'Was that wise?' asked Hvistendahl, in alarm. 'I thought we wanted to be as discreet as possible about, uh, putting our ear to the ground.'

'There was too much ground to cover. I had to set some boundaries.'

'Well, I hope you didn't say anything about-'

'I contacted them in my capacity as a biologist from the NTNU. A straightforward scientific enquiry.'

Skaugen pursed his lips. 'I don't suppose they were especially forthcoming.'

'That depends on how you look at it.' Johanson pointed to his file and the printouts. 'You have to read between the lines. Scientists make bad liars. They don't like politics. Their statements are like a dossier of muffled testimony – at times you can practically hear them shouting through their gags. I'm convinced that our worm has appeared elsewhere.'

'Convinced?' said Stone.

'So far no one's admitted it. But certain people became very curious.' Johanson looked at Stone. 'And they all happen to work for institutes with close ties to the energy industry. One of them is specifically involved in the technology of methane extraction.'

'Who?' Skaugen asked sharply.

'A scientist in Tokyo. Ryo Matsumoto. I didn't speak to him directly, only to his institute.'

'Who is he?' asked Hvistendahl.

'Japan's leading expert on gas hydrates,' said Skaugen. 'Worked on a methane-extraction project in Canada. He was testing drill sites in the permafrost.'

'His team got very excited as soon as I described the worm,' Johanson continued. 'They started asking questions. Was the worm capable of destabilising hydrates? How large were the colonies?'

'That doesn't mean they knew about it,' said Stone.

'Oh, yes, it does,' growled Skaugen. 'Matsumoto works for the Japan National Oil Corporation.'

'Are they interested in methane too?'

'You bet. In 2000 Matsumoto was mailing extraction methods in the Nankai Trough. The test results have been kept under wraps, but if he's to be believed, there are imminent plans for commercial extraction. The methane age is all he ever talks about.'

'Fine,' said Stone. 'But there's still no proof that he'd come across the worm himself.'

Johanson shook his head. 'Imagine our detective exercise in reverse. The enquiry comes to us. They ask my opinion as a so-called independent scientist. The person doing the asking is also a scientist and an adviser to the JNOC, but he claims he's writing out of scientific curiosity. Now, I don't want to tell him outright that we know about the worm. But I'm alarmed. I want to know what he knows. So I pump him for information, like Matsumoto's people did me. And that's the mistake. The questions I ask are too pointed, too targeted. If the scientist's got his wits about him, he'll know he's hit a nerve.'

'If that's true,' said Lund, 'then the Japanese continental slope has been affected as well.'

'But you don't have any proof' persisted Stone. 'There's not a shred of evidence to suggest that anyone other than us has come across it.' He leaned forward and the light caught the frame of his glasses. 'Dr Johanson, this type of information isn't any good to us. I'm sorry, but no one could have predicted the appearance of the worm because it's never been found elsewhere. I mean, for all we know, Matsumoto might just be curious to learn more about worms.'

'My instinct says he isn't,' said Johanson, unperturbed.

'Your instinct?'

'My instinct tells me that we haven't heard the end of it. The South Americans have found it too.'

'Let me guess. They asked leading questions too.'

'Exactly.'

'You disappoint me, Dr Johanson,' said Stone, scornfully. 'I thought you were a scientist. I assume you don't always rely on instinct.'

'Cliff,' said Lund, 'maybe you should shut up.'

Stone's eyes widened. He stared at her, outraged. 'I'm your boss,' he barked, 'and if anyone here needs to shut up it's-'

'That's enough,' said Skaugen. 'Not another word.'

Johanson could see that Lund was having difficulty containing herself He wondered how Stone had provoked her. 'In any case', he went on, 'I think Japan and South America know more than they'll let on. Just like us. Fortunately it's much easier to get reliable data on water than it is on deep-sea worms. There's hardly a stretch of water that isn't under analysis at any one time. I tapped a few people for information, and they confirmed the situation.'

'Which is?'

'Unusually high quantities of methane are entering the water column. It all fits.' Johanson hesitated. 'I'm sorry to bring instinct into this again, Dr Stone, but when I was speaking to Matsumoto's people I had the impression that they were trying to let me guess the truth. No doubt they were sworn to secrecy, but no serious scientist or institute would play with information that people's lives depend on. It's indefensible. It only happens when-'

Skaugen frowned at him. 'When economic interests are at stake,' he said. 'Is that what you're saying?'

'Yes. Indeed.'

'Is there anything you'd like to add?'

Johanson pulled a printout from the pile. 'High levels of methane are being recorded in three areas of the world: Norway, Japan and off the east coast of Latin America. Then there's Lukas Bauer's data.'

'Who's he?' asked Skaugen.

'He works on deep-water currents. He's in the Greenland Sea right now. He uses drifting profilers to track the currents, then maps the data. I emailed his vessel. Here's what he had to say.' Johanson started to read: "Dear Colleague, I'm afraid I'm not acquainted with your worm, though we are recording exceptionally high levels of methane in the Greenland Sea. In fact, in certain areas, large quantities of gas are seeping into the water. It may have something to do with the discontinuities we're observing here – a nasty business, if I'm right. I'm sorry this is rather sketchy, but I'm awfully busy right now. I'm attaching a detailed report by Karen Weaver, a journalist who's here to help me and distract me with her questions. She's a smart girl, and she'll deal with any further queries. You can contact her on [email protected].'

'What kind of discontinuities does he mean?' asked Lund.

'No idea. When I met him in Oslo, he seemed a little absent-minded – likeable, but the epitome of a scientist. He forgot to attach the report, so no surprises there. I emailed straight back, but he hasn't replied.'

'We should probably find out exactly what he's working on,' said Lund. 'Bohrmann'll know, won't he?'

'I'm guessing the journalist does too,' said Johanson.

'Karen… ?'

'Karen Weaver. I thought the name was familiar. Turns out I'd read some of her articles. Interesting woman. Studied biology, computer science and sport. She focuses on marine-related issues – always the big themes: charting the seas, plate tectonics, climate change. Her latest article was on deep-water currents. As for Bohrmann, I'll give him a call if he hasn't contacted me by the end of the week.'

'So, where does that leave us?' Hvistendahl asked them.

Skaugen's blue eyes settled on Johanson. 'Dr Johanson has told you what he thinks. It would be a disgrace for the oil industry to withhold information when people's lives may depend on it. Unquestionably he's right. That's why yesterday afternoon I had a meeting with the board, and made some clear recommendations – as a result of which the Norwegian government has now been informed.'

Stone's head jerked up. 'Informed of what – We don't have any firm results. We don't even-'

'Informed about the worms, Clifford. And about the dissociation of the methane deposits. About the risk of an impending methane disaster. And the danger that the slope could collapse. We even told them that our deep-sea robot filmed an unknown organism in the ocean. Isn't that enough?' Skaugen frowned at them all in turn. 'Dr Johanson will be pleased to know that his instincts were right. This morning I had the pleasure of an hour-long conversation with the scientific board of the JNOC. Now, I'm sure you all realise that it's a reputable company, but suppose for a moment that the Japanese were so eager to lead the way in methane extraction that they were prepared to do anything to succeed before the rest. Unlikely as it sounds, it could result in a certain amount of risk-taking – or maybe in a tendency to overlook expert opinion.' Skaugen's gaze shifted to Stone. 'Then imagine that there are people in this world whose ambition might tempt them to disregard warnings and suppress vital evidence. Oh, I know it's absurd but, hypothetically, if it were true… Well, think how dreadful it would be. We'd have to suspect the JNOC of masterminding a cover-up to hide the existence of a worm that had threatened the nation's dream of being first to get to the methane. We'd have to suspect that they'd been doing it for weeks.'