'How are you doing?' he asked.

'My brain's in knots. Both brains, actually. I don't know where to start.'

'What's the problem?'

She told him what she had done so far. 'I'm not surprised you're stuck,' he said. 'You're doing a great job with the computer, but there's some biology you need to know. The brain can only think because of its structure. For the most part our neurons are pretty much identical – it's the way in which they're connected that allows them to think. It's like… Imagine a city.'

'London.'

'It's been shaken out of place and your job is to put the houses and streets back where they were. There are heaps of possibilities, but only one will give you London.'

'Fine, but how does each house know where it belongs?' Weaver sighed. 'No, scrap that question. Let's not worry about how the brain cells are connected. What I don't get is how they can join together and form something that's more intelligent than the sum of their parts.'

Anawak rubbed his chin thoughtfully. 'Think of the city again. In one of the streets a tower block is being built by a team of, say, a thousand workers. The workers are all identical – clones. Each has a specific task – a particular set of actions that he's employed to carry out. None of the workers has seen the blueprint for the building, yet together they're capable of constructing it. But imagine what would happen if you switched those guys around. There's a chain of ten builders passing bricks along the line, and you swap one for a man who tightens screws – well, you're going to cause trouble.'

'I see. So provided they stick to their jobs, the whole thing works fine.'

'Now, you could say that it only works because someone's been telling the workers what to do, but that someone couldn't build the block without them. Each presupposes the other. The plan gives rise to the workers' joint effort, and the workers' joint effort gives rise to the plan.'

'Is there someone who plans?'

'Maybe the workers are the plan.'

'Well, in that case all the workers would have to be coded slightly differently – which, come to think of it, they are.'

'Exactly. You see, the workers only seem to be identical. So, let's start at the beginning again. There's a plan. The units are all coded differently. What else do you need to make them into a network?'

Weaver thought. 'I guess they have to be willing to co-operate.'

'It's more straightforward than that.'

Suddenly she saw what he was getting at. 'Communication. A common language. A signal.'

'And what would the signal be telling the workers in the morning?

'Get up and go to the building-site.'

'Anything else?'

'Remember where you belong when you get there.'

'Exactly. But these guys are labourers, so they don't indulge in fancy conversation. They're hard-working men. They sweat in bed, they sweat when they get up in the morning- they're sweating all day long. How do they recognise each other?'

Weaver pulled a face. 'By their smell?'

'Bingo!'

'I'm beginning to worry about your imagination.'

Anawak laughed. 'It's Oliviera's fault. She was talking about those bacteria earlier, the ones that form aggregates, Myxococcus xanthus. Remember? They secrete a scent and group together.'

Weaver nodded. It made sense. I'll think it over while I'm swimming,' she said. 'Want to come?'

'Swimming? Now?'

'Yes, now,' she teased him. 'Listen, under normal circumstances I wouldn't spend the whole day cooped up in a room without moving.'

'I thought that was normal for computer geeks.'

'Are you saying I'm pale and flabby?'

'I've never seen anyone paler or flabbier.' He grinned.

She saw the sparkle in his eyes. He was small and compact, not exactly George Clooney, but right now he seemed tall, self-assured and good-looking. 'Idiot,' she said.

'Thanks.'

'Just because you spend half your life under water, you think anyone who works with computers must be chained to their desk. For your information, I do most of my work outdoors. I spend most of my time thinking. I grab my laptop and take off. There's no reason why you shouldn't write features from a cliff-top. Sitting here makes me tense up. I'm going to get shoulders like steel girders.'

Anawak stood up. For a moment Weaver thought he was leaving. Then she felt his hands on her back. His fingers stroked the muscles in her neck, while his thumbs kneaded her shoulders.

He was massaging her back.

Weaver stiffened.

She liked it. But did she want it?

'You're not tense,' said Anawak.

He was right. Why had she said it?

She stood up abruptly and his hands dropped away. She knew she'd made a mistake. She wanted to sit down again and let him carry on. But it was too late.

'Well, I guess I'll be going then,' she said awkwardly.

ANAWAK

He wondered what had gone wrong. He would have liked to join her in the pool, but the mood had changed. He should have asked before he massaged her shoulders. Maybe he'd misread the situation. You're no good at this kind of thing, he told himself Stick to your whales, you stupid Eskimo.

He thought about going in search of Johanson and continuing their discussion about single-cell intelligence, but somehow he didn't feel like it. He decided to stop by the CIC instead. Greywolf and Delaware spent much of their time there, monitoring and evaluating audio and video output from the fleet. But there was nothing to see except images of murky water from the cameras on the hull. Things had been quiet since the whales had circled the boat that morning, and now they seemed to have gone. Shankar was sitting on his own wearing a pair of oversized headphones, listening to the depths, while a constant stream of numbers passed before him on the screen. According to one of the crew, Greywolf and Delaware were busy on the well deck, substituting MK6 for MK7.

Anawak marched down the vehicle ramp and on to the empty hangar deck. It was cold and draughty. He'd been meaning to carry straight on, but something held him back. Although daylight was visible through the gate-like openings where the deck elevators were situated, the bay was dominated by the pale, yellowish glow of the sodium vapour lamps. He tried to imagine what it would look like when it was full of helicopters, Harrier jets, vehicles, cargo and equipment, all packed in with just enough room to open a door, climb through a window or slip into a hatch. Jeeps and forklift trucks would rattle up and down the ramps, and once the aircraft were on the roof, hundreds of marines would sort weaponry and equipment swiftly and intently. The formidable apparatus of the Independence would pull together as one.

The vast expanse of the bay seemed absurd in its emptiness. Useless. The booths between the ribs were unmanned. High among the steel girders on the gloomy ceiling, the yellow lamps had nothing to illuminate. Pipes ran along the walls, ending in the void. There were hazard signs everywhere, but no one to see them.

'If things get too cosy in the gym, we sometimes shift a few of the treadmills down here,' Peak had said, as he'd shown them round the vessel in Norfolk. 'Then it's real homey.' He'd stood there frowning. 'It's too empty. I hate to see the hangar like this. There are times when I hate this whole damn mission.'

The emptiest room, Anawak thought, is always on the inside.

He crossed the bay unhurriedly and walked out on to the portside elevator. The platform towered above the waves like a vast balcony. It was held in place by vertical slide rails that ran up the side of the ship. Anawak peered out across the water. The wind buffeted him. A strong gust could easily have swept him off his feet and over the edge of the platform. There weren't any rails, but safety nets encircled the ship so that no one could be pitched into the sea by the wind or aircraft exhaust.