Eventually she said, 'I've got an idea.'
'Make it a good one,' replied Logan.
She outlined her plan to them, pointing out the landmarks she was referring to. When she had finished, Logan laughed quietly.
It was an incredulous laugh rather than a happy one. 'You're fucking crazy, you know that?' A brief smile fluttered at her lips.
'That's why you love me.' She tapped Logan's backpack.
'Lucky we brought plenty of ammo with us.'
After a couple of deep breaths, she said, 'Ready?' 'No,' said Logan.
'But let's do it anyway.' 'OK. On the count of three. One. Two. Three!'
Readying their weapons, they broke cover, each of them running as fast as they could.
Purna and Logan to the right, Sam to the left, like a SWAT team spreading out to cover the area.
They were halfway to each of their individual destinations when they were spotted. Sam, the pounding of his heart filling his ears, was aware of heads turning in his direction, shapes peeling away from the crush of semi-naked bodies crowding around the trees at the far end of the village and lurching towards him.
When several of the infected let out blood-curdling shrieks in unison, prior to breaking into shambling, long-legged sprints, the shock was almost enough to make him lose his footing.
A jolt went through his body, powerful as electricity, and he felt himself stumble, his right knee crumpling at the sudden unexpected weight.
No, he told himself, and the sheer terror of what would happen to him if he went down was enough to keep him going. He turned and let off a few shots, felling the most rapidly advancing of the zombies, before darting between two huts.
Just beyond them was the tree Purna had pointed out to him, and Sam saw immediately that she had chosen well.
Swinging the rifle over his shoulder on its adjustable strap, he leaped at the lowest branches of the tree and began to haul himself up.
He found his hand-holds and lifted his right leg to a higher branch, and was just about to lift his left foot too when it was seized from below.
He looked down to see a woman, her eyes glaring and yellow, her face demonic with rage, clutching his blood-stained Reebok in both hands.
Then he felt pain as her head darted forward and she sank her teeth right through his jeans and into his calf.
'Fuck!' he yelled, the bright white shock of the pain enough to give him a surge of adrenaline. He wrenched his left leg upwards with such force that his foot popped clean out of its shoe, leaving it clutched in the zombie's hands.
The zombie regarded the empty shoe almost comically for a second, then allowed it to drop to the ground.
By the time she raised her head and clawed up towards Sam, he was out of her reach. He found a branch wide enough and strong enough to take his weight and lay across it for a moment, leaning back on his backpack, panting and shaking.
Below him, through a shifting canopy of leaves, he could see zombies already congregating, snarling in what he fancied was frustration, their bloodied fingers scrabbling ineffectually at the tree trunk.
He might have lost a shoe, but at least he hadn't lost his gun or his pack full of ammo – or, indeed, his life. His calf where he'd been bitten was stinging like fuck, though, enough to make him feel ill and faint.
He wrapped his arms around the branch he was draped across and clung on desperately, fearful for a moment that he might pass out and plunge to the ground below.
His forehead was oozing sweat and his heart was like muffled but persistent thunder in his ears. It took several seconds before he realized that someone was shouting his name.
He looked up groggily.
At first, his vision was nothing but a confusion of waving leaves and blinding flashes of sunlight.
The sound penetrated the fog in his mind, enabled him to get his bearings, and eventually he shuffled upright and through a gap in the branches saw Logan sitting high up in his own tree about thirty meters away, behind a bunch of huts on the far side of the clearing.
'Hey!' Sam shouted, his voice thick and a little slurred. 'Fuck, man,' Logan yelled back, sounding pissed off, 'what you been doing? Taking a nap?' 'Kinda,' shouted Sam.
'I got bit. Think I phased out for a moment.' 'You OK?' shouted Purna, the direction of her voice enabling Sam to pinpoint her halfway up a tree forty meters to Logan's left.