‘It is artificial,’ she said. ‘The sphere. It must be.’

‘Yes. Surely no natural process could wrap up a star so neatly. And if it is artificial, who do you imagine might be responsible?’

‘The Xeelee,’ she said immediately. Involuntarily she glanced up at the crowded stars, bright and vivid here, five thousand light years from Earth. In the hidden heart of the Galaxy mankind’s ultimate foe lurked; and surely it was only the Xeelee who could wield such power as this.

There was a change in the darkness ahead. She saw it first as a faint splash of light near the horizon, but as the flitter flew on that splash opened out into a rough disc that glowed pale blue-green. Though a speck against the face of the masked star, it was sizeable in itself - perhaps as much as a hundred kilometres across.

The flitter came to rest over the centre of the feature. It was like a shard of Earth, stranded in the night: she looked down at the deep blue of open water, the mistiness of air, the pale green of cultivated land and forest, even a greyish bubbling that must be a town. All of this was contained under a dome, shallow and flat and all but transparent. Outside the dome what looked like roads, ribbons of silver, stretched away into the dark. And at the very centre of this strange scrap of landscape was a shining sheet of light.

‘People,’ Dano said. ‘Huddling around that flaw in the sphere, that lake of light.’ He pointed. ‘I think there’s some kind of port at the edge of the dome. You’d better take the flitter down by hand.’

Pala touched the small control panel in front of her, and the flitter began its final descent.

They cycled through a kind of airlock, and emerged into fresh air, bright light.

It wasn’t quite daylight. The light was diffuse, like a misty day on Earth, and it came not from the sky but from the ground, to be reflected back by mirrors on spindly poles. The atmosphere was too shallow for the ‘sky’ to be blue, and through the dome’s distortion Pala saw smeared-out star fields. But the ‘sky’ contained pale, streaky clouds.

A dirt road led away from the airlock into the domed ecology. Looking along the road Pala glimpsed clusters of low buildings, the green of forest clumps and cultivated fields. She could even smell wood smoke.

Dano sniffed. ‘Lethe. Agriculture. Typical Second Expansion.’

This pastoral scene wasn’t a landscape Pala was familiar with. Under Coalition ideology Earth was dominated by sprawling Conurbations, and fields in which nanotechnologies efficiently delivered food for the world’s billions. Even so this was a human scene, and she felt oddly at home here.