Hama felt a fierce anger burn - anger, and a new certainty. ‘Once again aliens have walked into our system, for their own purposes, and we can do nothing to stop them. This mustn’t happen again, Nomi. You know, perhaps the Qax were right to attempt the Extirpation. If we are to survive in this dangerous universe we must remake ourselves, without sentiment, without nostalgia, without pity. Let this be an end - and a beginning, a new Day Zero. History is irrelevant. Only the future is important.’ He longed to be gone from this place, to bring his hard new ideas to the great debates that were shaping the future of humankind.

‘You’re starting to frighten me, my friend,’ Nomi said gently. ‘But not as much as that.’

Now the Xeelee nightfighter itself came climbing above the shattered fog of the horizon. Somehow in his ardour Hama had forgotten this mortal peril. The nightfighter was like an immense, black-winged bird. Hama could see crimson Starbreaker light stab down again and again into the passive, defenceless ice of Callisto. The shuddering of the ground was constant now, as that mass of shattered ice and steam rolled relentlessly towards them.

Nomi grabbed him; holding each other, they struggled to stay on their feet as ice particles battered their faceplates. A tide of destruction spanned Callisto from horizon to horizon. There was, of course, no escape.

And then the world turned silver, and the stars swam.

Hama cried out, clinging to Nomi, and they fell. They hit the ice hard, despite the low gravity.

Nomi, combat-hardened, was on her feet immediately. An oddly pink light caught her squat outline. But Hama, winded, bewildered, found himself gazing up at the stars.

Different stars? No. Just - moved. The Xeelee ship was gone, vanished.

He struggled to his feet.

The wave of vapour and ice was subsiding, as quickly as it had been created; there was no air here to prevent the parabolic fall of the crystals back to the shattered land, little gravity to prevent the escape of the vapour into Jovian space. The land’s shuddering ceased, though he could feel deep slow echoes of huge convulsions washing through the rigid ground.

But the stars had moved.

He turned, taking in the changed sky. Surely the shrunken sun was a little further up the dome of sky. And a pink slice of Jupiter now showed above the smoothly curved horizon, where none had shown before on this tide-locked moon.

Nomi touched his arm, and pointed deep into the ice. ‘Look.’

It was like some immense fish, embedded in the ground, its spreadeagled black wings clearly visible through layers of dusty ice. A red glow shone fitfully at its heart; as Hama watched it sputtered, died, and the buried ship grew dark.