'Yes, but are we intelligent and conscious?'

Rubin blinked in confusion. 'How do you mean?'

'Are we aware of our intelligence?'

'Well, obviously.'

'Or maybe we're computers with an inbuilt learning capacity? Of course we know the truth, but do they? Theoretically it would be possible to replace the entire brain with an electronic equivalent, and then you'd get AI. Your artificial brain would be capable of doing everything that you can do. It could build you a spaceship and outsmart Einstein. But would it be aware of its achievements? In 1997 the world chess champion Garry Kasparov was defeated by an IBM computer, Deep Blue. Does that mean Deep Blue was conscious? Or did it win without seeing the point? Does the fact that we build cities and lay underwater cables prove that we're intelligent, conscious beings? SETI has never excluded the possibility that one day we might come across a machine civilisation; computer intelligence that has outlived its creators and continued to develop over millennia by itself.

'And the creatures down there? If what you're saying is true, maybe the yrr are just ants with fins. A species without any ethics, without even any-'

'Exactly. And that's why we're proceeding in stages.' Crowe smiled. 'Stage one, I want to find out if there's anything down there; stage two, I want to establish whether dialogue is possible; and stage three, I want to know if the yrr are consciously responding to our messages – if their intelligence is conscious at all. Only then – once we've reason to believe that in addition to their evident knowledge and skill they're able to conceptualise and understand – will I be prepared to consider them as intelligent beings. And only then would it be worthwhile reflecting on their values – but even then we shouldn't expect those values to bear the slightest resemblance to our own.'

For a while there was silence.

'I don't want to interfere in a scientific debate,' Li said finally, 'but pure intelligence is unfeeling. Intelligence connected to consciousness is an entirely different matter. In my opinion, an intelligent conscious being would necessarily have values. If the yrr represent conscious intelligence, they'd have to recognise at least one value: the value of life. And since they're trying to defend themselves, that would seem to be the case. I'd say they've got values. What we need to find out is whether those values coincide in any way with our own. Maybe there's the tiniest overlap.'

Crowe nodded. 'Yes,' she said. 'Maybe there is.

LATE THAT AFTERNOON they bundled the first sound wave and sent it into the depths. Shankar had chosen a frequency to match the spectrum of the unidentified noises that his SOSUS colleagues had christened Scratch.

The modem set about modulating the signal. The sound wave was subject to a certain amount of reflection, so Crowe and Shankar sat in the CIC, modulating the modulations until the distortion was gone. An hour after the signal had been broadcast, Crowe felt confident that any creature capable of detecting acoustic signals would have no trouble receiving it. Whether the yrr would make sense of it remained to be seen.

They might not bother to reply.

Perched on the edge of her chair in the half-light of the CIC, Crowe felt a wave of elation at the thought of how close they were to the moment she'd always longed for: contact. But, more than anything, she was afraid. She could feel the burden of responsibility weighing on her and the rest of the team. This wasn't an adventure like Arecibo and Project Phoenix: it was up to them to avert a catastrophe and save mankind from destruction. 'The SETI researcher's dream had turned into a nightmare.

FRIENDS

Anawak made his way up through the vessel, then strode along the narrow passageways in the island and emerged on the flight deck. Over the course of the voyage, the roof had turned into a kind of promenade. Anyone with a few moments to spare could be found strolling along it, deep in thought or deliberating in groups. In an unlikely twist of fate, the roof of the largest helicopter-carrier in the world, usually the site of innumerable take-offs and landings, had developed into a place of contemplation and scientific debate. The six Super Stallions and two Super Cobras waited forlornly on the vast expanse of tarmac.

On board the Independence, Greywolf continued to lead his exotic life, although Delaware was ever more a part of it. The two were growing steadily closer. Delaware wisely gave him space, which meant that Greywolf sought out her company. In public, they never let slip that they were more than friends, but Anawak could see that their bond was growing. The signs were unmistakable. Delaware rarely worked with him now: she spent all her time looking after the dolphins with Greywolf.

Anawak found Greywolf sitting cross-legged at the bow, looking out across the ocean. As he started to sit down, he realised Greywolf was carving.

'What is it?' he asked.

Greywolf passed it to him. It was a large object, skillfully carved from cedarwood. It looked almost finished. One end finished in a handle, while the larger section showed a number of intertwined figures. Anawak could make out a bird, two animals with powerful jaws, then a man, who seemed to be at their mercy. He ran his fingers along the surface. 'It's beautiful,' he said.

'It's a copy.' Greywolf grinned. 'I only ever make replicas. I don't have it in me to come up with an original.'

'I get it.' Anawak smiled. 'You're not Indian enough.'

'You don't get anything – you never do.'

'OK, calm down. So, what is it?'

'It's a ceremonial hand-club. From the Tla-o-qui-aht. The original was made of whalebone, in a private collection from the late nineteenth century. The figures tell a story from the time of the ancestors. One day a man came across a mysterious cage with all kinds of creatures inside it. He took it back to his village. Soon afterwards he fell ill and no one could cure him. There didn't seem to be any explanation for his illness, but then the answer came to the sick man in a dream. 'The creatures in the cage were to blame. They weren't just animals, they were transformers, shapeshifters, and they attacked him in his sleep.' Greywolf pointed to a squat creature. 'This one's a wolf-whale. In the dream it attacked the man and closed its jaws round his head. Then Thunderbird tried to save him. You can see how it's digging its claws into the wolf-whale's flank. While they were fighting, a bear-whale joined them and grabbed the man by his feet. The man woke, told his son the dream and died. The son carved this club and used it to kill six thousand shapeshifters to avenge his father's death.'

'And what's the hidden meaning?'

'Does everything have a hidden meaning?'

'A story like that is bound to have a hidden meaning. It's the eternal struggle, isn't it? The battle between good and evil.'

'No.' Greywolf pushed the hair out of his eyes. 'The story tells of life and death. In the end you die, but until then your life is in flux. You can live a good life or a bad life, but you don't control what happens to you – that's for higher powers to decide. If you live in harmony with Nature, she will heal you; if you fight her, she will destroy you. But the important point is that you don't control Nature – she controls you.'

'The man's son doesn't seem to have shared that insight,' said Anawak. 'Otherwise why would he have sought vengeance for his father?'

'The story doesn't say he was right.'

Anawak handed the club to Greywolf, reached into his anorak and pulled out the bird spirit. 'Can you tell me anything about this?'

Greywolf turned it in his hands. 'It doesn't come from the west coast,' he said.