He froze. The pack must be some sort of demolition charge; it was big enough to contain several dozen kilograms of high explosive. That would reduce himself, Macy and Wu to their component atoms and blast a big hole in Uluru’s innards if it went off . . .

If it went off. Modern explosives were specifically designed for stability – C4 could be dropped into burning petrol or blasted with a shotgun and still not detonate. If one bullet hadn’t set it off, more wouldn’t either.

It was safe – which meant Wu wasn’t. He moved to take another shot—

‘No, Daddy!’ Macy cried, desperately grabbing his gun hand. ‘A nuclear bomb!’

That made him pull back. ‘You what?’

‘She is right,’ Wu said, voice strained. ‘A sixty-kiloton nuclear demolition charge. And . . . I have just activated it.’

‘Well, that was pretty bloody stupid,’ said Eddie. Was she telling the truth? She sounded sincere. ‘Because you’ll be next to it when it goes off.’

‘There was always a chance that we would not return from this mission. We accepted that. It was worth it to wipe out those creatures.’ She almost spat the word. ‘Which will happen in . . . twenty-nine minutes.’

‘Oh great, a ticking clock,’ he said sarcastically, trying to hide his concern. ‘You just got shot twice, and you must be losing blood – think you can stay conscious for that long?’

‘Only I can stop the countdown. And there is no torture you can use to make me. But if you try anything and I am still awake, I will detonate it manually.’

He caught himself before saying, ‘So what’s stopping you?’ There was nothing stopping her – and if she had to, she would push the button. He had to neutralise her. But how, without being gunned down himself?

Blindly hosing the tunnel with automatic fire wouldn’t work. He had to be certain of killing her—

The dead man. If he had grenades, the stand-off would be over in moments. Wu would be killed, but nuclear bombs were precision instruments. Even a grenade explosion was more likely to damage than detonate.

‘Macy,’ he whispered, pointing to the dead man’s flashlight, ‘grab that torch. Then go down into the room at the bottom and find Barney. He’s hurt, but he should be able to look after you. He’s near the wall on the right about halfway along.’

‘What about the bad guys?’ she said.

‘They’re all dead.’ She made a frightened sound. ‘Just . . . try not to look at them,’ he said in a feeble attempt at reassurance.

It didn’t work. ‘Where’s Mom?’ Macy asked, even more afraid.

‘Other side of the shaft. She’s okay – I hope. Now, get the light and find Barney.’

‘What about the bomb?’

‘I’ll sort out the bomb. Go on!’

He squeezed her hand. She reluctantly descended and picked up the torch, giving him a last look before continuing.