The Curator shook his head. ‘If this Snowflake weapon is capable of such a remarkable feat, why not turn it on the Xeelee? We could scatter their fleets of nightfighters like swatting flies.’

‘We? ’ Luru mocked him. ‘For a shell of a programme with no personality, you have stored up a lot of aggression, Curator.’

He scowled at her taunting, and Symat could see centuries of bitterness in his expression. ‘Why not just answer the question?’

‘We are done with fighting. After all this time, perhaps we humans have learned a little wisdom - and humility.’ She squinted up at the sky. ‘We humans took on the Xeelee. Remarkable when you think about it: savannah apes against a supergalactic power. We did them some damage, we drove them out of the Galaxy. But the Xeelee are far more than we ever were; we could never defeat them. And we barely noticed the true enemy, a foe of both ourselves and the Xeelee and everything made of baryonic matter, matter like ourselves—’

‘Dark matter,’ said Mela. ‘The photino birds in the sun.’

‘In every sun - yes, child. You mayflies encountered them in the deep past, even found them in the core of Earth’s sun, and you forgot about them. You found them again later, out in the halo of the Galaxy, where dark matter dominates - the Xeelee were already fighting them there, long before our war for the Galaxy - and again, in a generation or two, you forgot what you saw. You are so infuriatingly transient!

‘Well, we can’t fight the photino birds. We never could. Perhaps even the Xeelee can’t, but they are trying. There is evidence that the Xeelee are engaged in supergalactic projects, stupendous in scale - some long-forgotten explorers told tantalising tales.

‘But it doesn’t matter. We humans are trapped, here in Sol system itself, between two immense forces, the destruction of the sun, and the extinguishing of the stars. Yes, Curator, we could wield our last sword and cut off a few more limbs. But we can’t win. So I think it’s better we simply vacate the stage, don’t you?

‘I believe my solution is the right one. The Guardians can do this, if they have the will - and if they are ordered to. But I can’t give that order.’

Symat whispered, ‘Which is where I come in, is it?’