'Well I'm damned,' he said. 'That's the first time . . . what the hell could have caused that?'

  He got no answer from the technician. Brady pulled the sleeves of his jumper down his arms, feeling cold and shivery. For no reason that he could identify he felt afraid, the laboratory becoming claustrophobic, threatening.

  He turned and left the room, his heart racing, his mind registering nothing but a strong, almost violent urge to get away from the place.

  As he fairly shot into the corridor, ignoring his jacket which hung just inside the laboratory door, he realized that his Section Chief, Andrew Haddingham, was strolling easily towards him, looking half puzzled, half amused. Haddingham was in thoughtful conversation with the lean, greying figure of the Department Superintendent, George Campbell. Campbell was a sour-faced Scot, a man who had little tolerance for the personal side of his employees' lives. He frowned as he witnessed Brady's slight dishevelment, and clamped his teeth on his unlit pipe in a gesture of annoyance.

  'What's the matter, Dan?' said Haddingham with a smile, as the three men met. 'You look spooked.'

  Brady nodded, and tried a slight grin back. He was aware of Campbell's intense, disapproving scrutiny. Dammit, he thought, at least I'm still working seriously this close to the holidays.

  He liked Haddingham, though, and got on well with the plump man. Haddingham was only slightly younger than the Supervisor, perhaps fifty-five, but he was far younger at heart and had an enthusiasm for ideas and projects that could spark even the dullest of the Ministry minds. Unmarried, and rather private about his past, Haddingham was a regular visitor at Brady's home.

  'A touch of claustrophobia,' Brady said, and glanced at Campbell. 'Been stuck in the laboratory a few hours too many.'

  Campbell, to Brady's surprise, allowed a genuine smile to touch his lips; his grey eyes flashed with something approaching pleasure. 'Good to see you working so hard, Mister Brady,' he said. 'I hope we'll be seeing some positive results from you in the coming year. Excuse me gentlemen, I have a train . . .'

  Campbell walked off, left hand in the pocket of his grey suit jacket. Brady stared after him, then glanced at Haddingham and laughed wearily. 'Never lets up, does he?'

  'Not on anybody, Dan,' said Haddingham, running a hand through his unkempt brown hair. 'I feel shell shocked myself, just now. Been hauled over the coals for the whole department.'

  'His way of saying Happy Christmas,' grinned Brady. 'I'd buy you a drink, but my house is a disaster zone . . .'

  He was about to turn away and fetch his jacket when Haddingham tugged at his arm, questioned the younger man with his gaze, then said, 'You really are spooked, Dan. What happened in there?'

  Brady hesitated just a second before deciding not to tell the other man what had occurred . . . not yet. 'Got a strange result, that's all. I'll tell you about it next year.'

  'A strange result sends you running scared from the room? What is it, Dan?'

  Brady shrugged, disliking Haddingham's sudden intensity, the way he was intuiting Brady's genuine sense of fear. 'As I said, claustrophobia, too close to Christmas. . . it really is nothing Andrew. I'm on edge, that's all.'

  Haddingham shrugged, smiled and reached out a hand to the younger man. 'Happy Christmas to you, then, Dan. And to the family. Enjoy yourselves . . .'

  'We shall. First Christmas in a new home; got to make it something special.'

  It had really been Alison who had fallen in love with the house at Brook's Corner, that previous March. Their town house in West London had suddenly - for no perceptible reason - become too small; it was perhaps because of Marianna's great enthusiasm for "projects", involving cutting paper, using clay, and sticking bits and pieces of disposable carton and package to make buildings and cars, all of which meant that living rooms, bedrooms, even bathrooms, became cluttered and untidy. And with Dominick wanting to have a room where he could bring back his friends and play music at exceptionally loud volumes (he was eleven, but had already discovered more than twenty forms of contemporary rhythm and blues), Brady had, on impulse, decided to sell and move his family westwards, to the area around Pinewood, where houses could either be of exceptional expense, or of very reasonable price.

  They had been directed to the house at Brook's Corner because, at seventy-five thousand pounds, it would not stretch them that much, even though it was in need of considerable decoration. Alison Brady had taken one look at the place and adored it. Dan Brady himself was the sort of man who could be happy anywhere that his family were happy. The house struck him as too large, too cold and too isolated, but Alison's rapture at the thought of living there was overwhelming. While the children had chased about the overgrown, partly wooded grounds (over an acre!) he and Alison had come to the decision to buy, to paint three of the rooms, and to leave the greater part of the needed modernisation for a year or so while they saved a little capital.

  They had moved in in June, and made a presentable lawn at the back, gravelled the driveway at the front, and found that rapidly, almost inevitably, they had expanded - as a family - to fill every nook and cranny of the place.

  Brook's Corner was just ten miles from the Ministry of Defence Institute at Hillingvale, where Brady worked, and he drove those ten miles, now, fast and without due care to the conditions of the road. He half hoped Alison would be home, but she was conscientious, and very much involved with two MSc projects at the College where she worked, and from years of experience Brady knew that she would only take off the day before Christmas Eve, and would work on in her department until such time as her students would relinquish her.

  He was not surprised, then, to find the house in darkness. It was four in the afternoon, a gloomy, bitterly cold day, and the central heating was off - one of the children fiddling with it, no doubt. Briskly he turned the radiators on, then poured himself a gin with tonic, going into the lounge where he set a log fire, but refrained from lighting it. In the corner of the lounge the Christmas tree was an immense forest of a structure, rising to the ceiling, shedding needles in spiky layers, and half covered with a mess of tinsel and coloured streamers - Marianna's ineffective attempt to decorate the tree, and an effort that would have to be discreetly corrected before Christmas Eve itself.

  Both Marianna and Dominick were at the Newmans' (causing havoc, no doubt) and Alison would pick them up on her way home from the college. That would be within a few minutes, so Brady took the opportunity to relax, feet up on one of the armchairs, gin and tonic freshened, a well-creased copy of Omni propped up before him.

  At four thirty it began to rain, the windows shaking slightly with the driving force of the dusk wind. The lounge was large and not yet completely draughtproof and Brady shivered as a cool breeze tickled his neck. Fragments of leaf that had been caught in the chimney fell into the grate, startling him. He got up, draining his drink, and glanced at his watch.

  Alison was very late. They should all have been home some time before.

  As he was about to pick up the phone to call the Newmans, it rang; Alison was on the line. 'Dan? It's Alison. Listen, I'm really stuck here. Probably for an hour . . .'

  'An hour! Oh for God's sake . . .'

  'It can't be helped. I'm behind with my own work. Pete Wright's project took a lot of reading. I've only just finished with him.'

  Brady felt a touch of irritation. He was rapidly trying to get into the spirit of the impending Christmas, and very much wanted to spend time this evening tidying the tree, and getting the last paper-chains slung in the downstairs rooms. He was finished with Hillingvale for the rest of the year, and chauvinistically felt a touch of resentment that Alison wouldn't finish with her own work place with equal enthusiasm.

  'Never mind,' he said. 'Get home as quickly as you can. I'll get supper going. How about the kids?'

  'Could you pick them up? The Newmans will be screaming murder by now. Would you mind?'

  'Okay. Hurry home.'

  Before he left he set the log fire alight, so that they would all come home to a cosy lounge. It was only a twenty minute round trip to John Newman's.

  And he wouldn't stay for a drink.

  Alison almost called Dan right back again, just to say that there was cold pork to be used up for supper that evening, and before they started on anything else, but she refrained. Dan hated her to fuss about the house and kitchen, liking to share the responsibility for all those drab and irritating chores that make a household run smoothly. He was a good cook, if one of erratic inclination, and their only real point of difference in the kitchen (in twelve years of marriage) was that Dan tended to cook extravagantly, and in quantities more suited to a barracks than a family of four, whereas Alison practiced a frugality instilled upon her by both her childhood, and her year in Kenya.

  She left her small second-floor office, turning out the light as she did so, and walked briskly along the corridor to the extensive library. She only really needed an hour to cross-check three references for her paper (with Pete Wright) on zonal agriculture on clay-based river terraces, but she wanted to get it done before tonight because she knew that tomorrow - the last day before the Christmas break for the staff - there would be no work possible in the atmosphere of drunken boisterousness.

  On the way to the library she picked up her coat, ready to leave as soon as possible.

  Alison Brady was thirty-four years old, a sprightly, energetic woman, thin to the point of being skinny, but content to be so because she loathed the idea of fat people, and of becoming plump and unfit herself. She was a sports fanatic, playing at least half an hour's badminton every day, and was increasingly scornful of Dan for neglecting his body so much.

  Like husband Dan, Alison was an informal dresser, preferring jeans and a jumper to tailored skirts and blouses; but there was an elegance about her that made her always seem perfectly dressed for any occasion. She wore her dark hair naturally wavy, and swept it back from her forehead; she knew the style suited her, and she was not by any means averse to the flattering attentions of her teenage male students.

  In the library she dumped her coat and papers on one of the desks nearest to the door and walked into the complex of rows of books and journals to seek the three journals she wished to consult. Pete Wright was working busily at the back of the library, seemingly unexhausted by the marathon supervision session with his tutor that afternoon. There were no other students or staff in the library; of course not. It was three days to Christmas and only the workaholics were left.

  Later, in the peace of her own house and lying still in the darkness, she would be able to remember the exact moment at which she had known someone else had entered the library. She hadn't heard anything, neither the door opening and shutting, nor a footfall; she hadn't seen anything, or smelled anything. It was a sensation as intangible and discrete as it was potent and certain. As she stood leafing through the Journal of Industrial Agriculture she just knew that a third party had entered the library, and was walking down the aisle of books towards her.

  She didn't bother to look up, merely stood closer to the side of the narrow alleyway between the shelves to let the person pass. After a second or two she realised that he had stopped and was staring at her, and with just the slightest of unpleasant sensations on her skin she glanced round to see who it was.

  'Oh God!'

  The words came as involuntarily as the journal slipping from her fingers. The book hit the floor with a crash, and Alison reached down, confused and upset, to retrieve it.

  She looked both ways along the aisle. Her knees were like jelly, hardly able to support her weight as she walked slowly out from the bookshelves, frightened and disturbed by her certain knowledge that someone had walked up behind her.

  The student was gone. She was alone in the library. The room was empty, cold, and musty with the smell of old journals; rain beat noisily against the high windows; wind shook the overhead strip-lights.

  She placed her journals on one of the tables and sat down, her hands shaking, her whole body trembling with fright. She stared across the room at the journal-shelves, and the dark, deserted gangways between them.

  Somewhere in that stillness the pages of a book were noisily turned, as if blown in a wind. A moment later there was silence again.

  But as Alison listened to the heavy silence, and stared at the shelves of books, she could not shake off the idea -powerfully felt - that someone was standing in the nearest aisle, intently and deliberately watching her.

  1

  * * *

  Later, he would think back to these cold, frantically busy days before Christmas and try to discern, among the chaos of experiments and travel and meetings, some clue as to what had happened, some hint as to the beginning of the tragedy that would soon sweep through his life.

  At the age of thirty-five Daniel Brady was fully immortal. A tall, leanly-built man in the full flush of health, and with a secure and challenging research position in t he Ministry of Defence at Hillingvale, he could no more have seriously contemplated his own mortality than he could have changed the flow of time. Death, if certainly a reality to him, was nevertheless a reality one step removed, something that happened to others. It was not a considera-t ion that he applied to himself, or to his young wife, Alison, or to his two growing children. His concerns were for work, for the research project that was only giving very tentative results, and for his new house in Berkshire which was too big, too cold, and probably a very ill-considered buy; and his youngest child, six-year-old Marianna, was not settling in at school, and neither he nor Alison could understand why.

  Worries about his family intruded upon the concentra-tion necessary for him to conduct his research properly; concerns for his research likewise affected him at home: during the rainy autumn he had been broody, distant, distracted. He was well aware that results were essential in his line of work, and in particular in this place of work that had so readily accepted him from University, ten years before. The Ministry of Defence had small research installations scattered over the length and breadth of Britain. It was considered a considerable achievement to be invited to work in one of them. It was very common indeed for a man or woman to leave the Ministry's employ after two or three unsuccessful years.

  Three days before Christmas Dan Brady had set up his study for one last attempt to get some results in the old year, prior to despairingly closing down the action until January 3rd. In the months to come, when he would have ample opportunity to contemplate these last happy, if frustrating days, he would see the first hint that at that time he had already been 'marked".

  'Are we ready to go?'

  Brady sat before two green-tinted screens, watching the solid-line traces upon one and the regular, wavy patterns on the other. In a small, enclosed cage a sullen looking female fat-tailed gerbil sat watching the blank walls of her environment. She couldn't see Brady, nor could she hear, nor smell, nor feel vibration through the wall of her prison. Brady's sole contact with her was through the cerebellar trace on the screen; the animal's hind-brain was active, and actively registering.

  The young man who worked as Brady's research assistant made some final adjustments to the various pieces of equipment, then sat down at his own station and called, 'Ready.' He was thin and willowy, his eyes framed by huge, silver rimmed spectacles. He wore the white coat of a lab technician, whereas Brady was dressed informally, casually (his department supervisor said scruffily) in a voluminous roll neck, and grey cord slacks. Brady hated formality, and the formal attire of the laboratory.

  He leaned forward and peered beyond a glass screen into a strange landscape . . .

  It was night and the desert was cold. There was no moon, but an eerie light picked out the shapes of boulders, stubby cactus, and the solitary, upright shape of an animal, feeding nervously on a locust. The creature was small and rat-like, its feet abnormally long, and it balanced precariously in the danger-filled darkness, ready to flee at the first hint of attack. Pachyuromys duprasi was a native of deserts in East Africa; a nocturnal predator of locusts, spiders and

  other night-feeding creatures it was, itself, the natural prey of the sand cat.

  Into this tiny desert, bordered not by the lusher vegetation of a river terrace, or by high, snow-capped mountains, but rather by perspex walls darkened to allow the illusion of night, into this miniature world the first danger came.

  The sand cat betrayed its stealthy approach by the faintest of drumming on the reverberant sand. The gerbil straightened, ceased chewing, then peered to the right and the left through wide, shining eyes. The cat leapt towards it in an instant, but the gerbil was faster: it bounded across the dry, chill landscape until it fetched up against the invisible wall across its territory.

  The pursuit was not continued; the cat was illusory, generated by the research assistant from across the environment.

  But in that single instant of escape something happened fifty yards distant, where Brady sat watching the screens, and the imprisoned female animal. First, on the broader of the two screens, which showed four single, unbroken traces, a tiny, almost fleeting peak of activity had occurred. On the smaller screen, which showed the cerebellar activity of the female gerbil, three powerful, sustained peaks registered a dramatic change in the unconscious awareness of the tiny animal.

  Out of sight of her mate, unaware of the danger, the female's own hindbrain had registered the input of a warning signal; not by sound, nor by sight, nor by vibration; an extra-sensory signal had been relayed from brain to brain, and then to machinery; a warning signal that had been observed!

  Brady sat back in his chair and allowed himself the luxury of a thin smile, a token gesture of self-congratula-tion. 'What did we get?' called the assistant, and Brady said, 'A hint . . . just a hint. The female registered the warning very powerfully, but our own detectors spotted something too. Just a hint . . .'

  'Stronger than Trial 17?'

  'Maybe not. But a damn sight stronger than nothing at all!'