‘Once they built starships here,’ the Curator said. ‘Before hyperdrive, even. They used the worldlet’s own water ice for reaction mass, digging out great pits like that one.’ The quarry he pointed out was a slumped hole in the ground, indistinguishable from a thousand others. ‘When hyperdrive came this place was bypassed for a while. But then, because it was so hidden away and forgotten, the first of the Ascendents came here.’

‘Ascendents?’ Symat asked.

‘Undying,’ Mela said immediately.

The Curator raised a thin eyebrow. ‘They’ve been called many names in their long history - jasofts, pharaohs - few of them complimentary. Ascendents isn’t so bad, I think: we are all their descendants after all . . . Whatever they’re called, I care for them. That’s my vocation! You’ll see, anyhow. You’ll meet them. They want to meet you, Symat.’

Symat tried to absorb that, and tried not to react to Mela’s obvious fear.

The flitter circled this little world rapidly, and soon they once more approached the mast, with the flare of blue light at its tip. Buildings clustered at the base of the tower, while machines like giant beetles dug a pit in the ice that sliced through the pale marks of older workings.

Symat said, ‘This is a rocket, isn’t it? And it’s pushing this moon.’

The Curator nodded. ‘Very perceptive. We’re actually at one spin pole of the moon - a good place to push.’ He pointed. ‘The engines are GUTdrives - one of mankind’s oldest technologies, immensely reliable. The exhaust is plasma, charged matter, the outflow shaped by magnetic fields. And, just like in those ancient starship engines, the stuff of Port Sol itself is being consumed as reaction mass. You can see how the engineering here has churned up the old surface. Aside from Earth itself, Port Sol is probably the system’s key historic site. But Ascendents care little for archaeology.’ He sighed. ‘I suppose you wouldn’t if you could remember it all!’

Mela said, ‘So this is an Ascendent project.’

‘Well, of course. The mass of Port Sol is huge, and by comparison the rocket delivers only a small push. You have to keep shoving for a very long time before you can kick it out of its orbit. But that’s just the sort of long-term, dogged programme the Ascendents excel at.’

The rocket tower dropped behind the horizon, and the flitter swept down towards a plain of ice, heavily melted by the heat of multiple landings. Nearby was a cluster of domes, evidently their destination.

As the ground fled beneath the descending flitter, Symat spotted a slim black pillar, obviously artificial, standing in the middle of what looked oddly like a forest, ‘trees’ sculpted from ice. ‘Look, Mela. A transfer booth! Even here they are escaping.’