Gadreel regarded her with concern. His wife always entered an almost dream-like state while channelling earth energy, but he had never seen her go so deeply. She had one hand on the chamber’s crystal wall, the other touching the exposed piece inside the humans’ machine. Both glowed, the light pulsing and shifting as if alive. ‘Can you control it?’

‘Yes. It is . . .’ She smiled, the sadistic pleasure of a hunter who had just trapped her prey. ‘Strong. Very strong. The larger the crystal, the stronger it becomes. Had I known I could use the power like this, we would never have needed to go into hiding. We could have defeated our enemies from half the world away!’

‘The humans killed them for us – but now they are our enemies. If we are to save the rest of our people, we must defeat them first.’

‘They murdered our son,’ Sidona snarled. ‘We must do more than defeat them. They must be destroyed. And with this,’ she looked at the machine, ‘I can do it.’ Another cold smile, this time with bared teeth. ‘I will show you. Go to the window and watch.’

He smiled back. ‘Make them pay, my wife.’

She closed her eyes again, focusing her mind on the unseen world surrounding them.

‘Come with me,’ Gadreel ordered the nervous Zan, striding up the stairs. ‘Let us see what your weapon can do!’

Ten floors down – but forty still to go. Eddie hurried down the stairs behind Macy, glad of the ten-year-old’s energy. Whether it would hold out was another matter – and the same could be said of his own. He had done his best to keep himself in shape, but he was still half a century old, and even the fittest body had its limits.

He glanced back. The overweight Cheng was already struggling to keep up. The soldiers, on the other hand, were as fit as he would have expected – just as he had been at their age . . .

A moment of mental chastisement. It didn’t matter how old he was – it was what he did that was important. And he would get everyone out of this mess, somehow—

Another jolt shook the stairs. Macy grabbed the banister. ‘What was that?’

Eddie slowed. No explosions, so it wasn’t another barrage from the fortress. If anything, it seemed to have come from below. He looked down the stairwell, but saw nothing. ‘I don’t know, but we need to keep moving.’ He caught up with her—

The lights went out.

Eddie swore under his breath, stopping and grabbing the banister with one hand as his other found Macy’s shoulder. Thumps and gasps came from behind as the Chinese bumped into each other.