And then they were sitting on the hard, uncomfortable floor with Suliman and his men looking on at them with pure hatred. Suliman particularly refused to take his dead eyes off Ben, who could only imagine what was going through his head. Only the threatening presence of three peacekeeping guards and their weapons stopped the situation erupting into violence – of that, Ben was sure. The guys from the UN might look scary, he thought to himself, but he was glad they were there.

Clearly Sam Garner must have heard his message.

'Where are we going?' he shouted at the guard who was nearest them as he felt the Chinook rise up into the air.

'Back to the village you came from, sir,' came the reply in a Midwestern American accent.

'Then what?'

There was a pause. 'Quarantine.'

Ben nodded grimly. Deep down it was what he had expected, but that didn't make it any easier to hear.

'Are there doctors arriving?' he asked. 'With medicine?' He was desperate to know what sort of chance his dad had.

The guard nodded. 'They're on their way. But from what I've seen…' His voice trailed off, and Ben could not persuade him to continue.

It only took a couple of minutes to fly back to the village, and the scene appeared to Ben to be one of organized mayhem. Chinooks seemed to be flying in from all around, and the place was swarming with masked, white-suited men unloading equipment and barking instructions at the frightened-looking villagers who were being herded around into small groups. Signs with the words 'Cordon Sanitaire' had been put up all over the place; tents and a few more solid-looking structures were being erected with surprising speed.

Ben watched in horror as he saw stretcher after stretcher of the ill and the dying being carried into one of those tents. A long, canvas-covered corridor led out the back of it to an area Ben couldn't see. 'Where does that lead?' he asked the guard who had brusquely helped him and Halima down from the chopper.

'You don't want to know,' came the terse reply.

'I do want to know,' Ben shouted at him, his patience wearing thin. 'I'm the one who raised the alarm. I'm the one who got you here. Where does it go?'

The guard seemed to consider that for a moment. Finally he answered. 'Incinerator,' he said. 'They're building it now. We can't risk just burying the bodies.'

Ben let that sink in. 'I need to speak to the person in charge.'

The guard shook his head. 'We have our orders, sir. You need to proceed to the processing area.'

'No,' Ben argued. 'You don't understand. There are people in Kinshasa who knew-'

'The processing area, sir,' the guard said firmly, taking a firmer grip on his rifle.

Ben wasn't going to be bullied. Not now. 'You're either going to let me speak to whoever's in charge, or you're going to have to shoot me.' He jutted his chin out.

The guard appeared to think about it. Eventually he took a radio handset from his belt and spoke into it. 'This is Alpha Nine. I've got the English kid here. He's insisting on speaking to the commander. Over.'

There was a short crackle, and then another voice came over the radio. 'Roger that.'

Thirty seconds later, another masked man approached. 'What's the problem here?'

The guard started to speak, but Ben interrupted him. 'My name's Ben Tracey. I'm the person who informed Dr Sam Garner about the virus, and I'm the person who has just stopped a busload of people from the next village from entering Udok – so please stop fobbing me off.'

'OK, Ben,' the masked man said in a pacifying tone of voice. 'You need to calm down – I know who you are. What can I do for you?'

'Tell me what's happening for a start.'

'We're sealing the village. Everyone who may have come into contact with the virus is being placed into quarantine.' He paused. 'We were warned that you would be here, Ben, but I'm afraid my orders are very explicit. There can be no exceptions.'

'I know that,' said Ben urgently. 'But you have to listen to me. I know things about the virus – information that you have to have. I know where the virus is coming from.'

'OK, son. You'd better tell me what you've got.'

'It's the mine. You've got to seal it. My dad's a scientist and he thinks the reservoir – that's the organism that's harbouring the virus – is down there. It started off just killing bats in the cave, but now it's killing humans. There's no point simply sealing the village – you've got to make sure nobody else ever goes down there and that the infected bats don't fly out.'

Ben couldn't tell if the masked man had taken anything on board. 'Is there anything else,' he simply asked in his American drawl.

'Yes,' Ben stated fiercely. He pointed in the direction of where Suliman was walking to the processing area. 'When you picked us up, that man was trying to kill us, and he's been trying to kill us pretty much since we arrived. He knew about the virus, and he knew I might alert people. Put us in quarantine if you have to, but keep us away from him. He's a psycho.'

'What do you mean, he knew about the virus? Why would he put himself in danger like that? From what I can tell, everyone here thinks it's down to some sort of supernatural mumbo-jumbo.'

'Not Suliman,' Ben insisted. 'You have to believe me.'

'Excuse me, sir,' the guard who had accompanied them in the chopper interrupted.

'Go ahead, soldier.'

'It's true that the men we just picked up were armed, but they claim it was because the kids stole a Land Rover that they were trying to get back.'

The boss looked back to Ben and Halima. 'This true, son?'

'Yes,' Ben said with a sinking feeling, 'but-'

'I don't blame you trying to escape the village, son, but that's not going to happen now.'

'I wasn't trying to escape the village!' Ben shouted. 'I was-'

'OK, I've heard enough,' the commander overruled him. 'Our directions are clear: everyone's to be kept in quarantine. Nobody in there will be armed, so you should be perfectly safe.' He turned and walked away, leaving the guard to push Ben and Halima in the direction of a small group of villagers who were being organized by another of the faceless peacekeepers.

'Just shut down the mine!' Ben shouted over his shoulder. 'Whatever you do, shut down the mine!'

Seething with frustration, they started trudging to where the man had indicated. But Ben was hardly concentrating on where he was going, his attention diverted by the sight of more sick people being stretchered into the canvas tent. He knew perfectly well what he was looking for.

A white face.

He was halfway to the processing area when he saw it. Instantly he ran towards his father, doing his best to keep tears from welling up in his eyes; but before he had run even a few metres, he heard shouts from all around him. Appearing as if from nowhere, two armed peacekeepers stood between Ben and his dad. 'Stand back!' they shouted.

'No,' Ben snapped at them. 'It's OK, it's my dad.'

'No cross-contamination,' the peacekeeper insisted in an emotionless American accent. 'If you do not stand down, I will be forced to shoot. There will not be a second warning.'

Ben stood still. All eyes seemed to be on him. He looked past the guards to where his dad was being carried. Russell Tracey's face was still and pale; Ben watched in desperation as he was carried into the tent. Then he looked back at the peacekeepers, who still had their assault rifles aimed at him. Reluctantly he turned and trudged back to Halima.

'Maybe he is all right,' Halima said without much conviction. Ben didn't reply.

Ahead of them was a disturbance. Ben saw without surprise that Suliman was arguing with someone giving him instructions. Immediately he too was surrounded by two more armed peacekeepers, and eventually he moved, with a surly look but without further complaint, towards a group of people milling around waiting for yet more instructions.