The forest was less thick here, and if Ben's body had not been so desperately tired they could have run faster. But after a couple of minutes he could go no further. 'Stop!' he tried to say; but all that came out was a hoarse, high-pitched wheeze. Then he bent over and, unable to help himself, started to retch.

He would have been sick, but there was nothing in his stomach to come up.

CHAPTER SEVENTEEN

It took Ben a good fifteen minutes to recover. He sat on the stump of a felled tree, struggling for breath and bent double with pain. Halima sat on a stump too, her wet hair sticking to the side of her face as she gazed at him with a kind of wonder.

Eventually Ben found his voice. 'You OK?' he asked weakly.

Halima nodded with a mysterious smile. 'Yes,' she said. 'I am OK. Thanks to you.' Her eyes seemed to bore straight into him.

Ben found his face reddening, and he was suddenly overcome with the urge to change the subject. 'I wish we could find some dry clothes,' he said, looking down at himself so as to avoid Halima's gaze. The sunlight beneath the trees was too dappled, and the humidity was too intense, for them to dry off.

Halima smiled. 'It will rain soon. Then we will be even wetter, if we do not reach the village beforehand.'

'We'd better go then,' Ben agreed. He forced himself onto his feet, and was alarmed by how stiff his muscles were. Best to keep moving, he thought to himself. If I sit here for too long, I'll never get up.

There was no road as such leading to the village, but Halima led the way confidently enough. Ben tried to ignore the wetness of his shoes, which were causing blisters on his skin as he walked, and it was with a certain sense of satisfaction that he saw the trees thinning out even more. 'Here,' Halima said finally. She sounded subdued.

Ahead of them was a clearing. It was deserted, but it was obvious that there had recently been activity here. It was surrounded on three sides by trees, although on one of those sides the greenery had been crudely hacked away to make room for a rough dirt track. A long pile of earth was mounded up alongside a wide trench; parallel to these were other trenches that had clearly been recently filled in. Ben felt sick as a realization gradually dawned on him – a realization that was confirmed when Halima spoke. 'My mother and father lie here,' she whispered.

Ben looked at her in horror. 'Is this a mass grave?'

Halima nodded mutely, her jaw clenched.

'Why?' Ben breathed.

'I told you, the people from my village are dying quickly. There is not the time or resources to make separate graves for them all.'

Suddenly there was a noise beyond the trees: a vehicle. Ben and Halima scurried to hide behind a bush, and from their hiding place they looked out on to the grave. An old truck trundled up the path, coming to a halt at the top of the trench. As he watched, Ben felt a horrible premonition of what was to come, but somehow he couldn't turn his eyes away. Two men climbed out of the truck, opened up the back and strained as they pulled off a body, one holding the shoulders, the other holding the feet. From this distance Ben couldn't tell if the corpse was male or female; but he could see the skin was black. He felt a sense of guilty relief: it wasn't his dad.

The two men returned to the back of the truck and pulled off another body. Ben blinked, and a shudder passed through him.

It was a body of a child.

The tiny corpse was given no more ceremony than the one that went before; it too was slung into the deep grave, before the men pulled a pair of shovels out of the back of the truck and started to cover the latest occupants in loose dirt. It looked like back-breaking work – clearly the bodies needed to be well covered in order to stop wild animals from digging them up. Soon, though, their work was done and they drove off.

When Ben turned to look at Halima, her face was grim. She muttered something to herself in Kikongo.

'What did you say?' Ben asked.

Halima shook her head. 'It doesn't matter,' she told him.

Ben felt a surge of sympathy for her. What must it be like, he wondered, to know that your parents were rotting in an unmarked grave, just two out of countless forgotten corpses? 'We're going to put a stop to this,' he said calmly.

'How can we?' Halima's eyes were distant, and she spoke as though she had lost hope.

'By stopping the spread of this vi-' He cut himself short. Halima didn't believe in the virus, not really.

But she knew the mine had to close. 'Listen, Halima,' he said, slowly and patiently. 'I have to make this phone call to England. It's the only way the mine is going to be shut down. And you know it has to be shut, don't you?' Halima nodded.

'Good. Because if it isn't, this won't be the only mass grave in your country. There will be thousands of them, in every town and every village. It could be a disaster like the world has never seen. Trust me, I know a thing or two about disasters.'

He let that sink in for a moment.

'Shall we go?' he continued.

Halima smiled thinly as she nodded her head. 'Yes, Ben,' she said. 'Let us go.'

They saw nobody as they hurried away from the graves. Hardly surprising, Ben thought. It's not the sort of place you want to hang around. 'Do you know where Suliman's office is?' he asked after a little while.

'Yes,' Halima stated. 'It is by the mine, not far from here. But his men will be all around – we will not be able to get there without being seen. And what if he is in his office?'

Ben's eyebrows furrowed. Halima was right, of course. They had been concentrating so hard on getting to the village that they had not devised any kind of plan to get to the satellite phone. 'Let's cross that bridge when we come to it,' he said, a bit unconvincingly.

The decision was upon them sooner than expected. Before long they found themselves skirting the edges of the mine. It was busy: dejected-looking workers were trudging around, and guards with the now -familiar AK-47s seemed to be everywhere. It looked to Ben like an impossible situation; as soon as they stepped out into the open they would be seen. And shot, most probably.

Ben chewed on his lower lip in worry. 'What are we going to do?' he whispered to Halima as they crouched down together behind a low bush.

As if in answer to their question, Ben heard a low rumble in the near-distance. It sounded strangely out of place here. 'Was that…?'

A broad smile spread across Halima's face.

'Thunder,' she confirmed. 'The rains are coming.'

'We need to find shelter,' Ben worried.

But Halima was still smiling. 'No,' she said. 'It is not us who will find shelter. Watch.'

Ben could scarcely believe the speed with which the skies darkened. There were no rolling clouds, just an all-pervasive gloom that seemed to stick to everything.

And then it started to rain.

At first the drops were infrequent, but strangely heavy. They splatted on the dusty earth like bullets. Ben watched in wonder as all the men drifting around the mine seemed to disappear into huts and shelters.

Soon enough he saw why.

Ben had never encountered rain like it. It gushed from the sky like a waterfall in the air. Within minutes the dusty roads had turned to fast-moving streams, and their clothes were as heavy with water as they had been when they came out of the river. Rain streamed down their faces and crashed noisily around them. Halima pointed at a hut that was larger than the others. 'That is Suliman's office,' she screamed, struggling to make herself heard above the noise of the rain.

'OK,' Ben yelled back. 'Let's go!'

As the first heavy drops of rain fell upon Abele's face, his sore eyelids opened with difficulty.