To Major Wu’s fury, the helicopter pilot hurriedly took his Z-20 well clear of the battle zone after the two jets were destroyed. He then orbited the city centre four kilometres out, giving those aboard a terrifying grandstand view of the skyscraper’s collapse. The loss of two fighters had deterred the officers at Cangliang from sending any more aircraft, angering her even more.

But now something had turned the tide. Through binoculars, Wu saw an explosion beneath the shimmering dragon’s head – then the fortress went out of control, crashing into a parking lot before struggling back into the air.

There was no doubt that it was damaged. The multispectral ripple of its shield had gone, and it lost height as it fled deeper into the city. ‘They’ve got it!’ she cried. ‘The men from the other chopper – some of them must have survived! They’ve taken it down!’

‘It’s still airborne,’ the co-pilot cautioned.

‘Not for long.’ She switched her headset to communicate with the airbase. ‘This is Major Wu! The UFO is crippled – I repeat, it’s going down. I need ground troops to secure it and make sure none of the monsters escape. Get as many men here as you can, now!’

There was far less resistance to her orders this time. She switched back to the intercom. ‘Take us in closer,’ she told the pilot. ‘And ready the guns!’

‘We need to tell my mother what’s happening,’ said Cheng as his companions watched the fortress disappear behind more towers. He took the laptop from his backpack and unfolded the satellite link.

‘Can’t you just phone her?’ Macy asked.

He shook his head. ‘All civilian telecommunications will have been cut off. If Major Wu didn’t order it, someone at the base will have.’

‘Your government doesn’t want videos of a UFO blowing up half the city all over the Chinese version of Twitter, I guess,’ said Nina.

‘Weibo, and no, it doesn’t. They’re kind of strict about state security. But this uses military channels, so it should still work.’ He set up the antenna, then opened the laptop and started to type.

Eddie turned at the sound of a helicopter, seeing a distant Z-20 pursuing the fortress. ‘That must be Major Wu. Christ, she’s not going after that thing, is she? It’s still dangerous.’

Cheng looked up briefly from the computer. ‘If you blew up its power source, will the guns still work?’

‘I don’t know,’ said Nina. ‘It might depend who’s using them. Anything that requires care and precision and complex manipulation of the earth energy fields, that’s a job for a woman. If it’s just blam-blam blowing crap up, you only need a man.’

‘Things haven’t changed much in a hundred thousand years, have they?’ Eddie said, grinning.

A voice came from the laptop’s speakers: Dr Hui Ling. ‘Ma-!’ said Cheng, relieved.