'Christine? You came back so soon...?' It seemed to Johnson that she had left only a few minutes earlier. He remembered waving goodbye to her and sitting down to finish his fruit and admire the giant butterfly, its wings like the painted hands of a circus clown.

'Johnson I've been away for a week.' She held his shoulder, frowning at the unstable wall of rotting vegetation that towered a hundred feet into the air. Cathedrals of flowerdecked foliage were falling into the waters of the lagoon.

'Johnson, help me to unload the stores. You don't look as if you've eaten for days. Did you trap the birds?'

'Birds? No, nothing yet.' Vaguely Johnson remembered setting the traps, but he had been too distracted by the wonder of everything to pursue the birds. Graceful, feathertipped wraiths like gaudy angels, their crimson plumage leaked its ravishing hues onto the air. When he fixed his eyes onto them they seemed suspended against the sky, wings fanning slowly as if shaking the time from themselves.

He stared at Christine, aware that the colours were separating themselves from her skin and hair. Superimposed images of herself, each divided from the others by a fraction of a second, blurred the air around her, an exotic plumage that sprang from her arms and shoulders. The staid reality that had trapped them all was beginning to dissolve. Time had stopped and Christine was ready to rise into the air.

He would teach Christine and the child to fly.

'Christine, we can all learn.'

'What, Johnson?'

'We can learn to fly. There's no time any more everything's too beautiful for time.'

'Johnson, look at my watch.'

'We'll go and live in the trees, Christine. We'll live with the high flowers...'

He took her arm, eager to show her the mystery and beauty of the sky people they would become. She tried to protest, but gave in, humouring Johnson as he led her gently from the beachhouse to the wall of inflamed flowers. Her hand on the radiotransmitter in the inflatable, she sat beside the crimson lagoon as Johnson tried to climb the flowers towards the sun. Steadying the child within her, she wept for Johnson, only calming herself two hours later when the siren of a naval cutter crossed the inlet.

'I'm glad you radioed in,' the US Navy lieutenant told Christine. 'One of the birds reached the base at San Juan. We tried to keep it alive but it was crushed by the weight of its own wings. Like everything else on this island.'

He pointed from the bridge to the jungle wall. Almost all the overcrowded canopy had collapsed into the lagoon, leaving behind only a few of the original palms with their bird traps. The blossoms glowed through the water like thousands of drowned lanterns.

'How long has the freighter been here?' An older civilian, a government scientist holding a pair of binoculars, peered at the riddled hull of the Prospero. Below the beachhouse two sailors were loading the last of Christine's stores into the inflatable. 'It looks as if it's been stranded there for years.'

'Six months,' Christine told him. She sat beside Johnson, smiling at him encouragingly. 'When Captain Johnson realised what was going on he asked me to call you.'

'Only six? That must be roughly the lifecycle of these new species. Their cellular clocks seem to have stopped instead of reproducing, they forcefeed their own tissues, like those giant fruit that contain no seeds. The life of the individual becomes the entire life of the species.' He gestured towards the impassive Johnson. 'That probably explains our friend's altered time sense great blocks of memory were coalescing in his mind, so that a ball thrown into the air would never appear to land...'

A tide of dead fish floated past the cutter's bow, the gleaming bodies like discarded costume jewellery.

'You weren't contaminated in any way?' the lieutenant asked Christine. 'I'm thinking of the baby.'

'No, I didn't eat any of the fruit,' Christine said firmly. 'I've been here only twice, for a few hours.'

'Good. Of course, the medical people will do all the tests.'

'And the island?'

'We've been ordered to torch the whole place. The demolition charges are timed to go off in just under two hours, but we'll be well out of range. It's a pity, in a way.'

'The birds are still here,' Christine said, aware of Johnson staring at the trees.

'Luckily, you've trapped them all.' The scientist offered her the binoculars. 'Those organic wastes are hazardous things God knows what might happen if human beings were exposed to longterm contact. All sorts of sinister alterations to the nervous system people might be happy to stare at a stone all day.'

Johnson listened to them talking, glad to feel Christine's hand in his own. She was watching him with a quiet smile, aware that they shared the conspiracy. She would try to save the child, the last fragment of the experiment, and he knew that if it survived it would face a fierce challenge from those who feared it might replace them.

But the birds endured. His head had cleared, and he remembered the visions that had given him a brief glimpse of another, more advanced world. High above the collapsed canopy of the forest he could see the traps he had set, and the great crimson birds sitting on their wings. At least they could carry the dream forward.

Ten minutes later, when the inflatable had been winched onto the deck, the cutter set off through the inlet. As it passed the western headland the lieutenant helped Christine towards the cabin. Johnson followed them, then pushed aside the government scientist and leapt from the rail, diving cleanly into the water. He struck out for the shore a hundred feet away, knowing that he was strong enough to climb the trees and release the birds, with luck a mating pair who would take him with them in their escape from time.

1990.

A Guide to Virtual Death For reasons amply documented elsewhere, intelligent life on earth became extinct in the closing hours of the 20th Century. Among the clues left to us, the following schedule of a day's television programmes transmitted to an unnamed city in the northern hemisphere on December 23, 1999, offers its own intriguing insight into the origins of the disaster.

6.00 am PornoDisco. Wake yourself up with hisandher hardcore sex images played to a disco beat.

7.00 Weather Report. Today's expected microclimates in the city's hotel atriums, shopping malls and office complexes. Hilton International promises an afternoon snowshower as a Christmas appetiser.

7.15 News Roundup. What our newsmakers have planned for you. Maybe a small war, a synthetic earthquake or a faminezone! charity tiein.

7.45 Breakfast Time. Gourmet meals to watch as you eat your diet cellulose.

8.30 Commuter Special. The rushhour gameshow. How many bottoms can you pinch, how many faces can you slap?

9.30 The Travel Show. Visit the world's greatest airports and under ground car parks.

10.30 Homemakers of Yesterday. Nostalgic scenes of oldfashioned housework. No.7 The Vacuum Cleaner.

11.00 Office War. Longrunning serial of office gangwars.

12.00 Newsflash. The networks promise either a new serial killer or a deadly food toxin.

1.00 pm Live from Parliament. No .12 The Alcoholic MP.

1.30 The NosePickers. Hygiene programme for the kiddies.

2.00 Caress Me. Softporn for the siesta hour.

2.30 Your Favourite Commericials. Popular demand reruns of golden oldie TV ads.

3.00 Housewives' Choice. Rape, and how to psychologically prepare yourself.

4.00 Countdown. Game show in which contestants count backwards from one million.

5.00 Newsflash. Either an airliner crash or a bank collapse. Viewers express preference.

6.00 Today's Special. Virtual Reality TV presents 'The Kennedy Assassination.' The Virtual Reality headset takes you to Dallas, Texas, on November 22, 1963. First you fire the assassin's rifle from the Book Depository window, and then you sit between Jackie and JFK in the Presidential limo as the bullet strikes. For premium subscribers only feel the Presidential brain tissue spatter your face OR wipe Jackie's tears onto your handkerchief.

8.00 Dinner Time. More gourmet dishes to view with your evening dietcellulose.

9.00 Science Now. Is there life after death? Microelectrodes pick up ultrafaint impulses from longdead brains. Relatives question the departed.

10.00 CrimeWatch. Will it be your home that is broken into tonight by the TV Crime Gang?

11.00 Today's Special. TeleOrgasm. Virtual Reality TV takes you to an orgy. Have sex with the world's greatest moviestars. Tonight: Marilyn Monroe and Madonna OR Warren Beatty and Tom Cruise. For premium subscribers only experience transexualism, paedophiia, terminal syphilis, gangrape, and bestiality (choice: German Shepherd or Golden Retriever).

1.00 am Newsflash. Tonight's surprise aircrash.

2.00 The Religious Hour. Imagine being dead. Priests and neuroscientists construct a lifelike mockup of your death.

3.00 NightHunter. Will the TV Rapist come through your bedroom window?

4.15 Sex for Insomniacs. Soft porn to rock you to sleep.

5.00 The Charity Hour. Game show in which ThirdWorld contestants beg for money.

1992.

The Message from Mars The successful conclusion of NASA's Mars mission in 2008, signalled by the safe touchdown of the Zeus IV space vehicle at Edwards Air Force Base in California, marked an immense triumph for the agency. During the 1990s, after the failure of the Shuttle project, NASA's entire future was in jeopardy. The American public's lack of interest in the space programme, coupled with unsettling political events in the former Soviet bloc, led Congress to cut back its funding of astronautics. Successive US Presidents were distracted by the task of balancing the national budget, and their scientific advisers had long insisted that the exploration of the solar system could be achieved far more economically by unmanned vehicles.

But NASA's directors had always known that the scientific exploration of space was a small part of the agency's claim to existence. Manned flights alone could touch the public imagination and guarantee the huge funds needed to achieve them. The triumph of the Apollo landing on the moon in 1969 had shown that the road to the spiritual heart of America could be paved with dollar bills, but by the year 2000 that road seemed permanently closed. Struggling to keep the agency alive, the NASA chiefs found themselves reduced to the satellite mapping of midwestern drought areas, and were faced with the prospect of being absorbed into the Department of Agriculture.

However, at the last hour the agency was saved, and given the funds to embark on its greatest mission. The announcement in Peking on January 1, 2001, that a Chinese spacecraft had landed on the moon sent an uneasy tremor through the American nation. True, the Stars and Stripes had been planted on the moon more than thirty years earlier, but that event lay in a past millennium. Was the next millennium to be dominated by the peoples on the Asian side of the Pacific rim, spending their huge trade surpluses on spectacular projects that would seize the planet's imagination for the next century?

As the pictures of the Chinese astronauts, posing beside their pagodashaped space vehicle, The Temple of Lightness, were relayed to the world's TV screens, news came that an Indonesian space crew and an unmanned Korean probe would soon land next to the Chinese.

Galvanised by all this, a no longer somnolent President Quayle addressed both houses of Congress. Within weeks NASA was assigned a multibilliondollar emergency fund and ordered to launch a crash programme that would leapfrog the moon and land an American on Mars before the end of the decade.

NASA, as always, rose bravely to the challenge of the taxdollar. Armies of elderly spaceengineers were recruited from their Florida retirement homes. Fifty civilian and military test pilots were pressed into astronaut training. Within two years Zeus I, the unmanned prototype of the vast space vehicles that would later carry a fiveman crew, had roared away from Cape Canaveral on a sixmonth reconnaissance voyage. It circled the Red Planet a dozen times and surveyed the likely landing zone, before returning successfully to Earth.

After two more unmanned flights, in 2005 and 2006, Zeus IV set off in November, 2007, guaranteeing President Quayle's thirdterm electoral landslide, which the five astronauts saluted from the flightdeck of the spacecraft. By now the Chinese, Indonesian and Korean lunar programmes had been forgotten. The world's eyes were fixed on the Zeus IV, and its five crewmembers were soon more famous than any Hollywood superstar.

Wisely, NASA had selected an international crew, led by Colonel Dean Irwin of the USAF. Captain Clifford Homer and Commander John Merritt were former US Army and Navy test pilots, but the team was completed by a Russian doctor, Colonel Valentina Tsarev, and a Japanese computer specialist, Professor Hiroshi Kawahito.

During the twomonth voyage to Mars the quirks and personalities of the five astronauts became as familiar as any face across a breakfast table. The Zeus IV was the largest spacecraft ever launched, and had the dimensions of a nuclear submarine. Its wide control rooms and observation decks, its crew facilities and nondenominational chapel (if a marriage was arranged, Colonel Irwin was authorized to conduct it) happily reminded TV viewers of the Starship Enterprise in the Star Trek TV series, still endlessly broadcast on a hundred networks. Everyone responded to the calm and dignified presence of Colonel Irwin, the deadpan humour of Captain Homer, the chirpy computerspeak of the mercurial Japanese, and the mothering but sometimes flirtatious eye of Dr Valentina. Millions of viewers rallied to their aid when the Zeus IV passed through an unexpected meteor storm, but the ultrahard carbon fibre and ceramic hull, a byproduct of the most advanced tank armour, proved even more resilient than the designers had hoped. The inspection spacewalks seemed like gracefully choreographed ballets which of course they were, like every other activity shown to the TV audience and confirmed that mankind had at last entered the second Space Age.

Two months to the day after leaving Cape Canaveral, the Zeus IV landed on Mars, whose sombre presence had loomed ever more threateningly for the previous weeks. Signals blackouts caused by the planet's magnetic field added their own thrills and panics, skilfully orchestrated by NASA's PR specialists. But the landing was a triumph, celebrated by the hoisting of the Stars and Stripes and, behind it, the flag of the United Nations.

Within an hour the crew of the Zeus IV was standing on Martian soil beside the spacecraft, intoning their carefully rehearsed 'Hymn to the Space Age'. From that moment no Congressman dared to deny the NASA chiefs anything they demanded.

For the next six weeks public interest in the Mars mission remained high, sustained by NASA's careful attention to the emotional needs of the worldwide audience. Life within the spacecraft was presented as a cross between a TV sitcom and a classroom course in elementary astronautics. The crew tolerantly went along with these charades. Dr Valentina was seen replacing a filling in Commander Merritt's mouth, and Professor Kawahito, the heartthrob of a billion Asian viewers, won a hardfought chess tournament against the Zeus IV's combined onboard computers. Romance was in the air as Dr Valentina's cabin door remained tantalizingly ajar. The TV cameras followed the crew as they drove in their excursion vehicles across the fossil Martian seas, collecting rock samples and analysing the local atmosphere.

At the halfway stage of their mission the crew revealed a mild impatience with the media roles imposed on them, which the NASA psychologists attributed to a greater maturity brought on by a sense of planetary awe. To remind them of Earth, the astronauts were urged to watch episodes of Dallas, Dynasty and The Flintstones, and to take part in a series of Oval Office interviews with President Quayle. But their spirits lifted as the day of departure drew near. When the Zeus IV rose at last from the Martian surface the entire crew burst spontaneously into an unscripted cheer, in which some observers detected a small note of irony.

Ignoring this impromptu levity, NASA planned a lavish reception at Edwards Air Force Base, where the Zeus IV would land. Every Congressman and Governor in the United States would be present, along with President Quayle, the heads of state of thirty countries and a host of entertainment celebrities. An unending programme of media appearances awaited the astronauts there would be triumphal parades through a dozen major cities, followed by a worldwide tour lasting a full six months. NASA had already appointed firms of literary agents and public relations experts to look after the commercial interests of the astronauts. There were sports sponsorships, book contracts and highly paid consultancies. The news of these deals was transmitted to the homecoming crew, who seemed gratified by the interest in their achievement, unaware that whenever they appeared on screen their images were accompanied by the cash totals now committed to them. Two days before the Zeus IV landed, NASA announced that three major Hollywood studios would collaborate on the most expensive film of all time, in which the astronauts would play themselves in a faithful recreation of the Martian voyage.

So, at 3.35 pm on April 29, 2008, the Zeus IV appeared in the California sky. Accompanied by six chase planes, the spacecraft swept down to a perfect landing, guided by its onboard computers to within 50 metres of President Quayle's reception podium. The stunned silence was broken by an immense cheer when two of the astronauts were glimpsed in the observation windows. The crowd surged forward, waiting for the hatches to open as soon as the landing checks were over.

Despite the warmth of this welcome, the astronauts were surprisingly reluctant to emerge from their craft. The decontamination teams were poised by the airlocks, ready to board the spaceship and evacuate its atmosphere for laboratory analysis. But the crew had overridden the computerized sequences and made no reply over the radio link to the urgent queries of the ground controllers. They had switched off the television cameras inside the craft, but could be seen through the observation windows, apparently tidying their cabins and changing into overalls. Dr Valentina was spotted in the galley, apparently sterilizing her surgical instruments. A rumour swept the review stands, where President Quayle, the Congress and invited heads of state sweltered in the sun, that one of the crew had been injured on reentry, but it soon transpired that Dr Valentina was merely making soup. Even more strangely, Professor Kawahito was seen setting out six parallel chessboards, as if preparing for another tournament.

At this point, an hour after their arrival, the crew became irritated by the grimacing faces pressed against the observation windows, and the interior shutters abruptly closed. This dismissive gesture made the crowd even more restive, and the ground staff tried to force the main hatch. When they failed, the head of NASA's crash recovery team began to pound on the locks with a baseball bat borrowed from a youngster seated on his father's shoulders. The first whistles and jeers rose from the crowd, who jostled the scaffolding towers on which the impatient TV crews were waiting. A cameraman lost his footing and fell through the roof of a parked bus. Loudspeakers blared meaninglessly across the million or more spectators sitting on their cars around the perimeter of the airfield. The heads of state, diplomats and generals consulted their watches, while President Quayle, making involuntary putting movements with the portable microphone in his hands, beckoned in an unsettling way to his military aide carrying the briefcase of nuclear launch codes. The boos of the crowd were only drowned when a squadron of jet planes flew low over the field, releasing streams of red, white and blue smoke. Ordered away by the frantic control tower, the victory flight broke up in confusion as the pilots returned to their muster points in the sky, leaving a delirium of crazed smoke over the Zeus IV.

At last calm was restored when a company of military police took up positions around the spacecraft, forcing the crowds behind the VIP stands. Led by President Quayle, the dignitaries shuffled from their seats and hurried along the lines of red carpet to the refreshment tents. The TV cameras trained their lenses on the Zeus IV, watching for the smallest sign of movement.

As evening fell, the spectators beyond the airfield perimeter began to disperse. Powerful arclights bathed the spacecraft, and during the night a fresh attempt was made to contact the crew. But the messages in morse code tapped on the hull, like the laser beams shone at the darkened observation windows, failed to draw any response. No sound could be heard from the interior of the craft, as if the crew had settled in for the night, and a hundred theories began to circulate among the NASA chiefs and the teams of doctors and psychiatrists summoned to their aid.

Were the astronauts in the last stages of a fatal contagious disease? Had their brains been invaded by an alien parasite? Were they too emotionally exhausted by their voyage to face the reception awaiting them, or gripped by so strong a sense of humility that they longed only for silence and anonymity? Had an unexpected consequence of time dilation returned them psychologically hours or days after their physical arrival? Had they, perhaps, died in a spiritual sense, or were they, for inexplicable reasons of their own, staging a mutiny?

Surrounded by the deserted stands and the silent bunting, the NASA chiefs made their decision. An hour before dawn two thermal lances played their fiery hoses against the heatresistant plates of the spacecraft. But the carbonceramic hull of the Zeus IV had been forged in temperatures far beyond those of a thermal lance.

A controlled explosion was the only solution, despite the danger to the crew within. But as the demolition squad placed their charges against the ventral hatchway, the shutter of an observation window opened for the first time. Captured on film, the faces of Colonel Irwin and Commander Merritt looked down at the limpet mines, the detonators and fuse wire. They gazed calmly at the NASA officials and engineers gesticulating at them, and shook their heads, rejecting the world with a brief wave before closing the shutter for the last time.

Needless to say, NASA allowed nothing of this to leak to the public at large, and claimed that the crew had alerted their ground controllers to the possible dangers of a virulent interplanetary disease. NASA spokesmen confirmed that they had ordered the crew to isolate themselves until this mystery virus could be identified and destroyed. The Zeus IV was hitched to its tractor and moved to an empty hangar on a remote corner of the airbase, safe from the TV cameras and the thousands still camped around the perimeter fence.

Here, over the next weeks and months, teams of engineers and psychologists, astrophysicists and churchmen tried to free the crew from their selfimposed prison. Right from the start, as the doors of the hangar sealed the Zeus IV from the world, it was taken for granted that the astronauts' immolation was entirely voluntary. Nonetheless, an armed guard, backed by electronic security devices, kept careful watch on the craft. Sets of aircraft scales were manoeuvred under the landing wheels, so that the weight of the Zeus IV could be measured at all times, and instantly expose any attempt at escape.

As it happened, the spaceship's weight remained constant, never fluctuating by more than the accumulated dust on its hull. In all senses the Zeus IV constituted a sealed world, immune to any pressures from within or without. A controlled explosion strong enough to split the hull would also rupture the engines and disperse the craft's nuclear fuel supply, provoking a worldwide political outcry that would doom NASA forever. There was no way of starving the crew out to deal with the possibility of the Zeus IV missing its rendezvous with Mars and stranding itself forever in deep space, a 200ton stock of food had been placed aboard, enough to last the crew for 40 years. Its air, water and human wastes were recycled, and there were enough episodes of Dallas in the videolibrary to amuse the astronauts for all eternity.

The Zeus, in fact, no longer needed the Earth, and the NASA officials accepted that only psychological means would ever persuade the crew to leave their craft. They assumed that a profound spiritual crisis had afflicted the astronauts, and that until this resolved itself the rescuers' main task was to establish a channel of communication.

So began a long series of ruses, pleas and stratagems. The puzzled entreaties of relatives, whose tearful faces were projected onto the hangar roof, the prayers of churchmen, the offer of huge cash bribes, the calls to patriotism and even the threat of imprisonment, failed to prompt a single response. After two months, when public curiosity was still at fever pitch, the NASA teams admitted to themselves that the Zeus IV crew had probably not even heard these threats and promises.

Meanwhile an impatient President Quayle, aware that he was the butt of cartoonists and TV comedians, demanded firmer action. He ordered that pop music be played at full blast against the spacecraft's hull and, further, that the huge ship be rocked violently from side to side until the crew came to their senses. This regime was tried but discontinued after two hours, partly for its sheer ludicrousness, and partly for fear of damaging the nuclear reactors.

More thoughtful opinion was aware that the crisis afflicting the Zeus crew merited careful study in its own right, if mankind were ever to live permanently in space. A prominent theologian was invited to the Edwards airbase, and surveyed the claustrophobic hangar in which the Zeus was now entombed, draped like Gulliver in its cables and acoustic sensors. He wondered why the crew had bothered to return to Earth at all, knowing what they probably faced, when they might have stayed forever on the vast and empty landscapes of Mars. By returning at all, he ventured, they were making an important point, and acknowledged that they still saw their place among the human race.

So a patient vigil began. Concealed cameras watched for any signs of internal movement and electronic gauges mapped the smallest activities of the crew. After a further three months the daily pattern of life within the Zeus IV had been well established. The crew never spoke to each other, except when carrying out the daily maintenance checks of the spacecraft systems. All took regular exercise in the gymnasium, but otherwise stayed in their own quarters. No music was played and they never listened to radio or television. For all that anyone knew, they passed the days in sleep, meditation and prayer. The temperature remained at a steady 68...F., and the only constant sound was that of the circulation of air.

After six months the NASA psychiatrists concluded that the crew of the Zeus IV had suffered a traumatic mental collapse, probably brought on by oxygen starvation, and were now in a vegetative state. Relatives protested, but public interest began to wane. Congress refused to allocate funds for further Zeus missions, and NASA reluctantly committed itself to a future of instrumented spaceflights.

A year passed, and a second. A small guard and communications crew, including a duty psychologist and a clergyman, still maintained a vigil over the Zeus. The monitors recorded the faint movements of the crew, and the patterns of daily life which they had established within a few hours of their landing. A computerized analysis of their foottreads identified each of the astronauts and revealed that they kept to their own quarters and seldom met, though all took part in the maintenance drills.

So the astronauts languished in their twilight world. A new President and the unfolding decades of peace led the public to forget about the Zeus IV, and its crew, if remembered at all, were assumed to be convalescing at a secret institution. In 2016, eight years after their return, there was a flurry of activity when a deranged security officer lit a large fire under the spacecraft, in an attempt to smoke out the crew. Four years later a Hollywood telepathist claimed to be in contact with the astronauts, reporting that they had met God on Mars and had been sworn to silence about the tragic future in store for the human race.

In 2025 the NASA headquarters in Houston were alerted to a small but sudden fall in the overall weight of the Zeus 170 pounds had been wiped from the scales. Was the spacecraft preparing for takeoff, perhaps employing an antigravity device which the crew had been constructing in the seventeen years since their return? However, the treadpattern analysis confirmed that only four astronauts were now aboard the craft. Colonel Irwin was missing, and an exhaustive hunt began of the Edwards airbase. But the organic sediments in the trapped gases released from a discharge vent revealed what some engineers had already suspected. Colonel Irwin had died at the age of 62, and his remains had been vapourized and returned to the atmosphere. Four years later he was followed by the Japanese, Professor Kawahito, and the Zeus was lighter by a further 132 pounds. The food stocks aboard the Zeus would now last well beyond the deaths of the three astronauts still alive.

In 2035 NASA was dissolved, and its functions assigned to the immensely wealthy universities which ran their own scientific space programmes. The Zeus IV was offered to the Smithsonian Institute in Washington, but the director declined, on the grounds that the museum could not accept exhibits that contained living organisms. The USAF had long wished to close the Edwards airbase, and responsibility for this huge desert expanse passed to the National Parks Bureau, which was eager to oversee one of the few areas of California not yet covered with tract housing. The armed guards around the Zeus IV had long gone, and two field officers supervised the elderly instruments that still kept watch over the spacecraft.

Captain Homer died in 2040, but the event was not noticed until the following year when a bored repairman catalogued the accumulated acoustic tapes and ran a computer analysis of treadpatterns and overall weight.

The news of this death, mentioned only in the National Parks Bureau's annual report, came to the attention of a Las Vegas entrepreneur who had opened the former Nevada atomic proving grounds to the tourist trade, mounting simulated Abomb explosions. He leased the Zeus hangar from the Parks Bureau, and small parties of tourists trooped around the spacecraft, watching bemused as the rare treadpatterns crossed the sonar screens in the monitor room.

After three years of poor attendances the tours were discontinued, but a decade later a Tijuana circus proprietor subleased the site for his winter season. He demolished the now derelict hangar and constructed an inflatable astrodome with a huge arena floor. Heliumfilled latex 'spacecraft' circled the Zeus IV, and the performance ended with a mass ascent of the huge vehicle by a team of topless women acrobats.

When the dome was removed the Zeus IV sat under the stars, attached to a small shack where a single technician of the Parks Bureau kept a desultory watch on the computer screens for an hour each day. The spaceship was now covered with graffiti and obscene slogans, and the initials of thousands of longvanished tourists. With its undercarriage embedded in the desert sand, it resembled a steam locomotive of the 19th century, which many passersby assumed it to be.

Tramps and hippies sheltered under its fins, and at one time the craft was incorporated into a small shanty village. In later years a desert preacher attracted a modest following, claiming that the Messiah had made his second coming and was trapped inside the Zeus. Another cultist claimed that the devil had taken up residence in the ancient structure. The tract housing drew ever closer, and eventually surrounded the Zeus, which briefly served as an illuminated landmark advertising an unsuccessful fastfood franchise.

In 2070, sixtytwo years after its return from Mars, a young graduate student at Reno University erected a steel frame around the Zeus and attached a set of highintensity magnetic probes to its hull. The computerized imaging equipment later confiscated by the US Government revealed the silent and eerie interior of the spacecraft, its empty flight decks and corridors.

An aged couple, Commander John Merritt and Dr Valentina Tsarev, now in their late eighties, sat in their small cabins, hands folded on their laps. There were no books or ornaments beside their simple beds. Despite their extreme age they were clearly alert, tidy and reasonably well nourished. Most mysteriously, across their eyes moved the continuous play of a keen and amused intelligence.