The sea beneath the airship was mostly black-dark, but in places it glowed dimly in giant, slowly fading Vs as giant sea creatures surfaced to breathe or to sieve new levels of the waters for their tiny prey, and so disturbed the light-emitting plankton near the surface.

The island floated high in the breeze-ruffled waters, its base a steeply fluted pillar that extended a kilometre down into the sea’s salty depths, its thin, spire-like mountains thrusting a similar distance into the cloudless air. It too was scattered with lights; of small towns, villages, individual houses, lanterns on beaches and smaller aircraft, most of them come out to welcome the vacuum dirigible.

The two slowly revolving gondola sections slid gradually to a halt, preparatory to docking. People in both segments congregated on the sides nearest the island, for the view. The airship’s system registered the imbalance building up and pumped bubblecarbon spheres full of vacuum from one lot of tanks to another, so maintaining a suitably even keel.

The island’s main town drifted slowly closer, the docking tower bright with lights. Lasers, fireworks and searchlights all fought for attention.

‘I really should go, Tish,’ the drone Gruda Aplam said. ‘I didn’t promise, but I did kind of say I’d probably stop by . . .’

‘Ah, stop by on the way back,’ Tishlin said, waving his glass. ‘Let them wait.’

He stood on the balcony outside one of the lower gondola’s mid-level bars. The drone - a very old thing, like two grey-brown rounded cubes one on top of the other and three-quarters the size of a human - floated beside him. They’d only met that day, four days into the cruise over the Orbital’s floating islands and they’d got on famously, quite as though they’d been friends for a century or more. The drone was much older than the man but they found they had the same attitudes, the same beliefs and the same sense of humour. They both liked telling stories, too. Tishlin had the impression he hadn’t yet scratched the veneer off the old machine’s tales of when it had been in Contact - a millennium before he had, and goodness knew he was considered an old codger these days.

He liked the ancient machine; he’d really come on this cruise looking for romance, and he still hoped to find it, but in the meantime finding such a perfect companion and raconteur had already made him glad he’d come. The trouble was the drone was supposed to get off here and go to visit some old drone pals who lived on the island, before resuming its cruise on the next dirigible, due in a few days’ time. A month from now, it would be leaving on the GSV that had brought it here.

‘But I feel I’d be letting them down.’