Poole was still shaken, and it was several seconds before he could reply.

'The face and the voice were Bowman's – I'd swear to that. But what was it?'

'That's what we're still arguing about. Call it a hologram, a projection – of course, there are plenty of ways it could be faked if anyone wanted to – but not in those circumstances! And then, of course, there's what happened next.'

'Lucifer?'

'Yes. Thanks to that warning, the Leonov had just sufficient time to get away before Jupiter detonated.'

'So whatever it was, the Bowman-thing was friendly and trying to help.'

'Presumably. And it may have been responsible for that "one more message" we did receive – it was sent only minutes before the detonation. Another waning.'

Dr Kim brought the screen to life once more. It showed plain text: ALL THESE WORLDS ARE YOURS EXCEPT EUROPA. ATTEMPT NO LANDINGS THERE. The same message was repeated about a hundred times, then the letters became garbled.

'And we never have tried to land there?' asked Poole.

'Only once, by accident, thirty-six years later – when the USSS Galaxy was hijacked and forced down there, and her sister ship Universe had to go to the rescue. It's all here -with what little our robot monitors have told us about the Europans.'

'I'm anxious to see them.'

'They're amphibious, and come in all shapes and sizes. As soon as Lucifer started melting the ice that covered theirt whole world, they began to emerge from the sea. Since then, they've developed at a speed that seems biologically impossible.'

'From what I remember about Europa, weren't there lots of cracks in the ice? Perhaps they'd already started crawling through and having a look round.'

'That's a widely accepted theory. But there's another, much more speculative, one. The Monolith may have been involved, in ways we don't yet understand. What triggered that line of thought was the discovery of TMA ZERO, right here on Earth, almost five hundred years after your time. I suppose you've been told about that?'

'Only vaguely – there's been so much to catch up with! I did think the name was ridiculous – since it wasn't a magnetic anomaly – and it was in Africa, not Tycho!'

'You're quite right, of course, but we're stuck with the name. And the more we learn about the Monoliths, the more the puzzle deepens. Especially as they're still the only real evidence for advanced technology beyond the Earth.'

'That's surprised me. I should have thought that by this lime we'd have picked up radio signals from somewhere. The astronomers started searching when I was a boy!'

'Well, there is one hint – and it's so terrifying that we don't like to talk about it. Have you heard of Nova Scorpio?'

'I don't believe so.'

'Stars go nova all the time, of course – and this wasn't a particularly impressive one. But before it blew up, N Scorp was known to have several planets.'

'Inhabited?'

'Absolutely no way of telling; radio searches had picked up nothing. And here's the nightmare...'

'Luckily, the automatic Nova Patrol caught the event at the very beginning. And it didn't start at the star. One of the planets detonated first, and then triggered its sun.'

'My Gah... sorry, go on.'

'You see the point. It's impossible for a planet to go nova – except in one way.'

'I once read a sick joke in a science-fiction novel – "supernovae are industrial accidents".'

'It wasn't a supernova – but that may be no joke. The most widely accepted theory is that someone else had been tapping vacuum energy – and had lost control.'

'Or it could have been a war.'

'Just as bad; we'll probably never know. But as our own civilization depends on the same energy source, you can understand why N Scorp sometimes gives us nightmares.'

'And we only had melting nuclear reactors to worry about!'

'Not any longer, thank Deus. But I really wanted to tell you more about TMA ZERO's discovery, because it marked a turning point in human history.'

'Finding TMA ONE on the Moon was a big enough shock, but five hundred years later there was a worse one. And it was much nearer home – in every sense of the word. Down there in Africa.'

8 – Return to Olduvai

The Leakeys, Dr Stephen Del Marco often told himself, would never have recognized this place, even though it's barely a dozen kilometres from where Louis and Mary, five centuries ago, dug up the bones of our first ancestors. Global warming, and the Little Ice Age (truncated by miracles of heroic technology) had transformed the landscape, and completely altered its biota. Oaks and pine trees were still fighting it out, to see which would survive the changes in climatic fortune.

And it was hard to believe that, by this year 2513, there was anything left in Olduvai undug by enthusiastic anthropologists. However, recent flash-floods – which were not supposed to happen any more – had resculpted this area, and cut away several metres of topsoil. Del Marco had taken advantage of the opportunity: and there, at the limit of the deep-scan, was something he could not quite believe.

It had taken more than a year of slow and careful excavation to reach that ghostly image, and to learn that the reality was stranger than anything he had dared to imagine. Robot digging machines had swiftly removed the first few metres, then the traditional slave-crews of graduate students had taken over. They had been helped – or hindered – by a team of four kongs, who Del Marco considered more trouble than they were worth. However, the students adored the genetically-enhanced gorillas, whom they treated like retarded but much-loved children. It was rumoured that the relationships were not always completely Platonic.

For the last few metres, however, everything was the work of human hands, usually wielding toothbrushes – soft-bristled at that. And now it was finished: Howard Carter, seeing the first glint of gold in Tutankhamen's tomb, had never uncovered such a treasure as this. From this moment onwards, Del Marco knew, human beliefs and philosophies would be irrevocably changed.

The Monolith appeared to be the exact twin of that discovered on the Moon five centuries earlier: even the excavation surrounding it was almost identical in size. And like TMA ONE, it was totally non-reflective, absorbing with equal indifference the fierce glare of the African Sun and the pale gleam of Lucifer.

As he led his colleagues – the directors of the world's half-dozen most famous museums, three eminent anthropologists, the heads of two media empires – down into the pit, Del Marco wondered if such a distinguished group of men and women had ever been so silent, for so long. But that was the effect that this ebon rectangle had on all visitors, as they realized the implications of the thousands of artefacts that surrounded it.

For here was an archaeologist's treasure-trove – crudely-fashioned flint tools, countless bones – some animal, some human – and almost all arranged in careful patterns. For centuries – no, millennia – these pitiful gifts had been brought here, by creatures with only the first glimmer of intelligence, as tribute to a marvel beyond their understanding.

And beyond ours, Del Marco had often thought. Yet of two things he was certain, though he doubted if proof would ever be possible.

This was where – in time and space – the human species had really begun.

And this Monolith was the very first of all its multitudinous gods.