The colonel was looking agitated. “Mister Fish, this is not-ta time for talk. The danger is extreme. We recognize at least seven wanted criminals in the club. It is amazing good fortune for us. But they will kill you without a thought and shoot their way out. Until the
squadra
arrives I have only three people here and we cannot return fire in a public place.”
“What then?”
“Hide! Back on stage!”
“Beckenham, I want you to open up the Planetological Institute in the Via Galileo and I want a car standing by to take me there.”
“Don’t be a bloody fool.”
The sound of whistling and clapping penetrated through the stage floor. A wooden panel opened from above and a pair of long sequined legs in red high heels emerged, climbing unsteadily down the steps.
“Go, go!” Vannucci said, pushing Webb back to the ladder.
“I want to be in Oxford in three hours maximum. I don’t care if you have to charter a Jumbo.”
Vannucci was forcing Webb up the ladder.
“And I need a fast laptop computer on board. I left mine in the safe house.”
A scared look came over Beckenham as it dawned on him that Webb was serious. Vannucci was practically lifting the astronomer upwards.
“With a Linux interface,” Webb shouted down, disappearing.
“A what inner face?”
Inside the dark box again, Webb felt himself being trundled some yards, he guessed to just off-stage. The band started up on some sleepy tune, rose to a finale.
Footsteps approached. Webb fell against the side of the box as it was tilted up. It was wheeled for maybe ten yards and then a tremendous
Crack!
erupted within it. A man shouted, angry and frightened; a woman screamed; running footsteps.
Somebody kicking hard at the base of the box. Webb, drenched in sweat, took two feet to it and it burst open. Beckenham, the policeman and a woman in a black cocktail dress dragged him out and on to his feet. All three with guns and the woman, in addition, with an evening bag. A walrus-moustached janitor in a glass booth crouched, quivering, behind a chair, eyes wide with fear. It could have been a scene from a comedy.
Webb was about to speak when the woman grabbed him violently by the hair and hauled him down on to his knees. At the same instant a bullet smacked into a whitewashed wall next to his face; Webb actually glimpsed it, spinning and buzzing, on the rebound. Then the policeman was hauling open a red emergency exit door, and an alarm bell screamed into life, and Webb was being thrust into the narrow lane outside. He fell heavily.
The woman appeared, hauled Webb to his feet and pushed him ahead of her along the lane. Webb got the message and took off like a hare. He sprinted round a corner and almost collided with the young Tuscolo killers rushing out of the Werewolf Club. Webb dived to the ground. The hard cobbles knocked the breath out of him. From behind he heard two sharp bangs, and two bright yellow flashes briefly lit up the neon-strobed lane. The young ones fell like sacks. The lane emptied, people stampeding into the club or disappearing into doorways. The Tuscolo woman’s face was a foot from Webb’s. She had long black hair, her eyes were half-closed and quite lifeless, and something like porridge was oozing from a neat black hole in the centre of her forehead; the youth was clutching a long, thin knife, but he too was lifeless. The alarm was deafening in the narrow lane.
Webb got up and swayed, on the verge of fainting. The woman, about ten yards away, was calmly putting her high-heeled shoes back on. He said, “Can we get a move on here?” but his voice came out as an inaudible whisper.
A
squadra volante
car whisked Vannucci, the woman and Webb across the city to the
Istituto di Planetologia
in four minutes. The doors were already open and a tousle-haired caretaker was engaged in an animated exchange with two
Carabinieri
, his hands waving dramatically. He unleashed a stream of Italian at Webb as the astronomer ran past, into the lighted building.
He ran up a flight of stairs and along a dark corridor towards Giovanni’s office. He had used a visitor’s password two years ago and there was no chance that it would still be valid; he would just have to rouse Giovanni at home. He tried his old username and password anyway and—joy!—it worked: the Linux window appeared.
Webb looked at his watch and, yet again, converted to the Eastern Standard time zone. He had been in the Werewolf Club for nearly an hour, and he had four hours left to identify Nemesis.
What he had to do was run the known Earth-crossers backwards in time, perturbing their orbits with the gravitational pull of the planets, and seeing how close each asteroid had been to the Earth in the Year of Our Lord 1613, on 28 November.
He took a minute to think. They would have fast orbit integrators here but he wouldn’t know their names or modes of operation. The one he used at Oxford, developed by the celestial mechanics group at Armagh Observatory in Northern
Ireland, was based on Bulirsch-Stoer and symplectic routines and probably as fast as anything on the planet.
The future orbit of an asteroid or comet can be approximated by a series of straight-line steps. Each step takes so much time to compute. The greater the length of the stride, the fewer are needed in total, and so the faster the orbit is calculated. However large strides, although fast, lead to unreliable results: no real asteroid ever moved in a series of straight lines. An orbit computed with very large steps deviates more and more from reality. A computation with very small steps is highly precise but takes a very long time. Webb’s quandary was that he needed high precision but had very little time.
A message on the terminal wished him a Merry Christmas but regretted that the Oxford Institute mainframe was down for maintenance over the festive season.
He had no access to the Armagh computers.
He dialled in to the Observatory’s home page for the telephone number and called through. Paolo, luckily, had been prevented by poverty from joining his family in Turin this Christmas, and as usual he was working late. The Italian student immediately arranged to put the programmes on to anonymous ftp, which would allow anyone to gain access to them. Webb had them into Giovanni’s machine in minutes and then transferred them on to half a dozen floppy disks, along with the planetary ephemerides for the past four hundred years, and the orbital elements of all known near-Earth asteroids.
He now had what he needed. Everything but time.
He typed in a brief e-mail message to Eagle Peak:
The Navigator has reached the New World.
Natives friendly.
It was Enrico Fermi’s coded wartime message announcing that the atom had been split. Willy Shafer would understand it, but not a casual hacker.
He ran back out of the building to the police car, which took off, blue light flashing, through the town.
Vannucci glanced at Webb in the flickering light from the streets. “I would love to know what this is about.”
Webb stayed silent.
“A countryman of yours is brutally killed on Italian soil. I do not like that. If I had my way you would now be answering questions in
La Madama
.”
“But you’re prevented by instructions from above, right?”
The policeman lit up a Camel cigarette. “Your little book. Was it worth it?”
Webb thought of Leclerc hurtling to his death, and Walkinshaw riddled with bullets, and the young ones with holes through their brains. He nodded. “Definitely. Was anyone hurt in the club?”
“You mean apart from the people who died in front of your eyes? One of my men is in the San Salvadore, undergoing emergency surgery.”
“The people who died were the ones who killed Walkinshaw. The older man with me in the club set it up. They were after the book. That’s all I can tell you. A grilling in the
questura
would yield no more.”
Vannucci took a reflective puff at his cigarette. “I would not be so sure of that.”
“Your lady—what a brilliant shot.” She looked back at Webb from the front passenger seat and gave a cool smile. Her English was good: “Given the poor light, I thought I did well.”
This one won’t need counselling, Webb thought. He looked out at the scenery speeding past and suddenly felt cold. “This isn’t the way to the airport.”
“We’re taking you to the military airfield at Ciampino.”
They reached it in ten minutes. The police car drove straight on to the runway. An executive jet was waiting, door open, headlights on, engines whining, Beckenham at the steps with laptop computer in hand. Webb grabbed the little
computer from Beckenham, shook hands briefly, and then the door was closed and the aircraft accelerated swiftly forwards.
As the jet curved into the sky, Webb glanced down at Rome by night, a great luminous spider’s web divided by the Tiber. But there was no time for the luxury of terror. He fed in the programmes from the floppy disks.
Beckenham had done well at short notice. It was a fast little machine; it might take say ten minutes to explore the past history of each Earth-crosser back to 1613. There were five hundred known Earth-crossers. So, the identification process could take up to eighty-five hours. Three and a half days, day and night.
He had three and a half hours.
A supercomputer would do the job in minutes. He could have tried to download the Armagh programmes across to the Rutherford-Appleton HPC if he had had access, but he hadn’t. It might take days to get into the supercomputer from the outside, and they probably had batch jobs booked up for days after that. He could attempt to muscle in now by wielding the AR or the Chairman of Council, but that could attract attention, and that attention could lead to a nuclear attack.
He could e-mail the information through to Kowalski. But there were no encryption arrangements between Eagle Peak and either Oxford or the aircraft. An e-mail message could circle the globe and touch down in half a dozen states before it reached its destination. Too dangerous: he might as well use a loudhailer.
And if the traitor on the team—if there was a traitor on the team—got to the message first, there was no telling what mischief might be done.
Having exhausted every alternative, Webb turned to the little toy on his lap.
The trick, as he saw it, was to go for the candidates most easily diverted. Leclerc would have fed in knowledge of past Russian probes and given him a more targeted list. Still, he could use the standard list of potential hazards, starting with
Apophis, Nereus and other obvious choices. With luck, Nemesis would be on the list of known potential hazards and he would have it within a few hours. That was the theory.
He clicked on an icon, and the machine asked him a few questions. Are you integrating the orbit forward or back in time? How long would you like the integration to go? What positional accuracy (in AU) would you like on the termination date (the more accurate the required position, the slower the integration)?
The preliminaries over, the machine got down to specific orbits. First it asked him for the semi-major axis of the orbit; then its eccentricity; and then the three angles defining the orientation of the orbit in space: inclination, longitude of ascending node, longitude of perihelion. The orbit’s size, shape and orientation in space defined, it finally requested one last number: the true anomaly, a precise date at which the asteroid was at its point of closest approach to the sun (Julian date, please).
There was care to be exercised. In 1582 Pope Gregory XIII, on the advice of his Jesuit astronomer Clavius, had taken ten days out of the Christian calendar which had, over the centuries, gradually drifted out of phase with the seasons. The Catholic nations had taken this up at once. By the time the English had reluctantly joined up in 1752, eleven days had had to be taken out of the Protestant calendar and the peasantry had duly rioted, being reluctant to pay double rent. Vincenzo’s observation, having been made in seventeenth-century Italy, was therefore 28 November by the Gregorian calendar. But Webb then had to convert this to the Julian date, a steadily ticking clock used by astronomers to bypass the vagaries of peasants and politics. This is reckoned from 1 January 4713 BC. Julian days start at noon. A Julian day is therefore shifted by twelve hours relative to the civil day and twelve hours at twenty-five kilometres a second is the difference between a million-kilometre miss and a hit.
He dug into the
Astronomical Ephemeris
and converted
Vincenzo’s Catholic date to the appropriate Julian Day. From then on, Webb hoped, it would be plain sailing.
He started with Nereus.
Two little spots on the screen, one yellow and one blue, began to whirl rapidly around a fixed central disc, eventually coming to an abrupt halt with 28.11.1613 (Greg.) showing in the top right-hand corner of the screen. The process had taken about twenty minutes. The spots were nowhere near each other. On to the second asteroid on the easy-to-shift list. And then the third.
Over the English Channel, as the little jet sank along its approach path, and Webb punched in a succession of increasingly implausible candidates, it began to look as if Nemesis was not amongst the known Earth-crossers. At the moment the wheels made screaming contact with the runway he scored off the last candidate in his list of possibles. None of them had fitted Vincenzo’s observation. Either good men had died chasing a phantom, or Nemesis was an asteroid known only to the Russians.
Webb settled into the back of a ministerial Jaguar and started on the Mission Impossibles, the asteroids which could not realistically be shifted in orbit. The car sped him along the M25 at a hundred miles an hour; either the driver was taking a chance or the police had been asked to turn a blind eye.
There was nothing else to be done. They were impossible because they were too fast to shift, but deadly—because of their speed—if somehow diverted nevertheless. He made the identification just as the car turned off on to the M40. He ran the program again, pushing the accuracy as far as he dared. The program now took thirty agonizing minutes to complete, but the result was identical, and suddenly the multiple insanities which had dominated his life these past few days—the Inquisition, the mad bee-keeper, the crazy old fascist lady, the greedy assassin and his weird and wicked companions—all were sloughed out of his mind and
dumped in the dustbin of history.
I’ve beaten the lot
, he thought triumphantly. He picked up the carphone, tingling with excitement, and dialled through to the Astronomer Royal’s ex-directory home number.