Cheng chuckled – then froze as if worried Wu had overheard. But the Chinese officer showed no reaction.

Nina’s own smile quickly vanished. ‘So you did all this in the hope that I’d find the fortress and activate the key for you,’ she said to Cheng. ‘How long have you been planning it?’

‘Ever since we got the key,’ he replied.

‘Stapper was rescued, what, four months ago?’ He nodded. ‘Wait, the semester started less than two months ago! Were you already enrolled, or did someone throw a lot of money around to get you a place?’

‘I’m afraid it was the money thing.’

Nina did not hide her disapproval. ‘So somebody who actually wanted to be an archaeologist lost their place so you could play international spy?’

‘I really do want to be an archaeologist!’ he insisted. ‘I was going to study in Beijing. But when we found the key, you were the only person we knew who could activate it, based on your experiences with Excalibur and the vault in Turkey – so we came up with a plan to get you to do that.’

‘Good plan,’ Eddie scoffed. ‘It almost got us killed – it almost got you killed.’

‘And other people did die because of it,’ Nina added angrily. ‘Their deaths were your fault!’

Cheng was abashed. ‘I’m . . . I’m sorry. But it did work. So . . .’

‘So here we are. You got this,’ she tapped the key, ‘you got an intact sarcophagus complete with occupant – and you got me. Now what are you intending to do with your new collection?’

He had still not recovered from her verbal lashing, keeping his eyes lowered. ‘We want you to open the sarcophagus so we can learn how it works. We found several like it in the Gobi, but they were broken, like all the other Nephilim technology. The theory is that the crystals were damaged by neutron radiation, but nobody knows for certain. But now we have an intact sarcophagus, we can find out.’

‘What do you want it for?’ Eddie asked.

Cheng looked up at him. ‘If we can put people into suspended animation, we can send them into space, to other planets! And there are many medical uses too. A critically wounded person can be put into stasis until they reach hospital, or someone suffering from a disease could be frozen until it can be cured.’

‘All very noble,’ said Nina scathingly. ‘And what about the other technology you found? If it’s like what was in the iceberg, some of them are weapons. Do you want to use the key to make them work too?’

Before she could press him further, the plane’s engine note changed. Wu approached them. ‘We are coming in to land,’ she announced, collecting the key. ‘Take your places.’ Cheng’s laptop was on a table across the aisle; he switched seats with a hint of relief. Wu returned to her own position.