Free Survival by Chris Ryan

song. 'It came from further up the trail. An animal. A dying animal.'
'You mean something - killed it?' Paulo shuddered. 'Do we go on?'
Alex stared along the narrow track, trying to see what lay ahead, but the forest crowded right up to the edge of the trail. Finally, he shrugged. 'I think we must,' he said, starting to walk again. 'We have to find water.'
'And the animal?'
Animals mean water,' said Alex, over his shoulder.
Paulo hesitated, then grasped his stick more tightly and followed Alex. 'I hope the others are safe,' he muttered uneasily.

TEN
Amber shrieked loudly, then shrieked again.
'Eeeuuww! Get it off me! Get it off!'
Li rolled her eyes heavenwards and turned to see what the problem was this time. Amber was balancing on one foot in the mangrove swamp and holding the other leg clear of the green, stinking water.
'What?' said Li.
Amber pointed a shaking finger at the back of her knee. A very large leech was hanging there. It was olive green in colour, with lines of small, black dots along its length. The body below the mouth was distended into the shape of a pear, the rounded end full of blood. The leech was pulsing slightly and its glistening skin was streaked with Amber's blood, which was also dripping steadily into the swamp water.
'That's going to attract more of them,' observed Li, pointing to the pink tinged water.
Amber flinched, then turned and scrambled up the gnarled root of a mangrove tree until she could perch clear of the water. Li swung herself up beside Amber with one, easy motion, then bent to look at the leech.
'It's nearly full,' she said, calmly. 'It'll drop off soon.'
'Take if off now!' demanded Amber.
'I can't do that,' said Li. 'We need some heat or alcohol or something to make it let go. If I try to pull it, the head will come off and the jaws will be stuck in your leg. Then it'll get infected and--'
'I want it off now,' moaned Amber.
'Hey! It's your fault we're up to our knees in a mangrove swamp!' snapped Li. 'You're the one who insisted we came back this way!'
She turned away from Amber and pushed her long, black hair away from her sweaty face, trying to figure out when things had started to turn sour. The first part of the morning had gone well. They had worked their way around the coastline until they came to the mangrove swamp. Then they had headed inland, following a game trail and stopping to gather ripe, orange pawpaws and wild figs on the way. The game trail had taken them neatly around the swamp to the base of the headland. From there, it had been mainly hard, uphill walking, with one final, short section of real climbing, which Li had managed easily. Once she reached the top, Li had anchored the nylon line to a rock outcrop and lowered the other end for Amber to tie around her waist with a bowline. To Li's surprise, Amber had climbed slowly but well, following her route almost exactly. Li made sure she kept taking in the rope as Amber climbed, keeping it taut just in case, but it was never really needed.
At the top of the headland, they had discovered a tiny, fresh-water run-off, where they filled the plastic bottle to take back with them. Then they had found a rock to lean against as they rested together, sharing the can of lemonade and looking out to sea. They had scanned the sea again and again but saw only featureless water, stretching to the far horizon. There were no planes, no ships and no other islands.
Discouraged, they had turned their backs on the sea to study the geography of this side of the island. Below and to the east was their lagoon, with the reef beyond. It was the only stretch of sand in sight. The rest of the coastline was a hostile mixture of mangrove swamps and rocky headlands. Behind them the rainforest stretched like a huge green, moving sea and above them the mountain climbed skyward. Li studied the shape and contours of the island for a long time. Finally, she sat back, satisfied that she had worked out and memorized the best route round to the other side