For a moment there was silence on the antenna raft, except for a faint creak from the immense supporting cables that held it suspended a hundred metres in the sky. Then Moisevitch continued, so quietly that Floyd had to strain to hear him: 'Has anyone checked Discovery's orbit lately?'

'I really don't know – but I suppose so. Anyway, why bother? It's a perfectly stable one.'

'Indeed. Let me tactlessly remind you of an embarrassing incident from the old NASA days. Your first space station – Skylab. It was supposed to stay up at least a decade, but you didn't do your calculations right. The air drag in the ionosphere was badly underestimated, and it came down years ahead of schedule. I'm sure you remember that little cliffhanger, even though you were a boy at the time.'

'It was the year I graduated, and you know it. But Discovery doesn't go anywhere near Jupiter. Even at perigee – er, perijove – it's much too high to be affected by atmospheric drag.'

'I've already said enough to get me exiled to my dacha again – and you might not be allowed to visit me next time. So just ask your tracking people to do their job more carefully, will you? And remind them that Jupiter has the biggest magnetosphere in the Solar System.'

'I understand what you're driving at – many thanks. Anything else before we go down? I'm starting to freeze.'

'Don't worry, old friend. As soon as you let all this filter through to Washington – wait a week or so until I'm clear -things are going to get very, very hot.'

The dolphins swam into the dining room every evening, just before sunset. Only once since Floyd had occupied the Chancellor's residence had they broken their routine. That was the day of the '05 tsunami, which, fortunately, had lost most of its power before it reached Hilo. The next time his friends failed to turn up on schedule, Floyd would throw the family into the car and head for high ground, in the general direction of Mauna Kea.

Charming though they were, he had to admit that their playfulness was sometimes a nuisance. The wealthy marine geologist who had designed the house had never minded getting wet because he usually wore bathing trunks – or less. But there had been one unforgettable occasion when the entire Board of Regents, in full evening attire, had been sipping cocktails around the pool while awaiting the arrival of a distinguished guest from the mainland. The dolphins had deduced, correctly, that they would get second billing. So the visitor was quite surprised to be greeted by a bedraggled committee in ill-fitting bathrobes – and the buffet had been very salty.

Floyd often wondered what Marion would have thought of his strange and beautiful home on the edge of the Pacific. She had never liked the sea, but the sea had won in the end. Though the image was slowly fading, he could still recall the flashing screen on which he had first read the words: DR FLOYD – URGENT AND PERSONAL. And then the scrolling lines of fluorescent print that had swiftly burned their message into his mind:

REGRET TO INFORM YOU LONDON-WASHINGTON FLIGHT 452 REPORTED DOWN OFF NEWFOUNDLAND. RESCUE CRAFT PROCEEDING TO LOCATION BUT FEAR NO SURVIVORS.

Apart from an accident of fate, he would have been on that flight. For a few days, he had almost regretted the European Space Administration business that had delayed him in Paris; that haggle over the Solaris payload had saved his life.

And now, he had a new job, a new home and a new wife. Fate had also played an ironic role here. The recriminations and inquiries over the Jupiter mission had destroyed his Washington career, but a man of his ability was never unemployed for long. The more leisurely tempo of university life had always appealed to him, and when combined with one of the world's most beautiful locations it had proved irresistible. He had met the woman who was to be his second wife only a month after he had been appointed, while watching the fire fountains of Kilauea with a crowd of tourists.

With Caroline he had found the contentment that is just as important as happiness, and longer lasting. She had been a good stepmother to Marion's two daughters, and had given him Christopher. Despite the twenty-year age difference between them, she understood his moods and could wean him out of his occasional depressions. Thanks to her, he could now contemplate the memory of Marion without grief, though not without a wistful sadness that would remain with him for the rest of his life.

Caroline was throwing fish to the largest dolphin – the big male they called Scarback – when a gentle tickling on Floyd's wrist announced an incoming call. He tapped the slim metal band to quench the silent alarm and forestall the audible one, then walked to the nearest of the comsets scattered around the room.

'Chancellor here. Who's calling?'

'Heywood? This is Victor. How are you?'

In a fraction of a second, a whole kaleidoscope of emotions flashed through Floyd's mind. First there was annoyance: his successor – and, he was sure, principal contriver of his downfall – had never once attempted to contact him since his departure from Washington. Then came curiosity: what did they have to talk about? Next was a stubborn determination to be as unhelpful as possible, then shame at his own childishness, and, finally, a surge of excitement. Victor Millson could be calling for only one reason.

In as neutral a voice as he could muster, Floyd answered:

'I can't complain, Victor. What's the problem?'

'Is this a secure circuit?'

'No, thank God. I don't need them any more.'

'Um. Well, I'll put it this way. You recall the last project you administered?'

'I'm not likely to forget, especially as the Subcommittee on Astronautics called me back to give more evidence only a month ago.'

'Of course, of course. I really must get around to reading your statement, when I have a moment. But I've been so busy with the follow-up, and that's the problem.'

'I thought that everything was right on schedule.'

'It is – unfortunately. There's nothing we can do to advance it; even the highest priority would make only a few weeks' difference. And that means we'll be too late.'

'I don't understand,' said Floyd innocently. 'Though we don't want to waste time, of course, there's no real deadline.'

'Now there is – and two of them.'

'You amaze me.'

If Victor noticed any irony, he ignored it. 'Yes, there are two deadlines – one man-made, one not. It now turns out that we won't be the first to get back to the – er, scene of the action. Our old rivals will beat us by at least a year.'

'Too bad.'

'That's not the worst. Even if there were no competition, we'd be too late. There wouldn't be anything there when we arrive.'

'That's ridiculous. I'm sure I'd have heard if Congress had repealed the law of gravitation.'

'I'm serious. The situation isn't stable – I can't give details now. Will you be in for the rest of the evening?'

'Yes,' Floyd answered, realizing with some pleasure that it must now be well after midnight in Washington.

'Good. You'll have a package delivered within the hour. Call me back as soon as you've had the time to study it.'

'Won't it be rather late by then?'

'Yes, it will be. But we've wasted too much time already. I don't want to lose any more.'

Millson was true to his word. Exactly an hour later a large sealed envelope was delivered by an Air Force colonel, no less, who sat patiently chatting with Caroline while Floyd read its contents. 'I'm afraid I'll have to take it away when you've finished,' the high-ranking messenger boy said apologetically.

'I'm glad to hear it,' Floyd answered, as he settled down in his favourite reading hammock.

There were two documents, the first very short. It was stamped TOP SECRET, though the TOP had been crossed out and the modification endorsed by three signatures, all completely illegible. Obviously an extract from some much longer report, it had been heavily censored and was full of blanks, which made it most annoying to read. Fortunately, its conclusions could be summed up in one sentence: The Russians would reach Discovery long before its rightful owners could do so. As Floyd already knew this, he turned quickly to the second document – though not before noticing with satisfaction that this time they'd managed to get the name right. As usual, Dimitri had been perfectly accurate. The next manned expedition to Jupiter would travel aboard spacecraft Cosmonaut Alexei Leonov.