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?
25
The View from Lagrange
Astronomy was full of such intriguing but meaningless coincidences. The most famous was the fact that, from the Earth, both Sun and Moon have the same apparent diameter. Here at the L.1 libration point, which Big Brother had chosen for its cosmic balancing act on the gravitational tightrope between Jupiter and Io, a similar phenomenon occurred. Planet and satellite appeared exactly the same size.
And what a size! Not the miserable half-degree of Sun and Moon, but forty times their diameter – sixteen hundred times their area. ‘The sight of either was enough to fill the mind with awe and wonder; together, the spectacle was overwhelming.
Every forty-two hours, they would go through their complete cycle of phases; when Io was new, Jupiter was full, and vice versa. But even when the Sun was hiding behind Jupiter and the planet presented only its nightside, it was unmistakably there – a huge black disk eclipsing the stars. Sometimes that blackness would be momentarily rent by lightning flashes lasting for many seconds, from electrical storms far larger than the Earth.
On the opposite side of the sky, always keeping the same face toward its giant master, Io would be a sluggishly boiling cauldron of reds and oranges, with occasional yellow clouds erupting from one of its volcanoes, and falling swiftly back to the surface. Like Jupiter, but on a slightly longer time scale, Io was a world without geography. Its face was remodelled in a matter of decades – Jupiter’s, in a matter of days.
As Io waned toward its last quarter, so the vast, intricately banded Jovian cloudscape would light up beneath the tiny, distant sun. Sometimes the shadow of Io itself, or one of the outer satellites, would drift across the face of Jupiter; while every revolution would show the planet-sized vortex of the Great Red Spot – a hurricane that had endured for centuries if not for millennia.
Poised between such wonders, the crew of Leonov had material for lifetimes of research – but the natural objects of the Jovian system were at the very bottom of their list of priorities. Big Brother was Number 1; though the ships had now moved in to only five kilometres, Tanya still refused to allow any direct physical contact. ‘I’m going to wait,’ she said, ‘until we’re in a position to make a quick getaway. We’ll sit and watch – until our launch window opens. Then we’ll consider our next move.’
It was true that Nina had finally grounded on Big Brother, after a leisurely fifty-minute fall. This had allowed Vasili to calculate the object’s mass as a surprisingly low 950,000 tons, which gave it about the density of air. Presumably it was hollow – which provoked endless speculation about what might be inside.
But there were plenty of practical, everyday problems to take their minds off these greater issues. Housekeeping chores aboard Leonov and Discovery absorbed ninety per cent of their working time, though operations’ were much more efficient since the two ships had been coupled by a flexible docking connection. Curnow had finally convinced Tanya that Discovery’s carousel would not suddenly seize up and tear the ships to pieces, so it had become possible to move freely from one vessel to the other merely by opening and closing two sets of airtight doors. Spacesuits and time-consuming EVAs were no longer necessary – to the great delight of everyone except Max, who loved going outside and exercising with his broomstick.
The two crew members quite unaffected by this were Chandra and Ternovsky, who now virtually lived aboard Discovery and worked around the clock, continuing their apparently endless dialogue with Hal. ‘When will you be ready?’ they were asked at least once a day. They refused to make any promises; Hal remained a low-grade moron.
Then, a week after the rendezvous with Big Brother, Chandra unexpectedly announced: ‘We’re ready.’
Only the two lady medics were absent from Discovery’s flight deck, and that was merely because there was no room for them; they were watching on Leonov’s monitors. Floyd stood immediately behind Chandra, his hand never far from what Curnow, with his usual gift for the neat phrase, had called his pocket giant-killer.
‘Let me emphasize again,’ said Chandra, ‘that there must be no talking. Your accents will confuse him; I can speak, but no one else. Is that understood?’
Chandra looked, and sounded, at the edge of exhaustion. Yet his voice held a note of authority that no one had ever heard before. Tanya might be the boss everywhere else, but he was master there.
The audience – some anchored to convenient handholds, some floating freely – nodded assent. Chandra closed an audio switch and said, quietly but clearly: ‘Good morning, Hal.’
An instant later, it seemed to Floyd that the years had rolled away. It was no longer a simple electronic toy that answered back. Hal had returned.
‘Good morning, Dr Chandra.’
‘Do you feel capable of resuming your duties?’
‘Of course. I am completely operational and all my circuits are functioning perfectly.’
‘Then do you mind if I ask you a few questions?’
‘Not at all.’
‘Do you recall a failure of the AE 35 antenna control unit?’
‘Certainly not.’
Despite Chandra’s injunction, there was a little gasp from the listeners. This is like tiptoeing through a minefield, thought Floyd, as he patted the reassuring shape of the radio cut-off. If that line of questioning triggered another psychosis, he could kill Hal in a second. (He knew, having rehearsed the procedure a dozen times.) But a second was aeons to a computer; that was a chance they would have to take.
‘You do not remember either Dave Bowman or Frank Poole going out to replace the AE 35 unit?’
‘No. That could not have happened, or I would have remembered it. Where are Frank and Dave? Who are these people? I can only identify you – though I compute a sixty-five per cent probability that the man behind you is Dr Heywood Floyd.’
Remembering Chandra’s strict injunction, Floyd refrained from congratulating Hal. After a decade, sixty-five per cent was a pretty good score. Many humans would not have done so well.
‘Don’t worry, Hal – I will explain everything later.’
‘Has the mission been completed? You know I have the greatest enthusiasm for it.’
‘The mission has been completed; you have carried out your program. Now – if you will excuse us – we wish to have a private conversation.’
‘Certainly.’
Chandra switched off sound and vision inputs to the main console. As far as this part of the ship was concerned, Hal was now deaf and blind.