They stood up. Before heading inside, Jin put a hand on Sam's arm. 'Thanks for not lying to me,' she said.

'Lying to you?'

'By telling me that everything will be all right. Because things are a long way from all right, aren't they? If this infection spreads, things may never be all right again.'

Sam looked at her for a long moment, his face grim.

'Ain't that the truth,' he muttered finally.

Chapter 19.

THE SURVIVOR.

'SOMETHING'S WRONG.'

Logan looked at Purna in surprise. 'You got spidey senses or something? Looks quiet enough to me.'

'That's what I mean,' said Purna. 'Where are the guards?'

From the far side of the clearing they all stared across at the high-security fence and the blocky grey buildings beyond it.

'Maybe they're on a break?' suggested Xian Mei unconvincingly.

Purna shot her a withering look. 'All at the same time?'

'OK, people,' Logan said almost wearily, 'lock and load.'

Guns at the ready, the six of them moved across the clearing, scanning the surrounding jungle for anything unusual.

Purna's verdict was not based purely on the lack of guards. She had tried calling West that morning, without success. It had been decided before they had set out for Mowen's village yesterday that if West's overnight attempts to develop a vaccine proved unsuccessful, Mowen would take Purna, Sam and the rest straight over to the prison island without them first making a pointless detour back to the research facility.

However, West's unavailability had meant they had had to come here first, after all; if it was even possible that a vaccine had been developed then they couldn't afford not to. Purna knew she would be angry if it turned out they had had a wasted journey, but it probably wasn't West's fault. The communications network had not exactly been reliable these past couple of days, and although the phone at the research facility had seemed just to ring out over and over again without reply, that didn't necessarily mean nobody could be bothered to pick up.

They were about five metres away from the security fence when Sam said, 'Aw, shit.'

'What is it, big guy?' asked Logan.

'Purna's right. We got trouble.'

Moving up to the fence, he pointed through the vertical metal slats to a patch of grass several metres away. Lying in the grass, among several pools of blood, was an AK 47.

'Must've been a prison breakout,' said Logan.

'Where do you think they are now?'

'Inside, I guess.'

'Maybe they wandered off into the jungle,' said Xian Mei, looking around nervously.

Purna shook her head. 'The infected don't climb, and there's no other way out.'

'So what's our next move?' asked Sam. 'We go in there after them?'

'Don't see that we've got much choice,' Purna replied. 'But we're not going in there after them. We're going in there looking for the vaccine.'

'If there is one,' Xian Mei whispered, as if to herself.

Purna pulled a face, as if that was a possibility she didn't want to consider.

'We also need to look for survivors,' said Logan. 'Could be they've locked themselves in somewhere the infected can't get to them.'

Purna nodded.

'So how we gonna do this?' asked Sam. 'Who's going in?'

After some discussion, it was decided that Purna, Sam, Logan and Xian Mei would check out the facility while Mowen and Jin would wait outside the perimeter fence with the backpacks of provisions they had all brought along with them.

'Keep your rifle ready, just in case,' Purna advised Mowen.

He looked at her as if she had insulted him. 'I always ready.'

'And look after Jin,' added Sam, glancing at the girl.

Mowen nodded.

Without guards to warn them off, scaling the security fence was relatively easy. They all climbed over at the same time, while Mowen covered them in case of a sudden unexpected appearance by one or more of the infected. Purna was the first to reach the top of the fence and to land, cat-like, on the ground inside the compound. Seconds later they were all inside, moving forward quickly but warily in a tight formation, checking in every direction as they did so.

The first door they came to was slightly ajar and had a bloody handprint smeared across it, close to the ground, as if someone had tripped and had put out a hand to break their fall. There was more blood on the grass around the door, and a lot more just inside the building. From the streaks and spatters on the walls and floor, it looked as though a struggle had taken place, during which the wounded victim had been dragged at least several metres. After the long bloody smear, however, there was nothing but a trail of red spots meandering up the corridor.

Purna stared at the marks for a few seconds, then said, 'Looks as though someone was attacked outside and then the fight spilled over into here.' She pointed at the spots. 'I'm guessing the victim was infected himself and after lying around for a while, eventually stood up and wandered off down the corridor in search of food.'

'If everyone's infected, how many people are we talking about?' asked Xian Mei.

'Couple of dozen,' Purna estimated.

'That's six each,' said Logan. 'No problem.'

'That depends whether they come one at a time or all together,' said Sam.

The words were barely out of his mouth when a trio of dark shapes appeared at the end of the corridor. One of the shapes let out a hideous caterwauling screech and then all three started to run towards them.

Sam barely had time to register that one was a security guard and the other two were Kuruni tribesmen before the shooting began. The corridor reverberated to the deafening rattle of rifle fire, the attacking zombies throwing up their arms in a jerky macabre dance as they were ripped apart.

Within seconds it was over and the infected were lying in a torn heap, blood and lumps of matter trickling down the pock-marked walls.

'Jeez,' said Logan, a slight tremor in his voice, 'that was-'

'Look out!' screamed Xian Mei.

Sam and Logan jerked up their guns in unison. Almost too late Sam realized there had not been three of the infected in the group that had attacked them, but four. The one at the back, a small Kuruni child no older than five or six, had managed to sneak in under the radar. It had evidently escaped unharmed from the hail of bullets, not only because it had been shielded by the three adults but also because most of them had passed over its head.

It came at them now, though, fast as a panther cub but far more deadly. It leaped over the mound of dead zombies and was almost upon them before they could react. Purna raised her rifle and fired just as the child launched itself through the air. The shot ripped the left half of its head and face away in a welter of blood and brains. The impact spun the child round in mid-air, Logan and Xian Mei jumping back as its body hit the wall close to them with a wet smack and slithered to the ground.

'Stay alert,' Purna snapped, barely giving the crumpled body of the child a second glance. 'Don't let your guard down for a moment.'

The rest of them nodded and they moved forward, Sam holding his breath against the rank smell as they cautiously stepped over the slowly spreading pool of blood seeping from under the tangled bodies of the four zombies. He had thought the research facility was cramped before, but now it seemed positively claustrophobic. The ceilings were too low and there were too many intersections; the grey walls seemed to suck in light despite the stark glare of the overheads, and to cast too many shadows.

As they headed for the laboratory, more of the infected suddenly appeared from a door in a corridor to their left. There were six of them this time, and the reflected light made them appear gimlet-eyed, which seemed to bestow them with an eerie, savage intelligence. At their head was a security guard, hunched over like an ape. His blood-streaked upper teeth were bared in a snarl, and the entire left side of his face was an oozing red mask, due to the fact that one of the infected had clearly taken hold of his top lip and wrenched upwards, ripping most of the flesh away. Without eyelids his left eye seemed to bulge and glare as it fixed upon them. Then, snarling and screeching, the six-strong group began to blunder and lope towards them.

Not exactly calmly, but certainly with an efficiency and precision acquired both through practice and necessity, Purna, Sam, Logan and Xian Mei stood their ground and opened fire. The air turned red as the heads of the infected were punctured, shattered, torn apart. The first two zombies the security guard and a Kuruni tribesman went down and the others scrambled over them and were themselves cut down in their turn. Again the whole thing was over in less than a minute, the corridor echoing with the din and stink of battle.

Ten down, Sam thought, then something crashed into the back of him, knocking him to the ground.

He fell forward, landing on his gun. Although the thing at his back was a screeching, slashing dervish of activity, his first fearful thought was that the gun might go off with him lying on top of it. If that happened, then the cartridges would rip into his body like a series of minor explosions, causing untold and almost certainly lethal damage. Above him he was aware of shouting, running, of people crowding around him. The animal-like snarling was right by his ear, then something slashed across his cheek with a stinging shock.

Though he was pinned to the ground with a weight on his back, Sam did his best to shake his attacker from his body. He bucked and wriggled, pistoned back his elbow and felt it connect with something solid and fleshy.

All at once he was aware of the weight being lifted from him, of the spitting and snarling retreating from close by his ear to somewhere further away. Free to move, he rolled to one side, grabbed his gun and pulled it out from under his body. Then he rolled right over on to his back and sat up, pointing his gun at where he judged his attacker to be.

It was a young infected Kuruni woman, blood smeared around her mouth and clogging the nails of her hooked fingers. Xian Mei and Logan had pulled her off his back and were now wrestling with her, holding on to an arm each, trying to evade her snapping jaws. The tribeswoman was writhing and thrashing like an angry snake, and they were clearly finding it difficult to maintain a grip. Puffing out air to clear his head, Sam took aim and pulled the trigger.

The top of the woman's head disintegrated, spattering all three of them with blood and brains. Instantly the zombie went limp, falling back against the wall and sliding to the floor as Logan and Xian Mei let go of her arms.

Grimacing with distaste, Logan brushed clots of blood and gobbets of brain from his face and clothes. 'Way to go, buddy,' he said.

'Sorry,' said Sam, using his sleeve to wipe blood off his forehead.

'Are you OK?' asked Xian Mei.

Sam fingered the slash on his face. He would have an impressive scar there once it healed. 'I guess so. Bruised my ribs when I landed on my gun.'

Purna stepped forward, offered Sam a hand and hauled him to his feet. 'Making a habit of the old hand-to-hand combat, aren't you?' she said with a grim smile.

Sam snorted a humourless laugh. 'Guess I'm just the tastiest of us all.'

'Yeah, you know what? I'm not even remotely jealous,' said Logan.

Suddenly Xian Mei held up a hand. 'Listen everyone.'

They all froze and raised their heads. Faintly they heard someone shouting for help.

'That's Yerema,' said Sam.

'She must have heard the gunfire,' said Logan.

'Guess we'd better go rescue her,' said Sam, and raised his eyebrows at Purna. 'That's getting to be a habit too.'

'It came from that direction,' said Xian Mei, pointing.

'The laboratory,' Purna confirmed. 'If Yerema's still alive, then that's probably where the rest of the infected will be. Remember everyone, there are potentially still around a dozen of them in here with us, so stay alert and be careful.'

Logan gave her a mock-salute, earning himself a disapproving glance, and they moved towards the laboratory.

As they approached the door they could see it was open. Purna put a finger to her lips and crept forward, the others a step or two behind. Yerema was still calling for help, though now that they were right outside the lab they could tell she was still a couple of rooms away. Sam guessed she must be in the cell area and that she had probably locked herself into one of the cages. He wondered if she was the only survivor, and what had happened to West.

As soon as they entered the laboratory his question was answered. West had been torn apart; there were gnawed pieces of him scattered all over the room. His legs, still clad in designer jeans and Timberland boots, were up against the far wall. There was one of his chewed arms, a still-ticking watch around its wrist, on the counter, and a torso, partly clad in a red and black checked shirt like a huge fleshy cushion, in the middle of the floor, trailing guts like stuffing. His head was resting against one of the now-empty animal cages, his surprisingly unmarked face turned towards them. His mouth was open in a frozen scream, his pale blue eyes glaring at them accusingly.

You caused this, he seemed to be saying. You brought them here. I'm dead because of you.

The floor was awash with West's blood and the white walls were covered with it. Some of the equipment had been swept to the floor and smashed, and all the animal cages were open and their occupants gone eaten by zombies, Sam wondered, or fled back into the jungle?

The door on the far side of the laboratory was also open and, as Sam had expected, it was from beyond here that Yerema's voice was coming. There were other sounds in there with Yerema too grunts and snarls and dull metallic thumps.

'Yerema!' Sam shouted.

There was a high-pitched gasp. 'Sam? Is that you?'

'Yeah. Listen, you OK in there?'

As he had expected, she shouted, 'I'm locked in one of the cages. The infected are throwing themselves against the bars, trying to get in.'

'How many of them are down there with you?' Purna shouted.

'I don't know. About ... twelve?'

Purna nodded; it was what she had expected. 'Are there any close to the door?'

'No. They're all trying to get at me.'

Turning to the others, Purna said, 'I'm going in there to draw them out. I want you three to get them in a cross-fire as they emerge but just do me one favour, OK?'

'What's that?' asked Xian Mei.

Purna smiled faintly. 'Try not to be too trigger-happy. Give me time to get clear before you start firing.'

They took up their positions, Logan to the left of the door, Sam in the middle and Xian Mei to the right. Unhesitatingly Purna passed through the open doorway into the cell area, and they heard her descending the steps and striding determinedly along the corridor towards the second door at the far end, her footsteps fading as she got further away. For a minute or so there was silence, then they heard her shouting defiantly, 'Hey, you lot! Why don't you pick on someone your own size?'