The only person not sitting down was Purna. She glanced at Logan and then at Xian Mei.

'Are you two OK to carry on?'

In any other situation Logan would have laughed and told her to take a hike, but now he simply nodded and with Sam's help rose to his feet.

'It's OK,' Sam mumbled. 'There ain't no more zombies.'

'Good,' said Logan, 'because I think I lost my gun. I hope Purna doesn't make me pay for it.'

Led by Kevin, the seven of them made their way slowly along the long corridor to a door at the far end. This one was open like the others (Thank you, Ryder White, Logan thought) and led through a number of empty administrative offices and linking corridors to a central lobby area where several corridors converged. There was no sign of the infected in this part of the building, and indeed no sign they had ever been here. The left-hand wall was dominated by a lift with metal doors.

'This is it,' said Kevin. 'Sector Seven awaits.'

He pressed the button and the downward-facing arrow lit up. For a few seconds they waited, not speaking, like strangers in a hotel lobby. There was a ping and the lift doors slowly opened. They shuffled inside and Kevin pressed a button marked 7. As soon as the lift doors closed, Logan heard a hissing sound, which at first he thought was something to do with the lift mechanism. Then Purna said, 'What's that?'

'That's the gas,' said Kevin, his voice oddly muffled.

Logan turned, bemused, and saw that Kevin had released a small catch next to the lift buttons, which had caused a flap to drop down. Behind the flap was a compartment, like a tiny locker, from which Kevin, shielded by the people standing next to him, had produced a gas mask. He was now wearing the mask and the hissing was getting louder.

'What-' Purna said, then her legs folded under her and she slid unconscious to the floor.

Gas? Logan thought, trying to make sense of what was happening, but all at once his mind felt slow and syrupy, his head heavy as a boulder. The last thing he saw, before his body shut down and he blacked out for the second time in an hour, was Kevin's masked face goggling down at him.

Chapter 23.

SECRETS AND LIES.

'SO THIS IS what it's all about. It really doesn't look like much, does it?'

The words tugged Sam up from a black pool of unconsciousness. He opened first one eye and then the other, his head pounding as if he was suffering from the worst ever hangover. He was vaguely aware he was sitting in a chair, but had no idea how he had got there. The last thing he remembered was ...

The lift! The memory snapped him fully awake and he tried to jump to his feet.

But he couldn't move. He was paralysed. Kevin's gas had paralysed him! Then he realized his back was aching, and there was a glassy cramped feeling in his shoulders, and something was cutting into his wrists.

Not paralysed then. Thank God. Not paralysed, but immobile all the same. Tied to a chair.

He blinked to clear his blurred vision, turned his head towards the source of the words he had heard echoing in his mind. He saw a smear of orange (Hallowe'en pumpkin orange, he thought, and felt a sudden pang of nostalgia for his childhood). Then the smear tightened, coalesced, and he realized he was looking at Kevin in his orange prison overalls.

The skinny man was leaning against a control desk, backlit by the icy glare from a wall of TV screens. The screens depicted different static views of the prison corridors and cell areas, kitchens, shower blocks, the library, the exercise yard. Sam could see that most of the places were deserted, but in a few the infected milled about like sleepwalkers. He turned his attention back to Kevin. The man was holding up a vial of yellowish liquid that resembled weak tea or piss.

'What's going on?' Sam mumbled and Kevin glanced across at him.

'Oh, welcome back,' he said. 'Enjoy your little nap?'

Sam ignored him, looking around to take in his surroundings. He was relieved to see his friends were all here, and apparently OK aside from the fact that, like him, they had been manacled to chairs and had had their backpacks and weapons taken away.

Of the others, Purna and Xian Mei were the only ones who were conscious. Logan, Jin and Yerema were still slumped forward, eyes closed, breathing heavily.

Xian Mei looked ill, her skin clammy, her face and body tense as if the slightest movement caused her pain. The thick bandage around her arm was stained red where blood had seeped through from the wound beneath.

'You OK?' Sam asked her.

She licked her lips and gave a tiny unconvincing nod.

In contrast to Xian Mei, Purna looked fighting fit, her dark eyes blazing with anger.

'What do you hope to gain from this, Kevin?' she said, making his name sound like an insult.

'Oh, I've already gained it,' he said.

She scowled. 'What are you talking about?'

Smiling and slipping the vial into his pocket, he said, 'Let me tell you a little story.'

'Oh, is this the bit where the bad guy gloats about how clever he's been and the good guys get bored?' Sam said.

Kevin looked for a moment as if he was contemplating whether to punch Sam in the face, and then he snorted a laugh and settled himself more comfortably against the desk, folding his arms.

'Not exactly,' he said. 'It's more the bit where the little unimportant people discover how the world really works, and how they can do absolutely nothing about it.'

'That sounds even more boring,' Sam muttered.

'So tell us,' said Purna with weary contempt, 'how does the world work? In your estimation?'

Kevin smirked. 'Why do you think you're really here on Banoi?'

'Because we're immune,' said Purna. 'Because we were brought here to be manipulated, to be used as guinea pigs.'

Kevin nodded. 'And why are you here now? In the prison, I mean?'

''Cos this guy, Ryder White, said he'd get us off the island if we brought him the vaccine,' said Sam.

Clearly amused, Kevin raised a hand and waggled it from side to side. 'Well ... that's partly right,' he said. 'But I'm afraid that's not the full story.'

'All right,' Purna conceded, 'so why don't you tell us the full story? I can see you're dying for the opportunity to let us know how clever you've been. Why don't you start by telling us who you really are, because you sure as hell aren't a regular prisoner?'

Kevin pursed his lips, as though inwardly debating how much to reveal. Eventually he said, 'My name is Charon. I'm a sleeper agent for the Organization-'

'The Organization?' Purna interrupted mockingly. 'Ooh, how mysterious.'

The man now called Charon shrugged, unmoved by the taunt. 'It doesn't have a name because it doesn't officially exist. It's a secret association of the world's wealthiest individuals, who make their money by exploiting certain financial opportunities that arise in areas of global conflict.'

'So they're like vultures?' asked Sam. 'Feeding on the misery and destruction of innocent people?'

Charon sneered. 'I wouldn't expect you to understand.'

'Oh, we understand more than you think,' Purna's voice dripped contempt. 'I know how people like that operate, and they're not opportunists. They might have been once, but when your financial profile achieves a certain level, you no longer passively sit around, waiting for something to happen. You make things happen. You stoke the fires. And if misery and chaos is big business, then you make damn sure you're the one creating it.'

'So they start wars?' asked Sam. 'And they created this virus to use as a weapon they can sell to the highest bidder?'

'Of course they did.' Purna shot Charon a contemptuous look. 'Isn't that right?'

Charon inclined his head. 'Partly. But the Organization didn't create the virus. The virus was already here, on Banoi. The Organization invests a huge amount of money in research and development. They probe every branch of science looking for potential new weapons, and they have eyes and ears everywhere.'

'And they heard about the virus?' said Sam.

Kevin nodded. 'The first of the infected to come back from the dead were taken off the island and tested.'

'Yerema's rapists,' said Purna, glancing at the girl.

'Precisely,' replied Kevin. 'And tests showed that in all three of them the virus Pathogen K could not be isolated because it was constantly mutating. And so in order to create a usable biological weapon, a stable form of Pathogen K had to be found so that a vaccine could be developed.'

'Because without a vaccine the virus would be useless as a biological weapon,' said Purna.

'Which is where you guys came in,' said Charon, spreading his hands expansively. 'It was discovered that, despite the aggressive nature and constantly mutating state of the virus, a tiny percentage of people were completely immune. The Organization therefore used its resources to scan blood records the world over. They even created a multi-national blood drive event under a variety of banners and initiatives to cast their net still further. Ultimately you four were selected from millions of potential subjects. It was discovered that you possessed the most vigorously resistant immune systems, strong enough to withstand close proximity engagement with the infection. Plus you fitted the required demographic survival profile.'

'You mean we were young and fit and we wouldn't get sick,' said Sam.

'Precisely.'

'So you dropped us into the middle of all this shit just so we'd get the original stable form of the virus for you?'

'Dropping a trail of crumbs for you to follow along the way, yes,' replied Charon smugly.

'I assume West was in on this?' asked Purna.

Charon smirked. 'Mowen too. Such a shame about poor Dr West, though he served his purpose. I'm sure the vaccine he developed, combined with his notes which you were thoughtful enough to bring along with you will prove invaluable.'

'So all that shit about Ryder White's wife-' said Sam.

'Oh, that's all true,' said Charon, still smirking. 'It's always more convincing if you conceal a few droplets of truth in an ocean of subterfuge.'

Sam frowned. 'So this Ryder White guy works for the Organization too?'

'No.'

Sam stared at Charon for a long moment and then shook his head. 'I don't get it.'

'I think I do,' said Purna. Narrowing her eyes, she said, 'It wasn't Ryder White who contacted us, was it? It was you.'

'Guilty as charged,' said Charon, holding up his hands.

'So Ryder White don't know squat about us?' asked Sam.

'Oh, he knows there are operatives on Banoi, trying to locate a stable form of the virus in order to develop a vaccine that he hopes will save his wife. If he hadn't been furnished with that information, the island would have been destroyed and all our hard work would have been for nothing.'

'All your hard work?' yelled Sam. 'You make it sound like this fucking virus is some kind of achievement.'

'And so it is,' said Charon. 'The ultimate biological weapon, for which potential buyers will be willing to pay untold sums of money?' He laughed. 'What's not to like?'

Sam looked as if he was about to explode, but before he could say anything, Purna glanced at him quickly. 'Hang on, Sam.' Turning back to Charon, she said, 'What do you mean, if White hadn't known we were looking for a vaccine, the island would have been destroyed? Destroyed by who?'

Charon sighed, as if her lack of understanding was becoming tiresome. 'After analysing the virus, scientists working for the Organization were able to predict that once the plague was introduced into the general population, it would spread quickly. Exactly how quickly they weren't sure and in the event it achieved pandemic proportions far more rapidly than anyone had anticipated but they at least knew that the potential was there, and so were able to instigate various precautionary measures.'

'Such as?'

'It's not a widely known fact, for obvious reasons, but for some time now western governments have been running scared of the possibility of terrorist groups developing biological and chemical weapons so devastating that, if unleashed, they would decimate the populations of entire countries. In order to counter act this, certain measures have been agreed upon, measures that would be met with widespread horror and condemnation if their existence were made public. Suffice to say that a pandemic with no fore seeable cure such as the one currently rampant on Banoi would ordinarily trigger the execution of security protocols, resulting in the nuclear cleansing of the infected area.'

'Nuclear cleansing?' sneered Sam. 'You mean they'd blow the fucking place sky high? Murder thousands of innocent people?'

'In order to protect the majority, yes,' said Charon. 'But I'm only the messenger boy, not the instigator here so let's not get bogged down quibbling about the moral issues.'

'You said "ordinarily",' said Purna, 'which I'm guessing means that because of these "precautionary measures" you mentioned, what was supposed to happen hasn't happened in this case?'

Charon nodded.

Purna looked as though she was about to ask him another question, then her eyes widened. 'Oh my God.'

'What?' asked Sam.

Looking intently at Charon, Purna said, 'Let me take a wild guess: Ryder White would be the man in charge of ordering the nuclear strike on Banoi, right?'

Charon's smile was confirmation enough.

'Don't you see?' said Purna to a stillbemused Sam. 'The reason Banoi hasn't been wiped off the face of the earth is because Ryder White's wife is sick, and he's delayed the order because he thinks the cure might be on the island. But the question is, why did she get sick in the first place?'

Sam felt like the kid in class who doesn't get what everyone else seems able to grasp and then all at once he did get it. 'Because they made her sick,' he said, nodding at Charon.

'Exactly.'

Sam shook his head in disbelief. 'Bastards.'

'Oh, please,' said Charon wearily, 'less of the bleeding heart bullshit. It was purely a practical decision. The Organization simply needed a way to buy some time. It was discovered that Ryder White's wife was the physician here, so the infection was planted in the prison. As the doctor treating the sick prisoners it was inevitable she would contract the virus sooner rather than later and hence the nuclear threat, luckily for you, was allayed.'

'So where are White and his wife now?' asked Purna.