Peak looked at Buchanan. 'She's right, Craig,' he said. 'You should admit it. They're both right.'

'We're not a successful species,' said Crowe. 'If you want to see a successful species, you should take a look at the shark. It's survived in unchanged form since the Devonian, four hundred million years ago.

Sharks are a hundred times older than any member of our genus, and there are three hundred and fifty different species. The yrr could be even older than that. Single-cell organisms that can think collectively would be light-years ahead of us. We'd never catch up. The only thing we could do is destroy them. But would you really want to take that risk? We don't even know what role they play in our survival. Maybe we'd find it even harder to live without this particular enemy than we do to live with it.'

YOU WANT TO protect American values?' Johanson shook his head. 'In that case, we're bound to fail.'

'What have you got against American values?'

'Nothing. But you heard what Crowe said: intelligent life-forms from other planets probably have nothing in common with humans or mammals. They may not even have DNA. Their system of values is likely to be completely different from ours. What kind of social and moral framework do you think you're going to find in the depths? We're talking about a species whose civilisation probably depends on cell division and self-sacrifice. How are you going to reach any kind of agreement with them, if all you're concerned about is the preservation of values that even humans can't agree on?'

'That's not what I meant,' said Li. 'I know we don't have the monopoly on ethics. But the question is this: is it absolutely necessary to understand how others think? Or wouldn't it be better to invest all our energies in trying to coexist?'

'Living in peace alongside each other?'

'Yes.'

'If only we'd thought of that before,' said Johanson. 'I think the native peoples of America, Australia, Africa and the Arctic would have welcomed that idea. Same goes for all the animal species that we hunted to extinction. But the situation's not that straightforward. I don't suppose for a second that we'll ever really understand how they think, but we've caused each other too much trouble not to try. Our habitat's too small for us to keep living side by side. We need to learn to live together. And there's no way we'll be able to do that unless we scale back our expectations concerning humanity's so-called God-given rights.'

'How do you propose we do that, then? By adopting the customs of amoebas?'

'Of course not. It's genetically impossible, anyway. What we refer to as customs or culture is inscribed in our genes. Cultural evolution began in prehistoric times. That was when our mind was laid out. Sure, these days we design aeroplanes, helicopter carriers and opera houses, but only to continue our primitive activities on a so-called civilised plane. It's what we've been doing since the first axe was bartered for a slab of meat: going to war, congregating in social units, trading. Culture is part of our evolution. It allows us to survive in a stable condition-'

'Until another species with greater stability turns out to be superior. I see what you're getting at, Sigur. It's not something we like to dwell on, but genes are what's allowing us to have this conversation in the first place. We're so proud of our intellectual heritage, but it's just the result of biology. Culture is nothing but a set of successful patterns of behaviour grounded in our struggle to survive.'

Johanson didn't respond.

'Did I get something wrong?' said Li.

'No, I was listening in silent admiration. You're absolutely right. Human evolution is just the interplay between genetic mutation and cultural change. We owe the growth of our brains to genetic mutations. It was biology that allowed us to speak. Five hundred thousand years ago, nature restructured our vocal apparatus and built the language centres in our cortex. And these genetic mutations fired our cultural evolution. Speech gave us the ability to express our thoughts, describe our past, discuss our future, and give voice to our imagination. Culture is the product of biological processes, and biological adaptation occurs in response to cultural change. The whole process takes generations, of course, but it happens all the same.'

Li smiled. 'I'm glad I passed the test.'

'I never suspected otherwise,' Johanson said graciously. 'But you've pinpointed the problem: our much-vaunted cultural diversity is bounded by genetic limitations. And those limitations clearly separate our culture from the culture of non-human intelligent beings. Over time, mankind has created numerous cultures, and each is based on the imperative of keeping our species alive. We could never adopt the values of a species whose biology isn't compatible with our own. They're our rivals in the struggle for habitat and resources.'

'So you don't believe in the Federation, with walking electronic beehives queuing up beside us at the bar?'

'Star Wars? 'Yes.'

'A great movie. No. That would only work if we could somehow suppress our instincts over hundreds of thousands of years. We'd need our genes to be reprogrammed towards inter-species co-operation.'

'Which proves that I'm right. We shouldn't try to understand the yrr. We should find a way of leaving each other in peace.'

'That's the snag. They won't leave us in peace.'

'Then we've lost.'

'Why?'

'Didn't you just say that humans and non-humans will never reach a consensus?'

'The same could be said for Christians and Muslims. Listen, Jude, understanding the yrr isn't an option. We'll never be able to understand them. But we have to make room for what we can't understand. That's not the same as allowing their values to hold sway – or vice versa. The solution lies in retreat. And, right now, it's our retreat that's being called for. It can work, you know. It doesn't mean we have to understand them emotionally – that would be impossible. It just means looking at things from a different, broader perspective, and we can do that by taking a step back from ourselves as a species. Because without that distance, we'll never be in a position to present the yrr with a view of us that's any different from the one they've got now.'

'But we're retreating already. We're trying to make contact – isn't that enough?'

'And what are you hoping to gain from making contact?'

Li said nothing.

'Jude, tell me something. How is it that I hold you in such high esteem yet with so little trust?'

The noise of the debate drifted over from the other tables. It gathered like a wave sweeping over the deck, breaking as it hit them. The scraps of conversation became raised voices, then shouting. At that moment an announcement came through the speakers: 'Dolphin alert! Warning! Dolphin alert!

Li was the first to wrench her eyes from the duel. She turned her head and looked towards the dusky sea.

'Oh, God,' she whispered.

It had started to glow.

BLUE CLOUD

All around them the waves were tinged with luminous blue. Shimmering violet pools surfaced on the water, spreading and merging, as though the sky were pouring into the ocean.

The Independence was suspended in light.

'Whatever you said in that message, you certainly made an impression,' said Greywolf to Crowe, as he stared at it.

'It's so beautiful' Delaware said softly.

'Look!' cried Rubin.

The veil of light began to stir. The glow pulsated. Enormous whirlpools formed, turning slowly at first, then ever faster, until they were rotating like spiral galaxies, drawing in fresh streams of blue. The light at the centre of the whirlpools intensified. Thousands of tiny stars lit up, then faded.