‘Felt good anyway,’ Kirby said. He was about to clamber over the rocks when Ben stopped him.

‘Wait. And give me that before you do anything else stupid with it. You could have got us both killed.’ He snatched the.38 from him.

They waited two minutes, then three, and Ben listened hard. But other than the crackle of the flames from the burning tank, the desert was silent. He guessed that wherever the rest of the Sudanese armoured division were, they weren’t close enough by to worry about-at least, not yet.

After four minutes, Ben decided that he and Kirby were the only living human beings within a wide radius, and he stepped out from behind the rocks and surveyed the smoking battlefield.

He threw a long, regretful look at the ruin of the Toyota. There was nothing left there to salvage. No weapons, no equipment. And no water. The dark patch where their bottles had burst was quickly evaporating on the hot sand. With no vehicle, the only thing between them and a slow, baking death was what little water they carried in their belt canteens.

That was something else he could worry about later. Evening would soon be falling. Dying of thirst would be a more pressing issue in the morning. In the meantime, he had a treasure to find.

He wiped the dust and sweat off his face. ‘Let’s go,’ he sighed to Kirby, and led the way through the canyon towards the ridge. Fifty yards further on, he stepped over the body of the motorcyclist who’d almost made it. The sling of the dead Bedouin’s AK-47 had been snapped by a bullet and the weapon was lying a few feet away. Ben picked it up. The stock was decorated with metal studs and mother-of-pearl insets. The barrel was crushed and bent from a shrapnel impact.

He tossed the useless weapon back down. Walked grimly on.

The sun had sunk below the cleft now, just a shimmering golden rim of its disc visible over the rocks. Without the glare in his eyes, Ben could see the towering rock in more detail. He ran his eyes down its craggy face.

And stopped.

And stared at the cave entrance that hadn’t been there before. The tank’s final shell had carved away a section of the ridge, exposing a jagged black crevice a few metres up its face that before must have been covered with millennia of fallen rock and storm-blown sand.

Kirby had seen it, too. They glanced at one another, and ran. Sand and loose stone slithered underfoot as they clambered up the slope towards the cave entrance. Ben got there first, and peered cautiously into the dark space.

‘We need a torch,’ Kirby panted.

Ben ran back down the slope and trotted back to the motorcyclist’s body. ‘What are you doing?’ Kirby called after him. Ben snatched up the ruined AK rifle and tore the dead man’s robe away. He ripped it into ten long strips, stuffed nine of them in his pocket and wrapped the tenth around the end of the rifle. He ran back up to join Kirby at the cave entrance, took out his Zippo, flipped it open and lit the strip of material.

The improvised torch cast a dull, flickering glow on the rock walls ahead as they moved deeper into the cave. The tunnel was long and winding.

‘We’re going downwards,’ Kirby’s voice echoed.

Ben nodded. The cave was leading them deep underground. The light began to burn out, and he quickly wrapped another strip of cloth around the rifle. They walked on.

From somewhere deep inside the rock came a long, low rumble. Dust and stones showered lightly down from the ceiling. Ben froze and tensed, waiting for a massive cave-in.

It didn’t come. The dust shower stopped and he could breathe again. ‘I don’t think that tank shell did this place any favours,’ he muttered.

The tunnel kept snaking downwards. It was a natural cave, but Ben could see from areas of smoothed wall that someone, somewhere in time, had been here before. Had that someone been Wenkaura, leading his expedition deep under the ridge, a procession of men carrying caskets of treasure to a place where the heretic pharaoh could never find it?

‘It seems to go on forever,’ Kirby whispered.

‘There’s a bend up ahead,’ Ben said.

A few metres on, the claustrophobic atmosphere of the narrow tunnel suddenly seemed to lift, as though a bigger space had opened up around them. Ben wrapped more cloth around the dying torch and the flame burned brighter. He raised the flickering light over his head.

‘Sweet Jesus, look at this,’ Kirby murmured.

Chapter Fifty-Four

The scene ahead in the torchlight was breathtaking. They were standing at the opening of an underground cavern the size of the largest of cathedrals. The fire glittered off weird and wonderful rock formations.

‘This is fantastic,’ Kirby said, stepping forward.

‘Careful,’ Ben said, stopping him. He shone the torch downwards.

‘Whoops,’ Kirby breathed.

Below them was a deep abyss, falling away into blackness. Massive pointed stalagmites jutted up from the depths like huge stakes, waiting to impale anyone who fell into the chasm. Ben raised the torch higher, and the orange light flickered off great craggy stalactites that hung down from the cavern’s ceiling a hundred feet above them.

‘Looks like giant fangs,’ Kirby whispered in awe. ‘Like an enormous mouth. A shark’s mouth.’

‘Not a shark,’ Ben said. ‘A crocodile. You’re looking at the teeth of Sobek, the crocodile god. “Pass through the teeth of Sobek, and you will discover.”’

Kirby gasped at the realisation. ‘But how the hell do we get across?’

Ben stepped towards the edge and the torchlight glinted off something in front of him. A rope bridge, spanning the void, stretched far into the darkness ahead. Ben put out his hand and his fingers closed around the thick, taut rope. It felt strong and dry in his fist.

‘This way,’ he said.

‘No way,’ Kirby protested. ‘It’s thousands of years old. It’ll never take our weight.’

Ben stepped out onto the bridge. The wooden slats were cracked and grey with age, and the creak of the ancient ropes echoed through the cavern. But it held. He took another step. He was standing right over the abyss now. He turned to Kirby. ‘Are you coming or what?’

Kirby hesitated.

‘Fine.’ Ben took another step. ‘Then I’ll find the treasure myself.’

‘Not on your life,’ Kirby said, following quickly behind. The bridge creaked and swayed as they made their way towards the darkness.

Another deep rumble echoed through the cavern. Stone grinding on stone. Millions of tons of pressure bearing down above them. Ben glanced up at the jagged ceiling and sucked his breath in between his teeth. Something was not right up there. Something fundamental within the structural integrity of the rock had been dislodged by the enormous impact of the tank shell. Maybe it was nothing. Or maybe it would all come crashing down at any moment and this place would be their tomb. There was only one way to find out, and only one way forwards.

‘I feel like I’m walking into hell,’ Kirby said shakily behind him.

‘Maybe you are,’ Ben said.

Another grinding rumble from above, and a shower of small rocks fell from the ceiling. One shattered off a stalagmite. The rest dropped away into nothing. It was a long, long way down.

From somewhere below in the abyss came another sound. The distant rush of fast-moving water. An underground river, an ancient relic from the days when the Sahara desert had been a lush, green paradise.

The crossing of the rope bridge seemed like an eternity, but eventually they reached the far side. Kirby took the last few steps at a run. The sweat was shining off his face in the torchlight. ‘Thank Christ that’s over.’

‘Until you have to cross the other way,’ Ben said.

‘I really needed to be reminded of that.’

Ben didn’t reply. He was already pushing on into the tunnel, wrapping another piece of cloth around the torch as he went.