He stood, paralysed, in front of the screens. There's no reason to be shocked, he told himself. The worms live symbiotically with bacteria that break down hydrates, but they're equipped with jaws for burrowing.

The solution was obvious. The worms were trying to reach the bacteria buried deeper in the ice. He watched them, fascinated, as they dug into the hydrates, their rear ends wiggling. Then they were gone. Only the holes remained, two dark patches in the ice.

It's nothing to get worked up about, he thought. Some worm species spend their whole lives burrowing. But why would they burrow into hydrates? 'Where are they now?' he asked.

Sahling glanced at the monitor. 'They're dead.'

'Dead?' Johanson echoed.

'They suffocated. Worms need oxygen.'

'I know – that's the whole point of the symbiosis. The bacteria produce nutrients for the worm, and the worm provides oxygen for the bacteria. What went wrong?'

'They dug themselves to death. They chomped their way through the ice, fell into the pocket of methane and died.'

'Kamikaze worms,' muttered Johanson.

'It does look like suicide.'

Johanson thought for a moment. 'Unless they were thrown off-course by something.'

'Maybe. But what^? There's nothing in the hydrates that could explain such behaviour.'

'Maybe the gas pocket.'

Bohrmann scratched his chin. 'We wondered about that, but it doesn't explain why they'd dig their way to death.'

Johanson pictured the mass of wriggling worms at the bottom of the ocean. He was feeling increasingly uneasy. What would happen if millions of worms burrowed into the ice?

Bohrmann seemed to hear his thoughts. 'The worms can't destabilise the ice,' he said. 'On the seabed the hydrate layers are infinitely thicker than they are here. Even crazy creatures like these would only dent the surface. They'd manage a tenth at most before death reeled them in.'

'So, what's the next step? Will you test some more specimens?'

'We can use the worms we kept in reserve. Ideally, though, we'd like to examine them in situ. That should please Statoil. In a few weeks' time the RV Sonne will be leaving for Greenland. If we set sail a little earlier, we could stop off at the place where they first showed up and take a look.' Bohrmann shrugged 'It's not up to me, though. We'll have to wait for a decision. It was just an idea I developed with Heiko.'

Johanson glanced back at the tank and thought of the dead worms. 'It's an excellent idea,' he said.

AFTER A WHILE JOHANSON went back to the hotel to get changed. He tried to reach Lund, but she wasn't picking up. He imagined her lying in Sverdrup's arms and hung up.

Bohrmann had invited him to dinner that evening in one of Kiel's best restaurants. He went into the bathroom and inspected himself in the mirror. His beard needed trimming, he thought. It was at least two millimetres too long. Everything else was just right, though. His once-brown hair was thick and shiny, despite the strands of grey, and his eyes still twinkled beneath heavy brows. At times he found it hard to resist his own charisma. One of his female students had told him that he looked like the actor Maximilian Schell. Johanson had felt flattered – until he found out Schell was over seventy.

He rummaged through his suitcase, pulled out a zip-neck sweater and put it on, then struggled to force his suit jacket over the top. He wrapped a scarf round his neck. He didn't look well dressed, but that was how he liked it. He cultivated a scruffy look. It took him longer to achieve his dishevelled hairstyle than most people would spend on a respectable coiffure.

He flashed himself a smile in the mirror, left the hotel, and took a taxi to the restaurant.

Bohrmann was waiting for him. They had a few glasses of wine with their dinner, but eventually the conversation drifted back to the ocean. Over desert Bohrmann asked casually, 'How much do you know about Statoil's plans?'

'Only the basic details,' said Johanson. 'I'm not especially well informed about oil.'

'What are they planning? It can't be a platform – it's too far out to sea.'

'It's not a platform.'

'I don't want to pressure you and I've no idea how confidential these things are…'

'I shouldn't worry about that. I've been told, it can't be very secret.'

Bohrmann laughed. 'So, what are they building out there?'

'They've got plans for a subsea plant. A fully automated one.'

'Like SUBSIS?'

'What's that?'

'Subsea Separation and Injection System – a unit off the coast of Norway in the Troll field. It's been active for a number of years now.'

'Never heard of it.'

'You should ask the guys who sent you here. SUBSIS is a processing plant that operates three hundred and fifty metres down. It separates the water from the oil and gas at seabed level. In conventional plants, the process takes place on the platforms and the water is discharged into the sea.'

'Oh, I remember!' Lund had said something about it. 'The water makes fish infertile.'

'SUBSIS can get round that. The water is injected back into the reservoir, pushing the oil upwards, so more oil pumps out. In the meantime, the water is removed, re-injected, and so it goes on. The oil and gas are carried through pipelines to the coast. It's pretty neat, as far as it goes.'

'But?'

'I'm not sure there is a but. SUBSIS is supposed to work perfectly in depths of up to fifteen hundred metres. Its manufacturer thinks it can do two thousand, and the oil companies are aiming for five thousand.'

'Is that feasible?'

'In the not too distant future, yes. Anything that works on a small scale will probably work on a larger one, and the advantages are obvious. It won't be long before remote-controlled plants replace all of the platforms.'

'You don't sound enthusiastic,' said Johanson.

There was a pause. Bohrmann seemed unsure how to respond. 'What bothers me isn't the subsea plant as such. It's the naivety of it all.'

'It's a remote-controlled unit?'

'Fully automated. It's operated from the shore.'

'Which means repairs and maintenance work are carried out by robots.'

Bohrmann nodded.

'I see,' said Johanson.

'There are pros and cons,' said Bohrmann. 'It's always risky when you enter unknown territory. And, let's face it, the slopes are certainly that so it makes sense to automate the system. There's nothing wrong with sending down a robot to do a bit of monitoring or to take a few samples. But a subsea station is a different proposition. Suppose oil spurts out of a well five thousand metres down. How are you going to fix it? You don't know the terrain. All you've got is piles of data. We're as good as blind down there. OK, we can use satellites, digital sonar and seismic profiling to create a map of seabed morphology that's accurate to within half a metre. OK, we've got bottom-simulating reflectors to detect oil and gas deposits, so we can tell where we should drill, where we'll find oil, where the hydrates are stored, and where best to avoid… But as for what's down there, no one really knows.'

'That's my refrain,' murmured Johanson.

'Don't get me wrong, I'm not against fossil fuels per se, but I object to making the same mistake twice. When the oil industry took off, we erected our junk in the sea, without anyone thinking about how we could dispose of it. We emptied wastewater and chemicals into rivers and seas, as though they'd simply disperse. Radioactive material was dumped in the oceans. Natural resources and life-forms were exploited and destroyed. No one stopped to consider how complex the connections might be.'

'But subsea plants are here to stay?'

'Almost certainly. They're more economic, and they can tap oil reserves that humans can't reach. After that, the stampede will start for methane. It burns more cleanly than fossil fuels and it will slow down the greenhouse effect. All the arguments in favour are perfectly valid – providing everything goes to plan. People in these companies often confuse what should happen in an ideal scenario with what could happen in reality. It makes their lives easier. Whenever they're presented with a range of possible outcomes, they pick the most favourable so they can start work straight away – even if they know nothing about the world they're intruding on.'