The main event began. One by one the Dancers leapt from their platforms. They were allowed no aids; they followed simple low-gravity parabolas that arched between one floating platform and the next. But the art was in the selection of that parabola among the shifting, shivering ice haloes - which were, of course, invisible to the Dancers - and in the way you spun, turned, starfished and swam against that background.

As one Dancer after another passed over the dome, ripples of applause broke out around the amphitheatre. Glowing numerals and Virtual bar graphs littered the air in the central arena; the voting had already begun. But the sheer beauty of the Dance silenced many of the spectators, as the tiny human figures, naked and lithe, spun defiantly against the stars.

Here, at last, was Lieta herself, ready for the few seconds of flight for which she had rehearsed for four years. Faya remembered how it used to feel, the nervousness as her body tried to soar - and then the exhilaration when she succeeded, one more time.

Lieta’s launch was good, Faya saw, her track well chosen. But her movements were stiff, lacking the liquid grace of her competitors. Lieta, her little sister, was already thirty years old, and one of the oldest in the field; and suddenly it showed.

At the centre of the arena a display of Lieta’s marks coalesced. A perfect score would have showed as bright green, but Lieta’s bars were flecked with yellow. A Virtual of Lieta’s upper body and head appeared; she was smiling bravely in reaction to the scores.

‘There is grey in her hair,’ murmured Luru. ‘Look at the lines around her eyes, her mouth. You have aged better than your ten-years-younger sister. You have aged less, in fact. There is no grey in your hair.’

Faya wasn’t sure how to respond. She looked away, disturbed.

‘Tell me why you gave up the Dance. Your performances weren’t declining, were they? You felt you could have kept going for ever. Isn’t that true? But something worried you.’

Faya turned on her in irritation. ‘Look, I don’t know what you want—’

‘It’s a shock when you see them grow old around you. I remember it happening to me, the first time - long ago, of course.’ She grinned coldly.

‘You’re frightening me.’ Faya said it loud enough to make people stare.

Luru stood. ‘I’m like you, Faya Parz. The same blood. You know what I’m talking about. When you need to see me, you’ll be able to find me.’

Faya waited in her seat until the Dance was over, and the audience had filed away. She didn’t even try to find Lieta, as they’d arranged. Instead she made her own way up into the dome.