CHAPTER 20 MARCH/APRIL                                              ‘Welcome to `The Undertakers'.’ Silvester patted Allan on the back. He had a pony tail and moccasins.          ‘Why `Undertakers'?’          ‘'Cos were putting OS65 to rest. Company trying to phase it out see. Unglamorous eh? You mind that?’          ‘Not a bit.’          ‘Good. Most of our boys been taken over to OS_LAB, the Great White Hope. They say it's way behind schedule and full of bugs. Anyway. '65's still got a few beauties of its own and we still gotta fix 'em. Here's the file of registered bugs. You take this one. See the date reported is here. You got printouts, Problem reports. See here? See what you can do. Fill in the fix report here. Bring it back to me n' I'll show you what we do next.’          *      *      *      *      *          The library was good. Not just on computers. Maps of the mountains. He took photocopies. Guidebooks. Not many. The guidebooks said the maps were bad - drawn straight from aerial photographs without ground triangulation. All warped. But better than nothing.          *      *      *      *      *          ‘Have you been to the mountains?’ he asked them.          ‘Been to El Paso,’ they said.          ‘What's it like?’          ‘Dude ranch. It belongs to the company. They show you how to saddle a horse or throw a lariat.’          ‘How often do you go?’ he asked.          ‘Been there last year sometime,’ said one.          ‘Me too. Year before. It's OK. Might go again,’ said another.          ‘Ever been anywhere else in the mountains?’          Headshakes, shoulder shrugs.          ‘Do you know of anyone in Springs goes to the mountains?’          More headshakes.          *      *      *      *      *          Friday night. Alone. He camped near a village and watched a blood red sunset.          Saturday morning. A crowd of inquisitive urchins watched his every move. They watched him open-mouthed as he cooked. They peeked into his tent as he slept. They giggled uncontrollably as he ate and, most embarrassing of all, made it almost impossible for him to pee or shit. Take note - keep away from villages.          The mountains were like no others he knew. No vegetation. Dust dry and appallingly hot. Take note - plan routes for maximum shade.          The height he could reach was governed by how much water he could carry from the small river in the bottom of the valley. Note - get more water bottles.          Sunday evening back to `Springs'.          *      *      *      *      *          ‘Alone in the mountains! You not lonely?’          ‘No. Never.’          Never when he was alone. Only when he was surrounded by people with whom he had little in common.          ‘Why don't you drop round to the Flamingo bar this evening? They make the best Manhattans outside Big Apple.’          ‘Tried the Aconcagua Club? - play the wheels or shoot crap.’          ‘What's your handicap? We're looking for someone make up a foursome.’          ‘Have you tried the games room? It's in Elvira. First floor.’          Curious, he wandered round to the games room that evening. Jake was there with full helmet, gauntlets and boots clawing away at empty space before him. Jake offered him a turn with the equipment and to his amazement Allan found that when he put the helmet on he was confronted by a rock face. With the gloves on he could move two virtual hands on to virtual holds on the virtual rock and, with his bottom supported by a stool, he could place his virtual booted feet on to virtual footholds and climb the virtual cliff. The real magnificent thing was just twenty miles away.          He hung the picture of the Arisaig sands on his bedroom wall.          *      *      *      *      *          His driving was improving. He lacked experience with city traffic but he could handle the truck well on the open road and that was just as well because the open road was hairy at times especially in the mountains. On the narrow unmetalled single-track roads an encounter with another vehicle was an event of some consequence which often involved both drivers getting out, passing the time of day, offering cigarettes and negotiating terms to allow one another to pass.          According to the map the village of Casserone was at the end of the road but he had found that a passable track continued up the valley and he had formed a plan. Some of the outlying ranches were served by a bus-service or more correctly a truck-service. He calculated that if he left his Dodge at the farthest ranch he would be able to cross the mountains to the North into the next valley and then by truck-service return to get his wheels back. Even if that was not possible the farthest ranch was near high steep mountains and would be a good base for a bit of exploration.          There was one snag.          He had forgotten his Spanish-English dictionary so as he drove leaving a comet trail of dust and stour, the wheel leaping and jerking in his hands, he ran his tongue over the questions he would ask. What was the word for bus/truck again - Camino - that was it. Esta camino passa aqui? - Does a truck pass here? It was later, when he got back to Ocean Springs and to the life support system of the dictionary he learned the difference between camion (a lorry) and camino (a roadway). That explained a lot.          *      *      *      *      *          Theresa made her way towards the orange grove picking up sticks as she went. The bundle in her arms was already quite heavy. The orange grove was surrounded by a fringe of bushes and these were a good source for sticks. She stopped to pick up another and then realised that with its shape and thickness she could, with a piece of rag, make a good doll with it. Carefully she placed it on a stone, to be retrieved later. Her mother, practical as ever, would simply see it as good kindling. As she straightened her eye caught an unusual flash of bright yellow in the bushes ahead. A yellow dress? It was too large for a dress and as she approached she saw that it was a vehicle. It was parked beside her father's orange grove. She saw a movement in the bushes and stopped. Theresa was a brave girl. At ten years old she could do a full day's work at weekends and in the evenings after school was a genuine help to her mother with the baking and sweeping and, as now, gathering kindling. Her father worked desperately hard for the orange grove and she would defend it to the death. She crept forwards on her bare brown feet.          A tall lean man was bending beside the yellow truck fumbling with a bundle of orange fabric. He was pale coloured - a Gringo. Her father said that all Gringos were mad. Theresa put down her bundle of sticks so that she could run away more easily. She crouched down behind a bush and watched. The man stretched the orange coloured fabric out on the brown earth and pushed some long bendy rods into it. He opened a small satchet of the same type of fabric and poured its contents on to the ground. Pieces of metal, sharp spikes which glittered like silver fish, poured on to the ground. He picked some of these up and went round the perimeter of the big bundle pushing the spikes into the soil and sometimes driving them deep with the sole of his big boots. Then grasping the bundle in the centre he lifted and the whole thing rose up and became like a big beehive with a hole in the side. Again the man went round the perimeter poking the end of the rods into the soil and then he bent down and crawled into the beehive. Theresa was amazed and in her amazement she came round the side of the bush to see better. At that moment the man put his head out of the beehive and saw her standing there with her bare feet, print dress and little apron, with her mouth open.          ‘Er - Hello,’ said the man. He spoke in a funny way, mispronouncing the vowels and slurring words.          Theresa said nothing. She just stared, and then she turned and ran back round behind the bush.          The man crawled out of the beehive and stood up. He went over to the yellow truck and reached inside and then he was walking towards her. His hand was offering her a bar of chocolate. She recognised the colour of the wrapping from the big posters at the side of the road she had seen down at Casserone. She had never tasted chocolate but one of her friends at school had. Her hand went to her mouth. The man was close. She stretched out her hand and took the chocolate.          ‘Good night,’ said the man. ‘Er .. good day. Hello. Thank you.’          Theresa still said nothing.          The man stretched out his hand, took the bar of chocolate from her, broke it into pieces and offered her back the bundle of broken pieces. He made signs for her to put a piece in her mouth. She tried a piece. It was smooth and sweet. Now she could tell Maria a thing or two.          ‘Please,’ said the man and pointed over towards the dusty jeep-track. He walked towards it and beckoned her. They stood facing one another on the road, Theresa'a mouth was jammed with chocolate.          The man pointed at the road way at their feet.          ‘A roadway pass here?’          His voice and his eyebrows lifted indicating a question. Theresa's brows knitted. She struggled to understand and then nodded slowly.          ‘Claro,’ she said showing a mouthful of masticated chocolate.          The man pointed at the road again.          ‘And the roadway pass here tomorrow TO Casserone?’          Theresa'a eyes opened like saucers.          ‘Claro.’          ‘And the roadway pass here tomorrow FROM Casserone?’          Her father was right. The Gringo was mad. She took a step back, nodding her head to placate him.          ‘And the roadway pass here next week?’          She turned and ran.                   Later she returned with her father. She had a little bundle of oranges wrapped up in her apron and the strange man took a photograph of her sitting beside her gift.          Theresa's father, Hironimo Arostica, was small with a dark Indian face which wrinkled easily into a smile to show a row of broken discoloured teeth. His hands were hard and calloused with labour but his heart was soft and generous. He invite Allan to have a meal. Theresa and her mother served at table while the men ate. Allan was self conscious about that, but knew it was the fashion and would have made them uncomfortable to break the tradition. Theresa was allowed to stand at her father's side and he put an arm round her as he talked with Allan. Talk was not quite the right word. They conversed but body language played a major part in the conversation. Allan built a little relief map of the area in the dust outside the door of the ranch and explained his intentions. He drew roadways on the map and made the noise of a truck as he traced the route. Hironimo nodded in agreement but was horrified and showed with his hands how steep the mountains were. Allan pulled some photographs out of his document bag and showed Hironimo pictures of himself climbing crags and also on the West Face of the Dru in the Alps. After supper they all came to watch him as he demonstrated on a small crag near the house. Hironimo shook his head and patted Allan on the back. He had seen everything now.          *      *      *      *      *          ‘You got plans for Togetherness Day?’ Mrs Tomasco leaned over and put another waffle on his plate.          Allan said, ‘Togetherness Day?’          ‘Willie not tell you?’ she looked across the table at Willie in mock exasperation. Willie swallowed a mouthful and dabbed his lips with the napkin he had tucked under his chin.          ‘We got lots of specials here,’ he said. ‘The guys in personnel think its good for morale. We borrow all the Chilean National Days and invent a few more. This Monday coming is `Togetherness Day'. Whole day off. Parades. Speeches. You know the kind'a thing.’          Sarah, Willie's six-year-old, said, ‘I'm in the parade.’          Willie said, ‘I think Allan's a bit of a loner. Parades are not quite your thing are they?’          Allan nodded, smiling.          ‘How are they treating you?’ Mrs Tomasco asked Allan ‘Has Willie given you something interesting to do?’          ‘Oh yes. I'm fine,’ said Allan.          ‘I was thinking,’ said Willie. ‘Has anyone said anything to you about Vesuvius?’          ‘No. Vesuvius the mountain?’          ‘Nup. Vesuvius the bug. It's got a proper number but everyone calls it Vesuvius. It doesn't erupt often but when it does you know you've been zapped.’          ‘No. No one said.’          ‘It's been around a long time and no one has been able to track it down. It would be nice to nail it down before we nail down the coffin lid on OS65. Maybe a fresh mind would see something. You could take a look.’          ‘Sure. I'd be glad to. Oh! One thing I wanted to ask you. Will you sign for me to get a micro out of stores so I can work evenings in my own room?’          ‘Sure.’          ‘Ain't you got something better to do evenings?’ said Willie's wife. ‘Young fella like you.’          *      *      *      *      *          The weekend of Togetherness Day Allan went off on his own again. He drove down to Copiapo and stayed at the Hotel San Miguel. They remembered him. Saturday he drove North East and tried the mountains there and planned an over-the-mountains trip from there to Hironimo's place.          *      *      *      *      *          The sports centre at `Springs' had every conceivable exercise machine but no climbing wall and the desert was depressingly horizontal. But the Shower Tower wasn't. Each window had its verandah which protected the window below it from the noonday sun. This gave the vertical columns of windows the appearance of a stack of shelves. Between the columns there was a recess, a foot deep and five wide running the full height. The whole building was fluted.          Allan stepped off the path and went over to the nearest recess. He could bridge the recess easily with a hand and foot on either wall. A perfect way to cat-burgle the Shower Tower. Fifteen feet up, spread-eagled, he heard someone coming along the path and quickly dropped to the ground. He tried to look nonchalant as one of the glossy Marsdon hostesses clipped past in her stilettos.          He had more opportunity to study the Gracewell Building for climbable features. The only way up would have been to climb from verandah to verandah. That would have been easy with a grappling hook and an 'etrier' or short rope ladder. Not REAL mountaineering though. More interesting would have been the descent. He reckoned could have 'dreeped' from one verandah to another, provided he set up a pendulum motion to take him inwards as he dropped from his hands at full stretch. The idea did not get any further than an idea, however. He did not think the explanation - ‘Because It's There’ - would go down very well if he had been caught at it.                   *      *      *      *      *          It was officially called ‘Fault No 25019’. and it was triggered by a curious combination of circumstances which were hard to reproduce. Several customers had complained about it. There was printout evidence. Output data would suddenly appear in the wrong window and the whole screen would lock solid. Nothing would happen no matter what keys you hammered. You had to bring the system down and re-boot, that is, start up again, to clear the fault. It was disastrous for the customers and embarrassing for MCI. Fortunately most customers were completely unaware of Vesuvius.          So rare and elusive was it that the Undertakers had more or less given up trying to pin it down, but they had ideas. Something interrupted a critical section, one of the bits of the program which should never be interrupted, at exactly the wrong moment.          ‘Ok if I work late tonight Willie?’          ‘Sure. What's the problem?’          ‘I've got an idea about Vesuvius. I'd like to try it out.’          ‘Want to explain?’          ‘No.’          Willie thought about that. ‘This is a team effort Allan. We communicate.’          ‘Indulge me Willie this once. I'll need to dump the system on to a clean machine.’          Another pause. A shrug of his fat little shoulders.          ‘Ok.’          In the lab they had several computers which were used for testing. He chose one which was not connected to the network and installed a fresh copy of the operating system on it as though he was a customer starting up for the very first time. It took a couple of hours to load all the tapes and by that time the lab was quiet. While he was at it he loaded the source code as well. The source code was the original language of the system before it was converted to machine language. The next task was to couple a microcomputer to the machine as if it was a terminal. He connected three micros.          ‘Setting up your own network?’          Gordon was standing at his shoulder.          ‘Sort of. I'm chasing Vesuvius. I'm going to generate a pattern of interrupts.’          ‘We've been through that already.’          ‘So? I'm only wasting my own time.’          Gordon patted him on the shoulder as though as one might with a senile ancient. He wandered off to the coffee machine and got himself a cup of green pea soup with milk and extra sugar. He kicked the machine.          ‘Shit! How about applying your talents to this bloody thing?’          Allan waited until Gordon had wandered back to his own desk and then slipped his floppy disc into the drive. It took about twenty minutes to load and set up the software he had prepared on his own micro - all the stuff he had developed with Rosa. This was the test of the theory. He let it rip.          *      *      *      *      *          ‘Getting anywhere?’          Allan was contemplating the buttons on the coffee machine. Gordon was back at his elbow.          Allan said, ‘I'm trying to work out how to avoid getting tomato ketchup with my hot chocolate.’                   ‘I mean with Vesuvius.’          ‘Oh. Maybe. I expect not.’          ‘Can I see?’          ‘There's nothing to see. It's just running through patterns.’ He yawned and stretched. ‘I was just hoping to eliminate some things but it will take a while. If anything turns up I'll call you.’          *      *      *      *      *          Some time between three and four in the morning he woke. He was lying on the floor with a seat cushion under his head. Gordon had gone. The message was on the screen. Two parts of the op-system were shouting at each other and neither was listening. A deadly embrace. Nailed!          Instantly awake he studied the source code printout. It was obvious when you saw it. How could it ever have worked? He drew a pink highlight pen through the lines of code.          The next step was to cover his traces. He programmed a pattern of interrupts which would throw the system repeatedly into the error condition to reproduce the fault over and over again. The screen locked solid every time. More programming created a number of alternative patterns which did not reproduce the fault but he knew Willie would demand to know how he had found the error and he needed an alibi. His story would be that it was a happy fluke. He had run the fault to earth by trying alternative patterns. By eight a.m. he had constructed the alibi program and was asleep once more on the floor when Willie found him.                   *      *      *      *      *          The following week Willie called him into his office. When one of the office juniors had left two cups of coffee on the table, Willie reached under his desk and pulled out a bottle of Glenfiddich. He waved the neck of the bottle over Allan's cup and raised his eyebrows and seemed disappointed when Allan declined. He splashed some into his own cup and sat back.          ‘You're wondering what it's about? .... Well I wanted a word with you about security.’          Allan stiffened but tried to disguise it.          ‘I'd like you to help the guys in security’          Hot with relief Allan took a sip of coffee. It was unusual to find 'security' being handled by software maintenance but some years earlier, Willie had fought a political battle and won security for himself. He had argued that it was illogical to maintain a piece of software without at the same time maintaining its level of security. Now it was his pet topic. Maintenance is patient, routine and systematic, or it should be. Security, especially the business of identifying and countering hackers, viruses and sundry other threats to the privacy and security of a uses data, requires a bit of flair, a bit of lateral thinking.          ‘Anything in particular Willie?’          ‘Yea. You see, I reckon the guys here do a good job. They're a lively bunch and they have so far managed to stay one jump ahead. When someone comes up with a new wheeze it doesn't usually take them long to track it down.’ He paused and leaned back in his seat. ‘But I would like to get ten jumps ahead.’          He was in expansive mood and beaming. He waved a finger in the air.          ‘Suppose, just suppose we could take a look into the future and work out what the bad guys were going to throw at us next year, and we got ready for them.’          Allan just nodded in what he hoped was a wise and encouraging way. Willie continued.          ‘I've been studying your CV again Allan and I reckon we're not making full use of your talents....’ he looked at Allan hard. ‘.... and I'm not convinced that the way you found that Vesuvius bug was entirely a fluke.’ He waited for a while, holding Allan's eye, and then, when Allan made no response he smiled and looked down at his cup and spoke to it. ‘So I think we should use you in a long range role.’ His eyes came up. ‘I'd like you to take a look at the mathematics of virus attacks.’          Allan made a puzzled face. ‘Can you explain?’          ‘Yea. The reason we call them viruses is because they spread like real viruses or something like them. I read an article in Scientific American last year which described the mathematics of the spread of epidemics. Real virus epidemics I mean, like flu and AIDS. I reckon that it might be a good idea to analyse our problem the same way. I would like to know how bad this virus thing could really get. What is the very worst they could throw at us. The AIDS thing caught a lot of people by surprise and it spread a long way before the danger was recognised. I wouldn't like the same thing to happen to us. The guys in security have built up a whole lot of data on viruses which you might be able to use.’          ‘Why me Willie?’          Willie swung round in his swivel chair until he was sideways on. It was the kind of question he liked to answer.          ‘I like to think I'm a good manager and a good manager plays to the strengths of his people. You're a loner Fraser. That sticks out a mile. Usually I like to integrate people into the team. They're more useful that way. But now and again you get what I call a useful loner. The Vesuvius bug business showed me that you're a useful loner. So, if you happen to have a job that's best tackled by a loner then it's sensible to put them together. In this case there is no deadline and not much harm done if you stepped under a locomotive, so a back up team is unnecessary.’          ‘Ok, Willie I'll have a go.’          Tomasco came round his desk to guide Allan out of the office. He tried to put an arm round Allan's shoulders but that would have meant that his feet would dangle clear of the ground so he just grabbed Allan's upper arm.          ‘I hear you slope off into the mountains at weekends. Don't go and break your neck will you?’          And before he closed the door he said, ‘Do you have a gun? There are bandits in the hills here - and I mean real ones.’          *      *      *      *      *          The official notice on the door said 'Software Security Section' in small neat lettering, and underneath 'Team leader : John Passold'. The unofficial notice was much larger and written in Micky Mouse lettering. It said 'Fort Apache - the fastest guns in the West'.          That was the first indication Allan had that he was entering a world of fantasy fanatics and ego-trip eccentrics. They called themselves 'The Cavalry' while the 'Bad Guys' or just 'The Enemy' came in three flavours.          The 'Bandits' did what they did for some understandable reason like fraud and they tried to keep their activities secret. Rarely was their expertise in matters computing up to their ambition.          The 'Indians' did it just for the hell of it and could not resist announcing their presence. Sometimes they deliberately destroyed the system or deleted data, sometimes the destruction was accidental and nearly always they left behind messages like 'You have just been Zapped by The Great Mafisto'. Indians were usually very expert indeed and the Cavalry had a kind of respect for the very best. In fact the more he saw of the Cavalry the more Allan became convinced that they were Indian-poachers turned Cavalry-gamekeepers.          The 'Aliens' were more illusive. The purpose or motivation was unclear and indeed it was not always certain that there was anyone responsible. The presence of an alien was suspected when the size of a file changed without any record of such a change in the accounting files or when a check total or hash total was inconsistent. Sometimes after a lot of investigation a suspected alien turned out to be just a bug in the system and the evidence was turned over to the maintenance people. Other times it turned out to be a bandit who really knew what he was about and had covered his traces well. Bandits came in all sorts but Indians were almost always male, young and hooked on computers.          The Cavalry were distributed world wide. Every MCI plant had its software support group to service the needs of the local customers and at least one member of each group was a designated expert on security. Fort Apache was the headquarters but because they were all in constant communication through the MCI network they functioned very much as a distributed team and there was a great deal of camaraderie. In many ways members of the Cavalry were closer together, even if they were thousands of miles apart, than they were to the people next door in their own local office.          Everyone was on first name terms. They had their photographs stored as bit-maps on the network and you could call up an image of another cavalry soldier in Melbourne or Tokyo at the touch of a button.          When someone tracked down a hacker and worked out how the trickster had done his dirty work, the story would be stuck into the noticeboard file on the network and everyone got to know about it. Hints on how to identify and trap were also posted but this was often considered too insecure for the most secret methods and these were distributed by Fort Apache using good old post.          The greatest accolade was to have a hacking or an anti-hacking technique named after you, so if you wanted to catch a hacker you might set a 'Passold tripwire' or install a 'Keto Tracer'. You could also say that a particular hacker was using a 'Morris Worm' or a 'Blackford Boomerang'.          The ethos of the Wild West was everywhere. The guys in the lab, which Allan now joined, treated the whole thing as an adventure game, and outwitting an illusive Indian was their greatest triumph. When the evidence was eventually put together identifying some miscreant, it was handed over to the legal division of MCI for action. They had a name for the people in the legal department too. They called them 'The Hitmen'.          The Cavalry did this part of the job with great glee. It was one of the rules of the game. The enemy was zapped and would conveniently disintegrate and disappear from the network. Seldom did they actually get a person's real name. Usually the closest they got to people and the probable fate of the enemy, was the directory user-name. It was a sanitized affair with no messy consequences.          Before they were fully identified, some Indians were given names like 'Cochise' and 'Hiawatha' and their exploits lived on in the mythology which seemed to be the main topic of conversation at coffee. Everyone had his own favourite and the others listened to the stories over and over again.          ‘Sitting Bull found that the ethernet cable passed through his room. So he built himself an ethernet monitor and read the passwords on the cable before they reached the machine and got encrypted. Then he thought he would do everyone a favour by checking that the passwords were correct. The other users didn't twig anything was wrong until he started warning them that they should change their passwords more often.’ Everyone fell about and then someone would top it with another story.          Assembling the evidence could be fun too since it often required considerable computer expertise just to understand what had happened and the Cavalry got a good deal of sardonic amusement at the pathetically ignorant queries they often got from the legal division asking for clarification, for example - ‘You state in your submission that the person identified by the code number 1 stole the shell of the person identified as no 2. You do not state what no 2 did when deprived of that shell.’          Bandits were usually boring, but sometimes one came along which gave them a sporting run. These they honoured with names like 'Jessie James' and 'Billy the Kid'. The evidence was also usually boring, consisting of lists of data showing illegal account withdrawals.          Aliens were given names like 'Android' and 'Green Slime'. Aliens were doubly nasty because you did not know that was not going to turn out to be an uninteresting bug and you had been wasting your time on a maintenance job. The Cavalry regarded the maintenance teams as the drones of the organisation and themselves as the elite. Olafsen's theoretical studies team were termed 'weirdos' and 'egg-heads'.          They had a fully equipped electronics lab because some of the techniques they used involved the use of specialist equipment. John Passold showed Allan round. One of the favourites was called an 'Automatic Sampling Unit'. It was a large black chip about three inches square which could be wired into a terminal or a microcomputer and which would record into its solid state memory a sample of everything that passed through the machine. Storage limitations meant that it could not store everything but it could be programmed to identify particular strings of characters and if these were typed by a user, the thing would take what was the equivalent of a photocopy of everything that followed for a fixed length of time. If you suspected that a user was using a forbidden password, a local engineer could wire an ASU - pronounced ‘ass-U’ into the suspect's terminal and it could be programmed for the forbidden password. If he typed it then you got a copy of what he was using the password for. John Passold was very proud of the ass-U. Allan recognised it immediately. He had cooked one to a crisp inside his own micro at Burnside Cottage.          To read the contents of an ass-U you needed an Automatic Sampler Reader - ASR or 'asser‘. You connected two micros together. One had an ass-U and the other had an asser plugged into it. That way you could read the contents in the ass-U within the other micro. An asser could also be used to wipe the contents of an ass-U or to insert new innocuous data into it. Before he left the lab that evening Allan had slipped an asser into his pocket.          Often and often he had had arguments with Jean on the subject of 'Conspiracy versus Cock-up' theories. Jean, being paranoid, had always favoured conspiracy and Allan, being, in his own opinion, well balanced, had thought that, in general, cock-up was the more likely. Now, however, he was beginning to favour a new hybrid theory. The Cocked-up Conspiracy Theory seemed to him to have a plausibility the other two lacked and here was an example. They bugged his micro with one hand and provided him with the wherewithal to circumvent it with the other.          It was too dangerous to keep the asser in his own apartment or in the pickup truck. He drove that very evening to Hironimo's farm and walked some distance up the valley beyond. It took only minutes to climb a crag beside the trail and wedge the asser in a plastic food container, into a crack.          Another technique of which John Passold was proud was the Keystroke Interval Signature System or 'kiss'. The idea was that when someone types on a keyboard, their fingers beat a unique rhythm on the keys. There is, for example, a characteristic time interval between the 't' and the 'h' and the 'e' of the word 'the' which is a dead give away. They had the 'kiss' of every MCI employee stored in a database and could tell straight away who was typing if they got more than a few dozen characters. Customers could have their employees characterised in this way too, so that hackers could be tracked immediately even if they were using a stolen password.          The name 'kiss' gave rise to innumerable corny jokes.          ’Cochine was on the network again last night.‘          ’Gee! Did he give you a kiss?‘          Allan sent a latter to Hamish describing the kiss technique and a postcard to Rosa, with a picture of Mount Aconcagua and a message to 'give my regards to Jack'.          But it was the virus data that Allan had come to study.          Within a computer there are unused spaces - suspected bad sectors on disc packs, unused space on message packets, housekeeping space used only for special purposes and so on. Viruses live in these spaces. They travel about on the network tacked on to the end of legitimate software and data, or they stow-away in the free space at the tail end of a package. Viruses lie dormant waiting for a certain date or for someone to run a particular program and then they can spring into life. The most effective viruses, like the AIDS virus, spread themselves about before they let anyone know they are there. And if they NEVER let anyone know? Then why should they not go on spreading for ever? What would happen to a biological virus which spread rapidly and did not do its host any harm? Why should a benign organism like that not conquer the world?          Allan collected the data on known viruses, the method of transfer from one computer to another, the method of detection, ways of avoiding detection. He was not too concerned about what the viruses did when they finally awoke from their slumber. That could be nice or nasty depending upon the taste of its perpetrator. But he was interested in the technology of detection. The Cavalry had developed a number of anti-viral programs which delved and probed into the hidden interstices of a computer. These programs were the 'immune response' of the computer world.          He knew that one of the reasons the AIDS virus or HIV was so dangerous was because it attacked the immune response itself and he wondered if there was a computer equivalent. Was it possible, for example, for a virus to examine the software running in a computer and detect when a program was about to examine the very locations where it was itself located? If it could do that then it could either move itself elsewhere or modify the detection program to ignore its own location.          And he was interested in more than viruses. A 'worm' is a program which bores its way into a computer by its own efforts. It does not piggyback on legitimate data and software. A worm can penetrate computer security protections by means of a few simple stratagems. People are careless with passwords. A good password is arbitrary and contains some numbers, but because they have difficulty remembering arbitrary strings of characters people use their own names, and the names of their wives or husbands, and their own names backwards, and the name of their dog, cat or house, or they use a normal word in the English language or American or whatever. Word processing programs have huge lists of words and it is not hard to get hold of a list of people's names. Microcomputers can zip through these lists trying each one in turn in a few hours and before long they are almost certain to hit on the password of some user who has been careless.          Once the worm is inside a computer it can look at its list of users. On a network most people have access to more than one computer so the chances are that your careless user has a directory on some other computer within the network and the chances are he or she has used the same password on both. So the worm tries the same username and password on every other computer in the network. It will probably succeed. And so the worm spreads and spreads. Worms and viruses, they get about.          Because Allan's task was one of those 'it would be nice if we had the time' kind of jobs, he could wander about without pressure of time. He spent many hours in the main library, and browsing through the virus history files on the network. No one minded if he didn't work normal hours in the lab and he actually spent a lot of time in his own apartment with his personal micro, running mathematical models of virus and worm epidemics. Much depended, he found, on the 'latency' of a virus, the length of time between infection and the point at which the virus made its presence known.          It also occurred to him that a worm equipped with the 'open sesame' password for the secret passage chip would spread like a domino cascade on the MCI network. He ran a model and found that it would have infected every computer within minutes of introduction. The speed was astounding.          He lay on his bed with his eyes on the Arisaig sands and thought about that.