broomstick. Because witches are supposed to ride them.'
   'Oh yes. Have you ever used one?'
   'I tried once, but mine got away from me. Everyone else thought it was very funny.'
   There are some professions which have evolved unique and characteristic tools – the longshoreman's hook, the potter's wheel, the bricklayer's trowel, the geologist's hammer. The men who had to spend much of their time on zero-gravity construction projects had developed the broomstick.
   It was very simple – a hollow tube just a metre long, with a footpad at one end and a retaining loop at the other. At the touch of a button, it could telescope out to five or six times its normal length, and the internal shock-absorbing system allowed a skilled operator to perform the most amazing manoeuvres. The footpad could also become a claw or hook if necessary; there were many other refinements, but that was the basic design. It looked deceptively easy to use; it wasn't.
   The airlock pumps finished recycling; the EXIT sign came on; the outer doors opened, and they drifted slowly into the void.
   Discovery was windmilling about two hundred metres away, following them in orbit around Io, which filled half the sky. Jupiter was invisible, on the other side of the satellite. This was a matter of deliberate choice; they were using Io as a shield to protect them from the energies raging back and forth in the flux-tube that linked the two worlds. Even so, the radiation level was dangerously high; they had less than fifteen minutes before they must get back to shelter.
   Almost immediately, Curnow had a problem with his suit. 'It fitted me when I left Earth,' he complained. 'But now I'm rattling around inside like a pea in a pod.'
   'That's perfectly normal, Walter,' said Surgeon-Commander Rudenko, breaking into the radio circuit. 'You lost ten kilos in hibernation, which you could very well afford to miss. And you've already put three of them back.'
   Before Curnow had time to think of a suitable retort, he found himself gently but firmly jerked away from Leonov.
   'Just relax, Walter,' said Brailovsky. 'Don't use your thrusters, even if you start tumbling. Let me do all the work.'
   Curnow could see the faint puffs from the younger man's backpack, as its tiny jets drove them toward Discovery. With each little cloud of vapour there came a gentle tug on the towline, and he would start moving toward Brailovsky; but he never caught up with him before the next puff came. He felt rather like a yo-yo – now making one of its periodic comebacks on Earth – bouncing up and down on its string.
   There was only one safe way to approach the derelict, and that was along the axis around which it was slowly revolving. Discovery's centre of rotation was approximately amidships, near the main antenna complex, and Brailovsky was heading directly toward this area, with his anxious partner in tow. How will he stop both of us in time? Curnow asked himself.
   Discovery was now a huge, slender dumbbell slowly flailing the entire sky ahead of them. Though it took several minutes to complete one revolution, the far ends were moving at an impressive speed. Curnow tried to ignore them, and concentrated on the approaching – and immobile – centre.
   'I'm aiming for that,' said Brailovsky. 'Don't try to help, and don't be surprised at anything that happens.'
   Now, what does he mean by that? Curnow asked himself, while preparing to be as unsurprised as possible.
   Everything happened in about five seconds. Brailovsky triggered his broomstick, so that it telescoped out to its full length of four metres and made contact with the approaching ship. The broomstick started to collapse, its internal spring absorbing Brailovsky's considerable momentum; but it did not, as Curnow had fully expected, bring him to rest beside the antenna mount. It immediately expanded again, reversing the Russian's velocity so that he was, in effect, reflected away from Discovery just as rapidly as he had approached. He flashed past Curnow, heading out into space again, only a few centimetres away. The startled American just had time to glimpse a large grin before Brailovsky shot past him.
   A second later, there was a jerk on the line connecting them, and a quick surge of deceleration as they shared momentum. Their opposing velocities had been neatly cancelled; they were virtually at rest with respect to Discovery. Curnow had merely to reach out to the nearest handhold, and drag them both in.
   'Have you ever tried Russian roulette?' he asked, when he had got his breath back.
   'No – what is it?'
   'I must teach you sometime. It's almost as good as this for curing boredom.'
   'I hope you're not suggesting, Walter, that Max would do anything dangerous?'
   Dr Rudenko sounded as if she was genuinely shocked, and Curnow decided it was best not to answer; sometimes the Russians did not understand his peculiar sense of humour. 'You could have fooled me,' he muttered under his breath, not loud enough for her to hear.
   Now that they were firmly attached to the hub of the windmilling ship, he was no longer conscious of its rotation – especially when he fixed his gaze upon the metal plates immediately before his eyes. The ladder stretching away into the distance, running along the slender cylinder that was Discovery's main structure, was his next objective. The spherical command module at its far end seemed several light-years away, though he knew perfectly well that the distance was only fifty metres.
   'I'll go first,' said Brailovsky, reeling in the slack on the line linking them together. 'Remember – it's downhill all the way from here. But that's no problem – you can hold on with one hand. Even at the bottom, gravity's only about a tenth gee. And that's – what do you say? – chickenshit.'
   'I think you mean chickenfeed. And if it's all the same to you, I'm going feet first. I never liked crawling down ladders the wrong way up – even in fractional gravity.'
   It was essential, Curnow was very well aware, to keep up this gently bantering tone; otherwise he would be simply overwhelmed by the mystery and danger of the situation. There he was, almost a billion kilometres from home, about to enter the most famous derelict in the entire history of space exploration; a media reporter had once called Discovery the Marie Celeste of space, and that was not a bad analogy. But there was also much that made his situation unique; even if he tried to ignore the nightmare moonscape filling half the sky, there was a constant reminder of its presence at hand. Every time he touched the rungs of the ladder, his glove dislodged a thin mist of sulphur dust.
   Brailovsky, of course, was quite correct; the rotational gravity caused by the ship's end-over-end tumbling was easily countered. As he grew used to it, Curnow even welcomed the sense of direction it gave him.
   And then, quite suddenly, they had reached the big, discoloured sphere of Discovery's control and life-support module. Only a few metres away was an emergency hatch – the very one, Curnow realized, that Bowman had entered for his final confrontation with Hal.
   'Hope we can get in,' muttered Brailovsky. 'Pity to come all this way and find the door locked.'
   He scraped away the sulphur obscuring the AIRLOCK STATUS display panel.
   'Dead, of course. Shall I try the controls?'
   'Won't do any harm – but nothing will happen.'
   'You're right. Well, here goes with manual...
   It was fascinating to watch the narrow hairline open in the curved wall, and to note the little puff of vapour dispersing into space, carrying with it a scrap of paper. Was that some vital message? They would never know; it spun away, tumbling end over end without losing any of its initial spin as it disappeared against the stars.
   Brailovsky kept turning the manual control for what seemed a very long time, before the dark, uninviting cave of the airlock was completely open. Curnow had hoped that the emergency lights, at least, might still be operating. No such luck.
   'You're boss now, Walter. Welcome to US territory.'
   It certainly did not look very welcoming as he clambered inside, flashing the beam of his helmet light around the interior. As far as Curnow could tell, everything was in good order. What else had he expected? he asked himself, half angrily.
   Closing the door manually took even longer than opening it, but there was no alternative until the ship was powered up again. Just before the hatch was sealed, Curnow risked a glance at the insane panorama outside.
   A flickering blue lake had opened up near the equator; he was sure it had not been there a few hours earlier. Brilliant yellow flares, the characteristic colour of glowing sodium, were dancing along its edges; and the whole of the nightland was veiled in the ghostly plasma discharge of one of Io's almost continuous auroras.
   It was the stuff of future nightmares – and as if that was not sufficient, there was one further touch worthy of a mad surrealist artist. Stabbing up into the black sky, apparently emerging directly from the firepits of the burning moon, was an immense, curving horn, such as a doomed bullfighter might have glimpsed in the final moment of truth.
   The crescent of Jupiter was rising to greet Discovery and Leonov as they swept toward it along their common orbit.

18 – Salvage

   The moment that the outer hatch had closed behind them, there had been a subtle reversal of roles. Curnow was at home now, while Brailovsky was out of his element, feeling ill at ease in the labyrinth of pitch-black corridors and tunnels that was Discovery's interior. In theory, Max knew his way round the ship, but that knowledge was based only on a study of its design drawings. Curnow, on the other hand, had spent months working in Discovery's still uncompleted identical twin; he could, quite literally, find his way around blindfolded.
   Progress was made difficult because that part of the ship was designed for zero gee; now the uncontrolled spin provided an artificial gravity, which, slight though it was, always seemed to be in the most inconvenient direction.
   'First thing we've got to do,' muttered Curnow, after sliding several metres down a corridor before he could grab a handhold, 'is to stop this damned spin. And we can't do that until we have power. I only hope that Dave Bowman safeguarded all systems before he abandoned ship.'
   'Are you sure he did abandon the ship? He may have intended to come back.'
   'You may be right; I don't suppose we'll ever know. If he even knew himself.'
   They had now entered the Pod Bay – Discovery's 'space garage', which normally contained three of the spherical one-man modules used for activities outside the ship. Only Pod Number 3 remained; Number 1 had been lost in the mysterious accident that had killed Frank Poole – and Number 2 was with Dave Bowman, wherever he might be.
   The Pod Bay also contained two spacesuits, looking uncomfortably like decapitated corpses as they hung helmet-less in their racks. It needed very little effort of the imagination – and Brailovsky's was now working overtime – to fill them with a whole menagerie of sinister occupants.
   It was unfortunate, but not altogether surprising, that Curnow's sometimes irresponsible sense of humour got the better of him at this very moment.
   'Max,' he said, in a tone of deadly seriousness, 'whatever happens – please don't go chasing off after the ship's cat.'
   For a few milliseconds, Brailovsky was thrown off guard; he almost answered: 'I do wish you hadn't said that, Walter', but checked himself in time. That would have been too damning an admission of weakness; instead he replied, 'I'd like to meet the idiot who put that movie in our library.'
   'Katerina probably did it, to test everyone's psychological balance. Anyway, you laughed your head off when we screened it last week.'
   Brailovsky was silent; Curnow's remark was perfectly true. But that had been back in the familiar warmth and light of Leonov, among his friends – not in a pitch-black, freezing derelict, haunted by ghosts. No matter how rational one was, it was all too easy to imagine some implacable alien beast prowling these corridors, seeking whom it might devour.
   It's all your fault, Grandma (may the Siberian tundra lie lightly on your beloved bones) – I wish you hadn't filled my mind with so many of those gruesome legends. If I close my eyes, I can still see the hut of the Baba Yaga, standing in that forest clearing on its scrawny chicken legs...
   Enough of this nonsense. I'm a brilliant young engineer faced with the biggest technical challenge of his life, and I mustn't let my American friend know that I'm sometimes a frightened little boy.
   The noises did not help. There were too many of them, though they were so faint that only an experienced astronaut would have detected them against the sounds of his own suit. But to Max Brailovsky, accustomed to working in an environment of utter silence, they were distinctly unnerving, even though he knew that the occasional cracklings and creakings were almost certainly caused by thermal expansion as the ship turned like a roast on a spit. Feeble though the sun was out here, there was still an appreciable temperature change between light and shade.
   Even his familiar spacesuit felt wrong, now that there was pressure outside as well as in. All the forces acting on its joints were subtly altered, and he could no longer judge his movements accurately. I'm a beginner, starting my training all over again, he told himself angrily. Time to break the mood by some decisive action.
   'Walter – I'd like to test the atmosphere.'
   'Pressure's okay; temperature – phew – it's one hundred five below zero.'
   'A nice bracing Russian winter. Anyway, the air in my suit will keep out the worst of the cold.'
   'Well, go ahead. But let me shine my light on your face, so I can see if you start to turn blue. And keep talking.'
   Brailovsky unsealed his visor and swung the faceplate upward. He flinched momentarily as icy fingers seemed to caress his cheeks, then took a cautious sniff, followed by a deeper breath.
   'Chilly – but my lungs aren't freezing. There's a funny smell, though. Stale, rotten – as if something's – oh no!'
   Looking suddenly pale, Brailovsky quickly snapped the faceplate shut.
   'What's the trouble, Max?' Curnow asked with sudden and now perfectly genuine anxiety. Brailovsky did not reply; he looked as if he was still trying to regain control of himself. Indeed, he seemed in real danger of that always horrible and sometimes fatal disaster – vomiting in a spacesuit.
   There was a long silence; then Curnow said reassuringly:
   'I get it. But I'm sure you're wrong. We know that Poole was lost in space. Bowman reported that he... ejected the others after they died in hibernation – and we can be sure that he did. There can't be anyone here. Besides, it's so cold.' He almost added 'like a morgue' but checked himself in time.
   'But' suppose,' whispered Brailovsky, 'just suppose Bowman managed to get back to the ship – and died here.'
   There was an even longer silence before Curnow deliberately and slowly opened his own faceplate. He winced as the freezing air bit into his lungs, then wrinkled his nose in disgust.
   'I see what you mean. But you're letting your imagination run away with you. I'll bet you ten to one that smell comes from the galley. Probably some meat went bad, before the ship froze up. And Bowman must have been too busy to be a good housekeeper. I've known bachelor apartments that smelled as bad as this.'
   'Maybe you're right. I hope you are.'
   'Of course I am. And even if I'm not – dammit, what difference does it make? We've got a job to do, Max. If Dave Bowman's still here, that's not our department – is it, Katerina?'
   There was no reply from the Surgeon-Commander; they had gone too far inside the ship for radio to penetrate. They were indeed on their own, but Max's spirits were rapidly reviving. It was a privilege, he decided, to work with Walter. The American engineer sometimes appeared soft and easygoing. But he was totally competent – and, when necessary, as hard as nails.
   Together, they would bring Discovery back to life; and, perhaps, back to Earth.

19 – Operation WINDMILL

   When Discovery suddenly lit up like the proverbial Christmas tree, navigation and interior lights blazing from end to end, the cheer aboard Leonov might almost have been heard across the vacuum between the two ships. It turned into an ironic groan when the lights promptly went out again.
   Nothing else happened for half an hour; then the observation windows of Discovery's flight deck began to glow with the soft crimson of the emergency lights. A few minutes later, Curnow and Brailovsky could be seen moving around inside, their figures blurred by the film of sulphur dust.
   'Hello, Max – Walter – can you hear us?' called Tanya Orlova. Both the figures waved instantly, but made no other reply. Obviously, they were too busy to engage in casual conversation; the watchers on Leonov had to wait patiently while various lights flashed on and off, one of the three Pod Bay doors slowly opened and quickly closed, and the main antenna slewed around a modest ten degrees.
   'Hello, Leonov,' said Curnow at last. 'Sorry to keep you waiting, but we've been rather busy.
   'Here's a quick assessment, judging from what we've seen so far. The ship's in much better shape than I feared. Hull's intact, leakage negligible – air pressure eighty-five per cent nominal. Quite breathable, but we'll have to do a major recycling job because it stinks to high heaven.
   'The best news is that the power systems are okay. Main reactor stable, batteries in good shape. Almost all the circuit-breakers were open – they'd jumped or been thrown by Bowman before he left – so all vital equipment's been safeguarded. But it will be a very big job checking everything before we have full power again.'
   'How long will that take – at least for the essential systems: life-support, propulsion?'
   'Hard to say, skipper. How long before we crash?'
   'Minimum present prediction is ten days. But you know how that's changed up – and down.'
   'Well, if we don't run into any major snags, we can haul Discovery up to a stable orbit away from this hellhole – oh, I'd say inside a week.'
   'Anything you need?'
   'No – Max and I are doing fine. We're going into the carousel now, to check the bearings. I want to get it running as soon as possible.'
   'Pardon me, Walter – but is that important? Gravity's convenient, but we've managed without any for quite a while.'
   'I'm not after gravity, though it will be useful to have some aboard. If we can get the carousel running again, it will mop up the ship's spin – stop it tumbling. Then we'll be able to couple our airlocks together, and cut out EVAs. That will make work a hundred times easier.'
   'Nice idea, Walter – but you're not going to mate my ship to that... windmill. Suppose the bearings seize up and the carousel jams? That would tear us to pieces.'
   'Agreed. We'll cross that bridge when we come to it. I'll report again as soon as I can.'
   No one had much rest for the next two days. By the end of that time, Curnow and Brailovsky had practically fallen asleep in their suits, but had completed their survey of Discovery and found no unpleasant surprises. Both the Space Agency and the State Department were relieved by the preliminary report; it allowed them to claim, with some justification, that Discovery was not a derelict but a 'temporarily decommissioned United States Spacecraft'. Now the task of reconditioning had to begin.
   Once power had been restored, the next problem was the air; even the most thorough housecleaning operations had failed to remove the stink. Curnow had been right in identifying its source as food spoiled when refrigeration had failed; he also claimed, with mock seriousness, that it was quite romantic. 'I've only got to close my eyes,' he asserted, 'and I feel I'm back on an old-time whaling ship. Can you imagine what the Pequod must have smelled like?'
   It was unanimously agreed that, after a visit to Discovery, very little effort of the imagination was required. The problem was finally solved – or at least reduced to manageable proportions – by dumping the ship's atmosphere. Fortunately, there was still enough air in the reserve tanks to replace it.
   One piece of very welcome news was that ninety per cent of the propellant needed for the return journey was still available; choosing ammonia instead of hydrogen as working fluid for the plasma drive had paid off handsomely. The more efficient hydrogen would have boiled off into space years ago, despite the insulation of the tanks and the frigid temperature outside. But almost all the ammonia had remained safely liquified, and there was enough to get the ship back to a safe orbit around the Earth. Or at least around the Moon.
   Checking Discovery's propellerlike spin was perhaps the most critical step in getting the ship under control. Sasha Kovalev compared Curnow and Brailovsky to Don Quixote and Sancho Panza, and expressed the hope that their windmill-tilting expedition would end more successfully.
   Very cautiously, with many pauses for checking, power was fed to the carousel motors and the great drum was brought up to speed, reabsorbing the spin it had long ago imparted to the ship. Discovery executed a complex series of precessions, until eventually its end-over-end tumble had almost vanished. The last traces of unwanted rotation were neutralized by the attitude-control jets, until the two ships were floating motionless side by side, the squat, stocky Leonov dwarfed by the long, slender Discovery.
   Transfer from one to the other was now safe and easy, but Captain Orlova still refused to permit a physical linkup. Everyone agreed with this decision, for Io was coming steadily closer; they might yet have to abandon the vessel they had worked so hard to save.
   The fact that they now knew the reason for Discovery's mysterious orbital decay did not help in the least. Every time the ship passed between Jupiter and Io, it sliced through the invisible flux-tube linking the two bodies – the electric river flowing from world to world. The resulting eddy currents induced in the ship were continually slowing it down, braking it once every revolution.
   There was no way to predict the final moment of impact, for the current in the flux-tube varied wildly according to Jupiter's own inscrutable laws. Sometimes there were dramatic surges of activity accompanied by spectacular electric and auroral storms around Io. Then the ships would lose altitude by many kilometres, at the same time becoming uncomfortably hot before their thermal control systems could readjust.
   This unexpected effect had scared and surprised everyone before the obvious explanation was realized. Any form of braking produces heat, somewhere; the heavy currents induced in the hulls of Leonov and Discovery turned them briefly into low-powered electric furnaces. It was not surprising that some of Discovery's food supply had been ruined during the years the ship had been alternately cooked and cooled.
   The festering landscape of Io, looking more than ever like an illustration from a medical textbook, was only five hundred kilometres away when Curnow risked activating the main drive, while Leonov stood off at a very respectful distance. There were no visible effects – none of the smoke and fire of the old-time chemical rockets – but the two ships drew slowly apart as Discovery gained speed. After a few hours of very gentle manoeuvring, both ships had raised themselves a thousand kilometres; now there was time to relax briefly, and to make plans for the next stage in the mission.
   'You've done a wonderful job, Walter,' said Surgeon-Commander Rudenko, putting her ample arm around the exhausted Curnow's shoulders. 'We're all proud of you.'
   Very casually, she broke a small capsule under his nose. It was twenty-four hours before he woke up, annoyed and hungry.

20 – Guillotine

   'What is it?' asked Curnow with mild distaste, hefting the little mechanism in his hand. 'A guillotine for mice?'
   'Not a bad description – but I'm after bigger game.' Floyd pointed to a flashing arrow on the display screen, which was now showing a complicated circuit diagram.
   'You see this line?'
   'Yes – the main power supply. So?'
   'This is the point where it enters Hal's central processing unit. I'd like you to install this gadget here. Inside the cable trunking, where it can't be found without a deliberate search.'
   'I see. A remote control, so you can pull the plug on Hal whenever you want to. Very neat – and a non-conducting blade, too, so there won't be any embarrassing shorts when it's triggered. Who makes toys like this? The CIA?'
   'Never mind. The control's in my room – that little red calculator I always keep on my desk. Put in nine nines, take the square root, and press TNT. That's all. I'm not sure of its range – we'll have to test that – but as long as Leonov and Discovery are within a couple of kilometres of each other, there'll be no danger of Hal running amok again.'
   'Who are you going to tell about this... thing?'
   'Well, the only person I'm really hiding it from is Chandra.'
   'I guessed as much.'
   'But the fewer who know, the less likely it is to be talked about. I'll tell Tanya that it exists, and if there's an emergency you can show her how to operate it.'
   'What kind of emergency?'
   'That's not a very bright question, Walter. If I knew, I wouldn't need the damn thing.'
   'Guess you're right. When do you want me to install your patented Hal-zapper?'
   'As soon as you can. Preferably tonight. When Chandra's sleeping.'
   'Are you kidding? I don't think he ever sleeps. He's like a mother nursing a sick baby.'
   'Well, he's got to come back to Leonov to eat, occasionally.'
   'I've news for you. The last time he went across, he tied a little sack of rice to his suit. That will keep him going for weeks.'
   'Then we'll have to use one of Katerina's famous knockout drops. They did a pretty good job on you, didn't they?'
   Curnow was joking about Chandra – at least, Floyd assumed that he was, though one could never be quite sure: he was fond of making outrageous statements with a perfectly straight face. It had been some time before the Russians had fully realized that; soon, in self-defence, they were prone to pre-emptive laughs even when Curnow was being perfectly serious.
   Curnow's own laugh, mercifully, had much abated since Floyd had first heard it in the upward-bound shuttle; on that occasion, it had obviously been primed by alcohol. He had fully expected to cringe from it again at the end-of-orbit party, when Leonov had finally made rendezvous with Discovery. But even on that occasion, though Curnow had drunk a good deal, he had remained as much under control as Captain Orlova herself.
   The one thing he did take seriously was his work. On the way up from Earth, he had been a passenger. Now he was crew.

21 – Resurrection

   We are, Floyd told himself, about to awaken a sleeping giant. How will Hal react to our presence, after all these years? What will he remember of the past – and will he be friendly, or hostile?
   As he floated just behind Dr Chandra in the zero-gravity environment of Discovery's flight deck, Floyd's mind was seldom far from the cut-off switch, installed and tested only a few hours earlier. The radio control was mere centimetres from his hand, and he felt somewhat foolish to have brought it with him. At this stage, Hal was still disconnected from all the ship's operational circuits. Even if he was reactivated, he would be a brain without limbs though not without sense organs. He would be able to communicate, but not to act. As Curnow had put it, 'The worst he can do is swear at us.'
   'I'm ready for the first test, Captain,' said Chandra. 'All the missing modules have been replaced, and I've run diagnostic programs on all circuits. Everything appears normal, at least on this level.'
   Captain Orlova glanced at Floyd, who gave a nod. At Chandra's insistence, only the three of them were present for this critical first run, and it was quite obvious that even this small audience was unwelcome.
   'Very well, Dr Chandra.' Ever conscious of protocol, the captain added quickly: 'Dr Floyd has given his approval, and I have no objections myself.'
   'I should explain,' said Chandra, in a tone that clearly conveyed disapproval, 'that his voice-recognition and speech-synthesis centres have been damaged. We'll have to teach him to speak all over again. Luckily, he learns several million times faster than a human being.'
   The scientist's fingers danced over the keyboard as he typed out a dozen words, apparently at random, carefully pronouncing each one as it appeared on the screen. Like a distorted echo, the words came back from the speaker grille – lifeless, indeed mechanical, with no sense of any intelligence behind them. This isn't the old Hal, thought Floyd. It's no better than the primitive speaking toys that were such a novelty when I was a kid.
   Chandra pressed the REPEAT button, and the series of words sounded once again. Already, there was a noticeable improvement, though no one could have mistaken the speaker for a human being.
   'The words I gave him contain the basic English phonemes; about ten iterations, and he'll be acceptable. But I don't have the equipment to do a really good job of therapy.'
   'Therapy?' asked Floyd. 'You mean that 'he's – well, brain-damaged?'
   'No,' snapped Chandra. 'The logic circuits are in perfect condition. Only the voice output may be defective, though it will improve steadily. So check everything against the visual display, to avoid misinterpretations. And when you do speak, enunciate carefully.'
   Floyd gave Captain Orlova a wry smile, and asked the obvious question.
   'What about all the Russian accents around here?'
   'I'm sure that won't be a problem with Captain Orlova and Dr Kovalev. But with the others – well, we'll have to run individual tests. Anyone who can't pass will have to use the keyboard.'
   'That's still looking a long way ahead. For the present, you're the only person who should attempt communication. Agreed, Captain?'
   'Absolutely.'
   Only the briefest of nods revealed that Dr Chandra had heard them. His fingers continued to fly over the keyboard, and columns of words and symbols flashed across the display screen at such a rate that no human being could possibly assimilate them. Presumably Chandra had an eidetic memory, for he appeared to recognize whole pages of information at a glance.
   Floyd and Orlova were just about to leave the scientist to his arcane devotions when he suddenly acknowledged their presence again, holding up his hand in warning or anticipation. With an almost hesitant movement, in marked contrast with his previous swift actions, he slid back a locking bar and pressed a single, isolated key.
   Instantly, with no perceptible pause, a voice came from the console, no longer in a mechanical parody of human speech. There was intelligence – consciousness – self-awareness here, though as yet only on a rudimentary level.
   'Good morning, Dr Chandra, This is Hal. I am ready for my first lesson.'
   There was a moment of shocked silence; then, acting on the same impulse, the two observers left the deck.
   Heywood Floyd would never have believed it. Dr Chandra was crying.

IV – LAGRANGE

22 – Big Brother

   '... What delightful news about the baby dolphin! I can just imagine how excited Chris was when the proud parents brought it into the house. You should have heard the ohs and ahs of my shipmates when they saw the videos of them swimming together, and Chris riding on its back. They suggest we call it Sputnik, which means companion as well as satellite.
   'Sorry it's been quite a while since my last message, but the newscasts will have given you an idea of the huge job we've had to do. Even Captain Tanya's given up all pretence of a regular schedule; each problem has to be fixed as it comes along, by whoever is on the spot. We sleep when we can't stay awake any longer.
   'I think we can all be proud of what we've done. Both ships are operational and we've nearly finished our first round of tests on Hal. In a couple of days we'll know if we can trust him to fly Discovery when we leave here to make our final rendezvous with Big Brother.
   'I don't know who first gave it that name – the Russians, understandably, aren't keen on it. And they've waxed quite sarcastic about our official designation TMA-2, pointing out to me – several times – that it's the best part of a billion kilometres from Tycho. Also that Bowman reported no magnetic anomaly, and that the only resemblance to TMA-1 is the shape. When I asked them what name they preferred, they came up with Zagadka, which means enigma. It's certainly an excellent name; but everyone smiles when I try to pronounce it, so I'll stick to Big Brother.
   'Whatever you call the thing, it's only ten thousand kilometres away now, and the trip won't take more than a few hours. But that last lap has us all nervous, I don't mind telling you.
   'We'd hoped that we might find some new information aboard Discovery. That's been our only disappointment, though we should have expected it. Hal, of course, was disconnected long before the encounter, and so has no memories of what happened; Bowman has taken all his secrets with him. There's nothing in the ship's log and automatic recording systems that we didn't already know.
   'The only new item we discovered was purely personal – a message that Bowman had left for his mother. I wonder why he never sent it; obviously, he did expect – or hope – to return to the ship after that last EVA. Of course, we've had it forwarded to Mrs Bowman – she's in a nursing home, somewhere in Florida, and her mental condition is poor, so it may not mean anything to her.
   'Well, that's all the news this time. I can't tell you how much I miss you... and the blue skies and green seas of Earth. All the colours here are reds and oranges and yellows – often as beautiful as the most fantastic sunset, but after a while one grows sick for the cool, pure rays at the other end of the spectrum.
   'My love to you both – I'll call again just as soon as I can.'

23 – Rendezvous

   Nikolai Temovsky, Leonov's control and cybernetics expert, was the only man aboard who could talk to Dr Chandra on something like his own terms. Although Hal's principal creator and mentor was reluctant to admit anyone into his full confidence, sheer physical exhaustion had forced him to accept help. Russian and Indo-American had formed a temporary alliance, which functioned surprisingly well. Most of the credit for this went to the good-natured Nikolai, who was somehow able to sense when Chandra really needed him, and when he preferred to be alone. The fact that Nikolai's English was much the worst on the ship was totally unimportant, since most of the time both men spoke a computerese wholly unintelligible to anyone else.
   After a week's slow and careful reintegration, all of Hal's routine, supervisory functions were operating reliably. He was like a man who could walk, carry out simple orders, do unskilled jobs, and engage in low-level conversation. In human terms, he had an Intelligence Quotient of perhaps 50; only the faintest outlines of his original personality had yet emerged.
   He was still sleepwalking; nevertheless, in Chandra's expert opinion, he was now quite capable of flying Discovery from its close orbit around Io up to the rendezvous with Big Brother.
   The prospect of getting an extra seven thousand kilometres away from the burning hell beneath them was welcomed by everyone. Trivial though that distance was in astronomical terms, it meant that the sky would no longet be dominated by a landscape that might have been imagined by Dante or Hieronymus Bosch. And although not even the most violent eruptions had blasted any material up to the ships, there was always the fear that Io might attempt to set a new record. As it was, visibility from Leonov's observation deck was steadily degraded by a thin film of sulphur, and sooner or later someone would have to go out and clean it off.
   Only Curnow and Chandra were aboard Discovery when Hal was given the first control of the ship. It was a very limited form of control; he was merely repeating the program that had been fed into his memory, and monitoring its execution. And the human crew was monitoring him: if any malfunction occurred, they would take over immediately.
   The first burn lasted for ten minutes; then Hal reported that Discovery had entered the transfer orbit. As soon as Leonov's radar and optical tracking confirmed that, the other ship injected itself into the same trajectory. Two minor in-course corrections were made; then, three hours and fifteen minutes later, both arrived uneventfully at the first Lagrange point, L. 1 – 10,500 kilometres up, on the invisible line connecting the centres of Io and Jupiter.
   Hal had behaved impeccably, and Chandra showed unmistakable traces of such purely human emotions as satisfaction and even joy. But by that time, everyone's thoughts were elsewhere; Big Brother, alias Zagadka, was only a hundred kilometres away.
   Even from that distance, it already appeared larger than the Moon as seen from Earth, and shockingly unnatural in its straight-edged, geometrical perfection. Against the background of space it would have been completely invisible, but the scudding Jovian clouds 350,000 kilometres below showed it up in dramatic relief. They also produced an illusion that, once experienced, the mind found almost impossible to refute. Because there was no way in which its real location could be judged by the eye, Big Brother often looked like a yawning trapdoor set in the face of Jupiter.
   There was no reason to suppose that a hundred kilometres would be 'safer than ten, or more dangerous than a thousand; it merely seemed psychologically right for a first reconnaissance. From that distance, the ship's telescopes could have revealed details only centimetres across -but there were none to be seen. Big Brother appeared completely featureless; which, for an object that had, presumably, survived millions of years of bombardment by space debris, was incredible.
   When Floyd stared through the binocular eyepiece, it seemed to him that he could reach out and touch those smooth, ebon surfaces – just as he had done on the Moon, years ago. That first time, it had been with the gloved hand of his spacesuit. Not until the Tycho monolith had been enclosed in a pressurized dome had he been able to use his naked hand.
   That had made no difference; he did not feel that he had ever really touched TMA-1. The tips of his fingers had seemed to skitter over an invisible barrier, and the harder he pushed, the greater the repulsion grew. He wondered if Big Brother would produce the same effect.
   Yet before they came that close, they had to make every test they could devise and report their observations to Earth. They were in much the same position as explosives experts trying to defuse a new type of bomb, which might be detonated by the slightest false move. For all that they could tell, even the most delicate of radar probes might trigger some unimaginable catastrophe.
   For the first twenty-four hours, they did nothing except observe with passive instruments – telescopes, cameras, sensors on every wavelength. Vasili Orlov also took the opportunity of measuring the slab's dimensions with the greatest possible precision, and confirmed the famous 1:4:9 ratio to six decimal places. Big Brother was exactly the same shape as TMA-1 – but as it was more than two kilometres long, it was 718 times larger than its small sibling.
   And there was a second mathematical mystery. Men had been arguing for years over that 1:4:9 ratio – the squares of the first three integers. That could not possibly be a coincidence; now here was another number to conjure with.
   Back on Earth, statisticians and mathematical physicists were soon playing happily with their computers, trying to relate the ratio to the fundamental constants of nature – the velocity of light, the proton/electron mass ratio, the fine-structure constant. They were quickly joined by a gaggle of numerologists, astrologers, and mystics, who threw in the height of the Great Pyramid, the diameter of Stonehenge, the azimuth bearings of the Nazca lines, the latitude of Easter Island, and a host of other factors from which they were able to draw the most amazing conclusions about the future. They were not in the least deterred when a celebrated Washington humorist claimed that his calculations proved that the world ended on 31 December 1999 – but that everyone had had too much of a hangover to notice.
   Nor did Big Brother appear to notice the two ships that had arrived in its vicinity – even when they cautiously probed it with radar beams and bombarded it with strings of radio pulses which, it was hoped, would encourage any intelligent listener to answer in the same fashion.
   After two frustrating days, with the approval of Mission Control, the ships halved their distance. From fifty kilometres, the largest face of the slab appeared about four times the width of the Moon in Earth's sky – impressive, but not so large as to be psychologically overwhelming. It could not yet compete with Jupiter, ten times larger still; and already the mood of the expedition was changing from awed alertness to a certain impatience.
   Walter Curnow spoke for almost everyone: 'Big Brother may be willing to wait a few million years – we'd like to get away a little sooner.'

24 – Reconnaissance

   Discovery had left Earth with three of the little space pods that allowed an astronaut to perform extravehicular activities in shirt-sleeve comfort. One had been lost in the accident – if it was an accident – that had killed Frank Poole. Another had carried Dave Bowman to his final appointment with Big Brother, and shared whatever fate befell him, A third was still in the ship's garage, the Pod Bay.
   It lacked one important component – the hatch, blown off by Commander Bowman when he had made his hazardous vacuum-crossing and entered the ship through the emergency airlock, after Hal had refused to open the Pod Bay door. The resulting blast of air had rocketed the pod several hundred kilometres away before Bowman, busy with more important matters, had brought it back under radio control. It was not surprising that he had never bothered to replace the missing hatch.
   Now Pod Number 3 (on which Max, refusing all explanations, had stencilled the name Nina) was being prepared for another EVA. It still lacked a hatch, but that was unimportant. No one would be riding inside.
   Bowman's devotion to duty was a piece of unexpected luck, and it would have been folly not to take advantage of it. By using Nina as a robot probe, Big Brother could be examined at close quarters without risking human lives. That at least was the theory; no one could rule out the possibility of a backlash that might engulf the ship. After all, fifty kilometres was not even a hair's breadth, as cosmic distances went.
   After years of neglect, Nina looked distinctly shabby. The dust that was always floating around in zero gee had settled over the outer surface, so that the once immaculately white hull had become a dingy grey. As it slowly accelerated away from the ship, its external manipulators folded neatly back and its oval viewport staring spaceward like a huge, dead eye, it did not seem a very impressive ambassador of Mankind. But that was a distinct advantage; so humble an emissary might be tolerated, and its small size and low velocity should emphasize its peaceful intentions. There had been a suggestion that it should approach Big Brother with open hands; the idea was quickly turned down when almost everyone agreed that if they saw Nina heading toward them, mechanical claws outstretched, they would run for their lives.
   After a leisurely two-hour trip, Nina came to rest a hundred metres from one corner of the huge rectangular slab. From so close at hand, there was no sense of its true shape; the TV cameras might have been looking down on the tip of a black tetrahedron of indefinite size. The onboard instruments showed no sign of radioactivity or magnetic fields; nothing whatsoever was coming from Big Brother except the tiny fraction of sunlight it condescended to reflect.
   After five minutes' pause – the equivalent, it was intended, of 'Hello, here I am!' – Nina started a diagonal crossing of the smaller face, then the next larger, and finally the largest, keeping at a distance of about fifty metres, but occasionally coming in to five. Whatever the separation, Big Brother looked exactly the same – smooth and featureless. Long before the mission was completed, it had become boring, and the spectators on both ships had gone back to their various jobs, only glancing at the monitors from time to time.
   'That's it,' said Walter Curnow at last, when Nina had arrived back where she had started. 'We could spend the rest of our lives doing this, without learning anything more. What do I do with Nina – bring her home?'
   'No,' said Vasili, breaking into the circuit from aboard Leonov. 'I've a suggestion. Take her to the exact centre of the big face. Bring her to rest – oh, a hundred metres away. And leave her parked there, with the radar switched to maximum precision.'
   'No problem – except that there's bound to be some residual drift. But what's the point?'
   'I've just remembered an exercise from one of my college astronomy courses – the gravitational attraction of an infinite flat plate. I never thought I'd have a chance of using it in real life. After I've studied Nina's movements for a few hours, at least I'll be able to calculate Zagadka's mass, That is, if it has any. I'm beginning to think there's nothing really there.'
   'There's an easy way to settle that, and we'll have to do it eventually. Nina must go in and touch the thing.'
   'She already has.'
   'What do you mean?' asked Curnow, rather indignantly. 'I never got nearer than five metres.'
   'I'm not criticizing your driving skills – though it was a pretty close thing at that first corner, wasn't it? But you've been tapping gently on Zagadka every time you use Nina's thrusters near its surface.'
   'A flea jumping on an elephant!'
   'Perhaps. We simply don't know. But we'd better assume that, one way or another, it's aware of our presence, and will only tolerate us as long as we aren't a nuisance.'
   He left the unspoken question hanging in the air. How did one annoy a two-kilometre-long black rectangular slab? And just what form would its disapproval take?