‘They chased them across the world,’ the scientist replied. She brought up a map. Dots connected by arrows formed a ragged path from the heart of Africa through the Middle East and into Central Asia. ‘Each point is a reference to a place from the Nephilim records. Most have not been specifically located, only the general region, but a few we have narrowed down to smaller areas.’

‘Like the one near here?’

‘Yes. We believe the fortress is within sixty kilometres. But our aerial surveys have not found any trace.’

‘Which is why we must question him,’ Wu commented pointedly.

‘As you can see,’ Hui continued, ‘the Nephilim travelled a long way to escape their pursuers.’

‘A very long way,’ Nina agreed. ‘But they were still being pursued?’

The Chinese woman nodded. ‘The longest they stayed in one location before Shangdi scouts found them was twenty years. Whenever this happened, they moved on before a larger force could capture them.’

‘Capture them?’ Eddie asked. ‘Not kill them?’

‘The Veteres considered themselves civilised,’ said Nina, giving the word a caustic edge. ‘Abominations or not, the Nephilim were still their offspring. Imprisoning instead of executing would let them feel they had the moral high ground.’ Something she had said earlier came back to her. ‘Wait . . . in the Bible, the Nephilim were supposedly imprisoned for eternity. And they have a way to sleep for eternity – are the two things connected?’

‘We think so,’ Hui told her. ‘What the Nephilim used by choice, the Shangdi imposed on them by force. The Nephilim feared being taken to Tartarus, where they would be trapped in torment beneath the earth, alive but unable to move.’

Nina nodded thoughtfully. ‘A place from Greek and Roman mythology,’ she added for Eddie’s benefit – from Macy’s look of recognition, her daughter had encountered the name in her explorations of ancient legends. ‘A prison at the end of the world for those who challenged the gods, and for the worst sinners. The version in the Book of Enoch is where fallen angels are imprisoned.’

Eddie glanced back towards the laboratory. ‘So that sarcophagus was originally built as a sort of eternal torture chamber? And the Nephilim used them voluntarily?’

‘They might not have had a choice,’ she mused. ‘If it came down to freezing to death in the Antarctic or putting yourself into stasis, even knowing what that meant, in the hope of being rescued later, what would you do?’

‘Put it that way . . . yeah, I’d probably chance the freezer,’ he admitted.

Macy had another question. ‘What was the second thing Gadreel was known for?’

Before Hui could answer, there was a knock at the door. A guard entered and spoke briefly to Wu. ‘He wants us,’ she announced.

Hui quickly switched the screen back to the isolation chamber. Gadreel had stood, donning a robe taken from a previously unnoticed compartment inside the sarcophagus. She rose and signalled for everyone to follow her into the laboratory.