'Slow down' said the Wingmaster, 'I can't keep up with you,'

Poole straightened out, then attempted a slow roll. He felt light-headed as well as light-bodied (less than ten kilograms!) and wondered if the concentration of oxygen had been increased.

This was wonderful – quite different from zero gravity, as it posed more of a physical challenge. The nearest thing to it was scuba diving: he wished there were birds here, to emulate the equally colourful coral fish who had so often accompanied him over tropical reefs.

One by one, the Wingmaster put him through a series of manoeuvres – rolls, loops, upside-down flying, hovering.

Finally he said: 'Nothing more I can teach you. Now let's enjoy the view.'

Just for a moment, Poole almost lost control – as he was probably expected to do. For, without the slightest warning, he was surrounded by snow-capped mountains, and was flying down a narrow pass, only metres from some unpleasantly jagged rocks.

Of course, this could not be real: those mountains were as insubstantial as clouds, and he could fly right through them if he wished. Nevertheless, he veered away from the cliff-face (there was an eagle's nest on one of its ledges, holding two eggs which he felt he could touch if he came closer) and headed for more open space.

The mountains vanished; suddenly, it was night. And then the stars came out – not the miserable few thousand in the impoverished skies of Earth, but legions beyond counting. And not only stars, but the spiral whirlpools of distant galaxies, the teeming, close-packed sun-swarms of globular clusters.

There was no possible way this could be real, even if he had been magically transported to some world where such skies existed. For those galaxies were receding even as he watched; stars were fading, exploding, being born in stellar nurseries of glowing fire-mist. Every second, a million years must be passing...

The overwhelming spectacle disappeared as quickly as it had come: he was back in the empty sky, alone except for his instructor, in the featureless blue cylinder of the Aviary.

'I think that's enough for one day,' said the Wingmaster, hovering a few metres above Poole. 'What scenery would you like, the next time you come here?'

Poole did not hesitate. With a smile, he answered the question.

He would never have believed it possible, even with the technology of this day and age. How many terabytes – petabytes – was there a large enough word? – of information must have been accumulated over the centuries, and in what sort of storage medium? Better not think about it, and follow Indra's advice: 'Forget you're an engineer – and enjoy yourself.'

He was certainly enjoying himself now, though his pleasure was mixed with an almost overwhelming sense of nostalgia. For he was flying, or so it seemed, at an altitude of about two kilometres, above the spectacular and unforgotten landscape of his youth. Of course, the perspective was false, since the Aviary was only half a kilometre high, but the illusion was perfect.

He circled Meteor Crater, remembering how he had scrambled up its sides during his earlier astronaut training. How incredible that anyone could ever have doubted its origin, and the accuracy of its name! Yet well into the twentieth century, distinguished geologists had argued that it was volcanic: not until the coming of the Space Age was it – reluctantly – accepted that all planets were still under continual bombardment.

Poole was quite sure that his comfortable cruising speed was nearer twenty than two hundred kilometres an hour, yet he had been allowed to reach Flagstaff in less than fifteen minutes. And there were the whitely-gleaming domes of the Lowell Observatory, which he had visited so often as a boy, and whose friendly staff had undoubtedly been responsible for his choice of career. He had sometimes wondered what his profession might have been, had he not been born in Arizona, near the very spot where the most long-enduring and influential of Martian fantasies had been created. Perhaps it was imagination, but Poole thought he could just see Lowell's unique tomb, close to the great telescope, which had fuelled his dreams.

From what year, and what season, had this image been captured? He guessed it had come from the spy satellites which had watched over the world of the early twenty-first century. It could not be much later than his own time, for the layout of the city was just as he remembered. Perhaps if he went low enough he would even see himself...

But he knew that was absurd; he had already discovered that this was the nearest he could get. If he flew any closer, the image would start to breakup, revealing its basic pixels. It was better to keep his distance, and not destroy the beautiful illusion.

And there – it was incredible! – was the little park where he had played with his junior and high-school friends. The City Fathers were always arguing about its maintenance, as the water supply became more and more critical. Well, at least it had survived to this time – whenever that might be.

And then another memory brought tears to his eyes. Along those narrow paths, whenever he could get home from Houston or the Moon, he had walked with his beloved Rhodesian Ridgeback, throwing sticks for him to retrieve, as man and dog had done from time immemorial.

Poole had hoped, with all his heart, that Rikki would still be there to greet him when he returned from Jupiter, and had left him in the care of his younger brother Martin. He almost lost control, and sank several metres before regaining stability, as he once more faced the bitter truth that both Rikki and Martin had been dust for centuries.

When he could see properly again, he noticed that the dark band of the Grand Canyon was just visible on the far horizon. He was debating whether to head for it – he was growing a little tired – when he became aware that he was not alone in the sky. Something else was approaching, and it was certainly not a human flyer. Although it was difficult to judge distances here, it seemed much too large for that.

Well, he thought, I'm not particularly surprised to meet a pterodactyl here – indeed, it's just the sort of thing I'd expect. I hope it's friendly – or that I can outfly it if it isn't. Oh, no!

A pterodactyl was not a bad guess: maybe eight points out of ten. What was approaching him now, with slow flaps of its great leathery wings, was a dragon straight out of Fairyland. And, to complete the picture, there was a beautiful lady riding on its back. At least, Poole assumed she was beautiful. The traditional image was rather spoiled by one trifling detail: much of her face was concealed by a large pair of aviator's goggles that might have come straight from the open cockpit of a World War I biplane.

Poole hovered in mid-air, like a swimmer treading water, until the oncoming monster came close enough for him to hear the flapping of its great wings. Even when it was less than twenty metres away, he could not decide whether it was a machine or a bio-construct: probably both.

And then he forgot about the dragon, for the rider removed her goggles.

The trouble with cliche´s, some philosopher remarked, probably with a yawn, is that they are so boringly true.

But 'love at first sight' is never boring.

Danil could provide no information, but then Poole had not expected any from him. His ubiquitous escort – he certainly would not pass muster as a classic valet – seemed so limited in his functions that Poole sometimes wondered if he was mentally handicapped, unlikely though that seemed. He understood the functioning of all the household appliances, carried out simple orders with speed and efficiency, and knew his way about the Tower. But that was all; it was impossible to have an intelligent conversation with him, and any polite queries about his family were met with a look of blank incomprehension. Poole had even wondered if he too was a bio-robot.