The Land Cruiser returned after a few minutes, stopping outside the cave. The two men opened its rear to lift out the crate, now stripped of its parachute.

‘What’s that?’ asked Sandra.

‘The end of this war,’ was Wu’s cryptic answer as she came back outside. She switched off the tracking device and opened the crate. A check of its contents, then she called to the larger of the two men: ‘Liu!’

With some effort, Liu pulled out what Macy at first thought from its straps was a large backpack. But as he put it on, she saw that the canvas-shrouded object was shaped like a squat barrel, about two and a half feet tall. A box, also hidden inside a custom-fitted canvas cover, protruded from its rear.

‘I don’t like the look of that,’ muttered Sandra.

‘Nor do I,’ Macy replied. ‘What is it? A bomb?’

‘You are very perceptive,’ the major replied. ‘Yes, it is a bomb. Specifically, a sixty-kiloton tactical nuclear device.’

Macy gasped.

‘A – a nuke?’ said Sandra, appalled. ‘You’ve brought a bloody nuke to Uluru? Are you crazy?’

‘The Nephilim are a threat not only to my country, but to the entire world,’ said Wu. ‘They must be destroyed. We do not know exactly what is beneath the rock, or how many more Nephilim are down there. There could be thousands, and they have weapons of immense power.’ Her expression somehow became even harder. ‘But so do we. Whatever is down there will be completely destroyed.’

‘But my mom and dad are down there too!’ Macy shouted.

‘We are not on a suicide mission. If they cooperate, they will have the chance to leave with us before the bomb goes off. As will you.’

The ten-year-old stared at her. ‘I don’t trust you,’ she finally said.

‘I don’t care,’ was the blunt reply. ‘Now, you will come with us – or I will shoot you both.’

‘We don’t have a choice, do we?’ Sandra said bitterly.

‘No. You do not.’

The Australian took Macy’s hand as the group headed for the entrance. Torches and tactical lights on their weapons were switched on. Wu took the lead, the man with the bomb at the rear – and Macy and Sandra sandwiched helplessly in the middle as they descended.

Nina led the way deeper. It was hard to judge exactly how far down they had gone, but she estimated several hundred feet. The route became more tricky to follow as side passages branched off it, but the job of navigating the labyrinth had been done for them. The dust of ages on the floor had been stirred up by the Nephilim, who had faced the same decisions: which tunnel to take? ‘The one with the most footprints,’ Barney observed acerbically.