Enigma

1

BLETCHLEY WAS A railway town. The great main line from London to Scotland split it down the middle, and then the smaller branch line from Oxford to Cambridge sliced it into quarters, so that wherever you stood there was no escaping the trains: the noise of them, the smell of their soot, the sight of their brown smoke rising above the clustered roofs. Even the terraced houses were mostly railway-built, cut from the same red brick as the station and the engine sheds, constructed in the same dour, industrial style.

The Commercial Guesthouse, Albion Street, was about five minutes' walk from Bletchley Park and backed on to the main line. Its owner, Mrs Ethel Armstrong, was, like her establishment, a little over fifty years old, solidly built, with a forbidding, late-Victorian aspect. Her husband had died of a heart attack a month after the outbreak of war, whereupon she had converted their four-storey property into a small hotel. Like the other townspeople – and there were about seven thousand of them – she had no idea of what went on in the grounds of the mansion up the road, and even less interest. It was profitable, that was all that mattered to her. She charged thirty-eight shillings a week and expected her five residents, in return for meals, to hand over all their food-rationing coupons. As a result, by the spring of 1943, She thousand pounds in War Savings Bonds and enough edible goods hoarded in her cellar to open a medium-sized grocery store.

It was on the Wednesday that one of her rooms had become vacant, and on the Friday that she had been served a billeting notice requiring her to provide accommodation to a Mr Thomas Jericho. His possessions from his previous address had been delivered to her door that same morning: two boxes of personal effects and an ancient iron bicycle. The bicycle she wheeled into the back yard. The boxes she carried upstairs.

One carton was full of books. A couple of Agatha Christies. A Synopsis of Elementary Results in Pure and Applied Mathematics, two volumes, by a fellow named George Shoobridge Garr. Principia Mathematical, whatever that was. A pamphlet with a suspiciously Germanic ring to it – On Computable Numbers, with an Application to the Entscheidungs problem – inscribed 'To Tom, with fond respect, Alan'. More books full of mathematics, one so repeatedly read it was almost falling to pieces and stuffed full of markers – bus and tram tickets, a beer mat, even a blade of grass. It fell open at a heavily underlined passage:

there is one purpose at any rate which the real mathematics may serve in war. When the world is mad, a mathematician may find in mathematics an incomparable anodyne. For mathematics is, of all the arts and sciences, the most remote.

Well, the last line's true enough, she thought. She closed the book, turned it around and squinted at the spine: A Mathematician's Apology by G. H. Hardy, Cambridge University Press.

The other box also yielded little of interest. A Victorian etching of King's College Chapel. A cheap Waralarm clock, set to go off at eleven, in a black fibre case. A wireless. An academic mortarboard and a dusty gown. A bottle of ink. A telescope. A copy of The Times dated 23 December 1942, folded to the crossword, which had been filled in by two different hands, one very small and precise, the other rounder, probably feminine. Written above it was 2712815. And, finally, at the bottom of the carton, a map, which, when she unfolded it, proved not to be of England, or even (as she had suspected and secretly hoped) of Germany, but of the night sky.

She was so put off by this dreary collection that when, at half past midnight that night, there was a knock on the door and another two suitcases were delivered by a small man with a northern accent, she didn't even bother to open them but dumped them straight in the empty room.

Their owner arrived at nine o'clock on Saturday morning. She was sure of the time, she explained later to her next-door neighbour, Mrs Scratchwood, because the religious service was just ending on the wireless and the news was about to start. And he was exactly as she'd suspected he would be. He wasn't very tall. He was thin. Bookish. Ill-looking, and nursing his arm, as if he'd just injured it. He hadn't shaved, was as white as – well, she was going to say 'as a sheet', but she hadn't seen sheets that white since before the war, certainly not in her house. His clothes were of good quality, but in a mess: she noticed there was a button missing on his overcoat. He was pleasant enough, though. Nicely spoken. Very good manners. A quiet voice. She'd never had any children herself, never had a son, but if she had, he would have been about the same age. Well, let's just say he needed feeding up, anyone could see that.

She was strict about the rent. She always demanded a month in advance – the request was made down in the hall, before she took them up to see the room – and there was usually an argument, at the end of which she grumpily agreed to settle for two weeks. But he paid up without a murmur. She asked for seven pounds six shillings and he gave her eight pounds, and when she pretended she hadn't any change, he said: 'Fine, give it me later.' When she mentioned his ration book he looked at her for a moment, very puzzled, and then he said (and she would remember it for the rest of her life): 'Do you mean this?'

'Do you mean this? She repeated it in wonderment. As if he'd never seen one before! He gave her the little brown booklet – the precious weekly passport to four ounces of butter, eight ounces of bacon, twelve ounces of sugar – and told her she could do what she liked with it. 'I've never had any use for it.'

By this time she was so flustered she hardly knew what she was doing. She tucked the money and the ration book into her apron before he could change his mind and led him upstairs.

Now Ethel Armstrong was the first to admit that the fifth bedroom of the Commercial Guest House was not up to much. It was at the end of the passage, up a little twist of stairs, and the only furniture in it was a single bed and a wardrobe. It was so small the door wouldn't open properly because the bed got in the way. It had a tiny window flecked with soot which looked out over the wide expanse of railway tracks. In two and a half years it must have had thirty different occupants. None had stayed more than a couple of months and some had refused to sleep in it at all. But this one just sat on the edge of the bed, squeezed in between his boxes and his cases, and said wearily, 'Very pleasant, Mrs Armstrong.'

She quickly explained the rules of the house, Breakfast was at seven in the morning, dinner at six thirty in the evening, 'cold collations' would be left in the kitchen for those working irregular shifts. There was one bathroom at the far end of the passage, shared between the five guests. They were permitted one bath a week each, the depth of water not to exceed five inches (a line was marked on the enamel) and he would have to arrange his turn with the others. He would be given four lumps of coal per evening to heat his room. The fire in the parlour downstairs was extinguished at 9 p.m., sharp. Anyone caught cooking, drinking alcohol or entertaining visitors in their room, especially of the opposite sex – he'd smiled faintly at that – would be evicted, balance of rent to be paid as a forfeit.

She'd asked if he had any questions, to which he made no reply, which was a mercy, because at that moment a nonstop express shrieked past at sixty miles an hour no more than a hundred feet from the bedroom window, shaking the little room so violently that Mrs Armstrong had a brief and horrifying vision of the floor giving way and them both plummeting downwards, down through her own bedroom, down through the scullery, crashing down to land amid the waxy legs of ham and tinned peaches so carefully stacked and hidden in her Aladdin's cave of a cellar.

'Well, then,' she said, when the noise (if not yet the house) had finally subsided, Til leave you to get some peace and quiet.'

Tom Jericho sat on the edge of the bed for a couple of minutes after listening to her footsteps descending the stairs. Then he took off his jacket and shirt and examined his throbbing forearm. He had a pair of bruises just below the elbow as neat and black as

damsons, and he remembered now whom Skynner had always reminded him of: a prefect at school called Fane, the son of a bishop, who liked to cane the new boys in his study at teatime, and make them all say 'thank you, Fane' afterwards.

It was cold in the room and he started to shiver, his skin puckering into rashes of gooseflesh. He felt desperately tired. He opened one of his suitcases and took out a pair of pyjamas and changed into them quickly. He hung up his jacket and thought about

unpacking the rest of his clothes, but decided against it. He might be out of Bletchley by the next morning.

That was a point – he passed his hand across his face -he'd just given away eight pounds, more than a week's salary, for a room he might not need. The wardrobe vibrated as he opened it and the wire coat hangers sounded a melancholy chime. Inside it stank of mothballs. He quickly shoved the cardboard boxes into it and pushed the cases under the bed. Then he drew the curtains, lay down on the lumpy mattress, and pulled the blankets up under his chin.

For three years Jericho had led a nocturnal life, rising with the darkness, going to bed with the light, but he'd never got used to it. Lying there listening to the distant sounds of a Saturday morning made him feel like an invalid. Downstairs someone was running a bath. The water tank was in the attic directly above his head, and the noise of it emptying and refilling was deafening. He closed his eyes and all he could see was the chart of the North Atlantic. He opened them and the bed shook slightly as a train went by and that reminded him of Claire. The 15.06 out of London Euston – 'calling at Willesden, Watford, Apsley, Berkhamsted, Tring, Cheddington and Leighton Buzzard, arriving Bletchley four-nineteen – he could recite the station announcement even now, and see her now as well. It had been his first glimpse of her.

This must have been – what? – a week after the break into Shark? A couple of days before Christmas, anyway. He and Logie, Puck and Atwood had been ordered to present themselves at the office block in Broadway, near St James's tube station, from which Bletchley Park was run. 'C' himself had made a little speech about the value of their work. In recognition of their Vital breakthrough', and on the orders of the Prime Minister, they had each received an iron handshake and an envelope containing a cheque for a hundred pounds, drawn on an ancient and obscure City bank. Afterwards, slightly embarrassed, they'd said goodbye to one another on the pavement and gone their various ways – Logie to lunch at the Admiralty, Puck to meet a girl, Atwood to a concert at the National Portrait Gallery – and Jericho back to Euston to catch the train to Bletchley, 'callingat Willesden, Watford, Apsley

There would be no more cheques now, he thought. Perhaps Churchill would ask for his money back.

A million tons of shipping. Ten thousand people. Forty-six U-boats. And that was just the beginning of it.

'It's everything. It's the whole war.'

He turned his face to the wall.

Another train went by, and then another. Someone else began to run a bath. In the back yard, directly beneath his window, Mrs Armstrong hung the parlour carpet over the washing line and began to beat it, hard and rhythmically, as if it were a tenant behind with his rent or some prying inspector from the Ministry of Food.

Darkness closed around him.

The dream is a memory, the memory a dream.

A teeming station platform – iron girders and pigeons fluttering against a filthy glass cupola. Tinny carols playing over the public address system. Steel light and splashes of khaki.

A line of soldiers bent sideways by the weight of kitbags runs towards the guard's van. A sailor kisses a pregnant woman in a red hat and pats her bottom. School children going home for Christmas, salesmen in threadbare overcoats, a pair of thin and anxious mothers in tatty furs, a tall, blonde woman in a well-cut, ankle-length grey coat, trimmed with black velvet at the collar and cuffs. A prewar coat, he thinks, nothing so fine is made nowadays…

She walks past the window and he realises with a jolt that she's noticed he is staring at her. He glances at his watch, snaps the lid shut with his thumb and when he looks up again she's actually stepping into his compartment. Every seat is taken. She hesitates. He stands to offer her his place. She smiles her thanks and gestures to show there 's just sufficient room for her to squeeze between him and the window. He nods and sits again with difficulty.

Doors slam along the length of the train, a whistle blows, they shudder forwards. The platform is a blur of waving people.

He's wedged so tightly he can barely move. Such intimacy would never have been tolerated before the war, but nowadays, on these endless uncomfortable journeys, men and women are always being thrown together, often literally so. Her thigh is pressed to his, so hard he can feel the firmness of muscle and bone beneath the padding of her flesh. Her shoulder is to his. Their legs touch. Her stocking rustles against his calf. He can feel the warmth of her, and smell her scent.

He looks past her and pretends to stare out of the window at the ugly houses sliding by. She's much younger than he thought at first. Her face in profile is not conventionally pretty, but striking – angular, strong – he supposes 'handsome' is the word for it. She has very blonde hair, tied back. When he tries to move, his elbow brushes the side of her breast and he thinks he might die of embarrassment. He apologies profusely but she doesn't seem to notice. She has a copy of The Times, folded up very small so that she can hold it in one hand.

The compartment is packed. Servicemen lie on the floor and jam the corridor outside. An RAF corporal has fallen asleep in the luggage rack and cradles his kit bag like a lover. Someone begins to snore. The air smells strongly of cheap cigarettes and unwashed bodies. But gradually, for Jericho, all this begins to disappear. There are just the two of them, rocking with the train. Where they touch his skin is burning. His calf muscles ache with the strain of neither moving too close nor drawing apart.

He wonders how far she's going. Each time they stop at one of the little stations he fears she might get off. But no: she continues to stare down at her square of newsprint. The dreary hinterland of northern London gives way to a dreary countryside, monochrome in the darkening December afternoon – frosted fields barren of livestock, bare trees and the straggling dark lines of hedgerows, empty lanes, little villages with smoking chimneys that stand out like smudges of soot in the white landscape.

An hour passes. They're clear of Leighton Buzzard and within five minutes of Bletchley when she suddenly says: 'German town partly in French disagreement with Hamelin.'

He isn't sure he's heard her properly, or even if the remark is addressed to him.

'I'm sorry?'

'German town partly in French disagreement with Hamelin.' She repeats it, as if he's stupid. 'Seven down. Eight letters.'

'Ah yes,' he says. 'Ratisbon.'

'How do you get that? I don't think I've even heard of it. 'She turns her face to him. He has an impression of large features – a sharp nose, a wide mouth – but it is the eyes that hold him. Grey eyes – a cold grey, with no hint of blue. They're not dove-grey, he decides later, or pearl-grey. They're the grey of snow clouds waiting to break.

'It's a cathedral city. On the Danube, I believe. Partly in French – well, bon, obviously. Disagreement with Hamelin. That's easy. Hamelin – Pied Piper – rats. Rat wbon. Rat is good. Not the view in Hamelin.'

He starts to laugh then stops himself. Just hark at yourself, he thinks, you 're babbling like an idiot.

'Fill up ten. Nine letters.'

'That's an anagram,' he says immediately. 'Plentiful.'

'Morning snack as far as it goes. Five letters.'

'Ambit.'

She shakes her heard, filling in the answers. 'How do you get it so quickly?'

'It's not hard. You learn to know the way they think. Morning- that's a.m., obviously. Snack as far as it goes – bit with the e missing. As far as it goes – well, within one's ambit. One's limit. May I?'

He reaches over and takes the paper and pencil. Half his brain studies the puzzle, the other half studies her – how she takes a cigarette from her handbag and lights it, how she watches him, her head resting slightly to one side. Aster, tasso, loveage, landau… It's the first and only time in their relationship he's ever fully in control, and by the time he's completed the thirty clues and given her back the paper they 're pulling through the outskirts of a small town, crawling past narrow gardens and tall chimneys. Behind her head he sees the familiar lines of washing, the air raid shelters, the vegetable plots, the little red-brick houses coated black by the passing trains. The compartment darkens as they pass beneath the iron canopy of the station. 'Bletchley,' calls the guard. 'Bletchley station!'

He says, 'I'm afraid this is my stop.'

'Yes.' She looks thoughtfully at the finished crossword, then turns and smiles at him. 'Yes. D'you know, I rather guessed it might be.'

'Mr Jericho!' someone calls. 'Mr Jericho!'

'Mr Jericho!'

He opened his eyes. For a moment he was disoriented. The wardrobe loomed over him like a thief in the dim light.

'Yes.' He sat up in the strange bed. 'I'm sorry. Mrs Armstrong?'

'It's a quarter past six, Mr Jericho.' She was shouting to him from halfway up the stairs. 'Will you be wanting supper?'

A quarter past six? The room was almost dark. He pulled his watch out from beneath his pillow and flicked it open. To his astonishment he found he had slept through the entire day.

'That would be very kind, Mrs Armstrong. Thank you.'

The dream had been disturbingly vivid – more substantial, certainly, than this shadowy room – and as he threw off the blankets and swung his bare feet on to the cold floor, he felt himself to be in a no-man's-land between two worlds. He had a peculiar conviction that Claire had been thinking of him, that his subconscious had somehow acted like a radio receiver and had picked up a message from her. It was an absurd thought for a mathematician, a rationalist, to entertain, but he couldn't rid himself of it. He found his sponge-bag and slipped his overcoat over his pyjamas.

On the first floor a figure in a blue flannel dressing gown and white paper curlers hurried out of the bathroom. He nodded politely but the woman gave a squeak of embarrassment and scuttled down the passage. Standing at the basin, he laid out his toiletries: a sliver of carbolic soap, a safety razor with a six-month-old blade, a wooden toothbrush worn down to a fuzz of bristles, an almost empty tin of pink tooth powder. The taps clanked. There was no hot water. He scraped at his chin for ten minutes until it was red and pricked with blood. This was where the devil of the war resided, he thought, as he dabbed at his skin with the hard towel: in the details, in the thousand petty humiliations of never having enough toilet paper or soap or matches or baths or clean clothes. Civilians had been pauperised. They smelled, that was the truth of it. Body odour lay over the British Isles like a great sour fog.

There were two other guests downstairs in the dining room, a Miss Jobey and a Mr Bonnyman, and the three of them made discreet conversation while they waited for their food. Miss Jobey was dressed in black with a cameo brooch at her throat. Bonnyman wore mildew-coloured tweeds with a set of pens in his breast pocket and Jericho guessed he might be an engineer on the bombes. The door to the kitchen swung open as Mrs Armstrong brought in their plates. 'Here we go,' whispered Bonnyman. 'Brace yourself old boy.'

'Now, don't you go getting her worked up again, Arthur,' said Miss Jobey. She gave his arm a playful pinch, at which Bonnyman's hand slid beneath the table and squeezed her knee. Jericho poured them all a glass of water and pretended not to notice.

'It's potato pie,' announced Mrs Armstrong, defiantly. 'With gravy. And potatoes.'

They contemplated their steaming plates. 'How very, ah, substantial,' said Jericho, eventually. The meal passed in silence. Pudding was some kind of stewed apple with powdered custard. Once that had been cleared away Bonnyman lit his pipe and announced that, as it was a Saturday night, he and Miss Jobey would be going to the Eight Bells Inn on the Buckingham Road.

'Naturally, you're very welcome to join us,' he said, in a tone which implied that Jericho, naturally, wouldn't be welcome at all. 'Do you have any plans?'

'It's kind of you, but as a matter of fact I do have plans. Or, rather, a plan.'

After the others had gone, he helped Mrs Armstrong clear away the dishes, then went out into the back yard to check his bicycle. It was almost dark and there was a sharpness in the air that promised frost. The lights still worked. He cleaned the dirt off the regulation white patch on the mudguard and pumped some air into the tyres.

By eight o'clock he was back up in his room. At half past ten, Mrs Armstrong was on the point of laying aside her knitting to go up to bed when she heard him coming downstairs. She opened the door a crack, just in time to see Jericho hurrying along the passage and out into the night.

2

The moon defied the blackout, shining a blue torch over the frozen fields, quite bright enough for a man to cycle by. Jericho lifted himself out of the saddle and trod hard on the pedals, rocking from side to side as he toiled up the hill out of Bletchley, pursuing his own shadow, cast sharp on the road before him. From far in the distance came the drone of a returning bomber.

The road began to level out and he sat back on the saddle. For all his efforts with the pump, the tyres remained half-flat, the wheels and chain were stiff for want of oil. It was hard going, but Jericho didn't mind. He was taking action, that was the point. It was the same as code-breaking. However hopeless the situation, the rule was always to do something. No cryptogram, Alan Turing used to say, was ever solved by simply staring at it.

He cycled on for about two miles, following the lane as it continued to rise gently towards Shenley Brook End. This was hardly a village, more a tiny hamlet of perhaps a dozen houses, mostly farmworkers' cottages. He couldn't see the buildings, which sheltered in a slight hollow, but when he rounded a bend and caught the scent of woodsmoke he knew he must be close.

Just before the hamlet, on the left, there was a gap in the hawthorn hedge where a rutted track led to a little cottage that stood alone. He turned into it and skittered to a halt, his feet slipping on the frozen mud. A white owl, improbably huge, rose from a nearby branch and flapped soundlessly across the field. Jericho squinted at the cottage. Was it his imagination or was there a hint of light in the downstairs window? He dismounted and began to wheel his bike towards it.

He felt wonderfully calm. Above the thatched roof the constellations spread out like the lights of a city – Ursa Minor and Polaris, Pegasus and Cepheus, the flattened M of Cassiopeia with the Milky Way flowing through it. No glow from earth obscured their brilliance. You can at least say this for the blackout, he thought, it has given us back the stars.

The door was stout and iron-studded. It was like knocking on stone. After half a minute he tried again.

'Claire?' he called. 'Claire?'

There was a pause, and then: 'Who is it?'

'It's Tom.' He took a breath and braced himself, as if for a blow.

The handle turned and the door opened slightly, just enough to reveal a dark-haired woman, thirtyish, about Jericho's height. She was wearing round spectacles and a thick overcoat and was holding a prayer book.

'Yes?'

For a moment he was speechless. 'I'm sorry,' he said, 'I was looking for Claire.'

'She's not in.'

'Not in?' he repeated, hopelessly. He remembered now that Claire shared the cottage with a woman called Hester Wallace ('she works in Hut 6, she's a sweetie') but for some reason he had forgotten all about her. She did not look very sweet to Jericho. She had a thin face, split like a knife by a long, sharp nose. Her hair was wrenched back off a frowning forehead. 'I'm Tom Jericho.' She made no response. 'Perhaps Claire's mentioned me?'

'I'll tell her you called.'

'Will she be back soon?'

'I've no idea, I'm sorry.'

She began to close the door. Jericho pressed his foot against it. 'I say, I know this is awfully rude of me, but I couldn't possibly come in and wait, could I?'

The woman glanced at his foot, and then at his face. 'I'm afraid that's impossible. Good evening, Mr Jericho.' She pushed the door closed with surprising force.

Jericho took a step backwards on to the track. This was not a contingency envisaged in his plan. He looked at his watch. It was just after eleven. He picked up his bicycle and wheeled it back towards the lane, but at the last moment, instead of going out on to the road, he turned left and followed the line of the hedge. He laid the bicycle flat and drew into the shadows to wait.

After about ten minutes, the cottage door opened and closed and he heard the rattle of a bicycle being wheeled over stone. It was as he thought: Miss Wallace had been dressed to go out because she was working the midnight shift. A pinprick of yellow light appeared, wobbled briefly from side to side, and then began to bob towards him. Hester Wallace passed within twenty feet in the moonlight, knees pumping, elbows stuck out, as angular as an old umbrella. She stopped at the entrance to the lane and slipped on a luminous armlet. Jericho edged further into the hawthorn. Half a minute later she was gone. He waited a full quarter of an hour in case she'd forgotten something, then headed back to the cottage.

There was only one key – ornate and iron and big enough to fit a cathedral. It was kept, he recalled, under a piece of slate beneath a flowerpot. Damp had warped the door and he had to push hard to open it, scraping an arc on the flagstone floor. He replaced the key and closed the door behind him before turning on the light.

He had only been inside once before, but there wasn't much to remember. Two rooms on the ground floor: a sitting room with low beams and a kitchen straight ahead. To his left, a narrow staircase led up to a little landing. Claire's bedroom was at the front, looking towards the lane. Hester's was at the rear. The lavatory was a chemical toilet just outside the back door, reached via the kitchen. There was no bathroom.

A galvanised metal tub was kept in the shed next to the kitchen. Baths were taken in front of the stove. The whole place was cold and cramped and smelled of mildew. He wondered how Claire stuck it.

'Oh, but darling, it's so much better than having some ghastly landlady telling one what to do…'

Jericho took a couple of steps across the worn rug and stopped. For the first time he began to feel uneasy. Everywhere he looked he saw evidence of a life being lived quite contentedly without him – the ill-assorted blue-and-white china in the dresser, the vase full of daffodils, the stack of pre-war Vogues, even the arrangement of the furniture (the two armchairs and the sofa drawn up cosily around the hearth). Every tiny domestic detail seemed significant and premeditated. He had no business here.

He very nearly left at that moment. All that stopped him was the faintly pathetic realisation that he had nowhere else particularly to go. The Park? Albion Street? King's? His life seemed to have become a maze of dead ends.

Better to make a stand here, he decided, than run away again. She was bound to be back quite soon.

God, but it was cold! His bones were ice. He walked up and down the cramped room, ducking to avoid the heavy beams. In the hearth was white ash and a few blackened fragments of wood. He sat first in one armchair, then tried the other. Now he was facing the door. To his right was the sofa. Its covers were of frayed pink silk, its cushions hollowed and leaking feathers. The springs had gone and when you sat in it you sank almost to the floor and had to struggle to get out. He remembered that sofa and he stared at it for a long time, as a soldier might stare at a battlefield where a war had been irretrievably lost

They leave the train together and walk up the footpath to the Park. To their left is a playing field, ploughed into allotments for the Dig for Victory campaign. To their right, through the perimeter fence, is the familiar huddle of low buildings. People walk briskly to ward off the cold. The December afternoon is raw and misty, the day is leaking into dusk.

She tells him she's been up to London to celebrate her birthday. How old does he think she is?

He hasn 't a clue. Eighteen perhaps?

Twenty, she says triumphantly, ancient. And what was he doing in town?

He can't tell her, of course. Just business, he says. Just business.

Sorry she says, she shouldn't have asked. She still can't get the hang of all this 'need to know'. She has been at the Park three months and hates it. Her father works at the Foreign Office and wrangled her the job to keep her out of mischief. How long has he been here?

Three years says Jerico, she shouldn't worry, it'll get better.

Ah she says, that's easy for him to say, but surely he does something interesting?

Not really he says, but then he thinks that makes him sound boring, so he adds: 'Well, quite interesting, I suppose.'

In truth he's finding it hard to keep up his end of the conversation. It's distracting enough merely to walk alongside her. They lapse into silence.

There's a noticeboard close to the main gate advertising a performance of Bach's Musikalisches Opfer by the Bletchley Park Music Society. 'Oh, now look at that, 'she says, 'I adore Bach', to which Jericho replies with genuine enthusiasm, that Bach is his favourite composer. Grateful at last to have found something to talk about, he launches into a long dissertation about the Musikalisches Opfer's six-part fugue, which Bach is supposed to have improvised on the spot for King Frederick the Great, a feat equivalent to playing and winning sixty games of blindfold chess simultaneously. Perhaps she knows that Bach's dedication to the King – Regis lussu Cantio et Reliqua Canonica Arte Resoluta – rather interestingly yields the acrostic RICERCAR, meaning'to seek'?

No, oddly enough, she doesn 't know that.

This increasingly desperate monologue carries them as far as the huts where they both stop and, after another awkward pause, introduce themselves. She offers him her hand – her grip is warm and firm, but her nails are a shock: painfully bitten back, almost to the quick. Her surname is Romilly. Claire Romilly. It has a pleasant ring. Claire Romilly. He wishes her a merry Christmas and turns away but she calls him back. She hopes he won't think it too fresh of her, but would he like to go with her to the concert?

He isn 't sure, he doesn't know…

She writes down the date and time just above The Times crossword – 27 December at 8.15 – and thrusts it into his hands. She'll buy the tickets. She'll see him there. Please don't say no.

And before he can think of an excuse, she's gone. He's due to be on shift on the evening of the 27th but he doesn 't know where to find her to tell her he can't go. And anyway, he realises, he rather does want to go. So he calls in a favour he's owed by Arthur de Brooke and waits outside the assembly hall, and waits, and waits. Eventually, after everyone else has gone in, and just when he's about to give up, she comes running out of the darkness, smiling her apologies.

The concert is better than he'd hoped. The quintet all work at the Park and once played professionally. The harpsichordist is particularly fine. The women in the audience are wearing evening frocks, the men are wearing suits. Suddenly, and for the first time he can recall, the war seems a long way away. As the last notes of the third canon ('per Motum contrarium') are dying in the air he risks a

glance at Claire only to discover that she is looking at him. She touches his arm and when the fourth canon (*per Augmentationem, contrario Motu'j begins, he is lost.

Afterwards he has to go straight back to the hut: he's promised he 'd be back before midnight. 'Poor Mr Jericho,' she says, 'just like Cinderella…' But at her suggestion they meet again for the following week's concert – Chopin -and when that's over they walk down the hill to the station to have cocoa in the platform bujfet.

'So, 'she says, as he returns from the counter bearing two cups of brown froth, 'how much am I allowed to know about you?'

'Me? Oh, I'm very boring.'

'I don't think you 're boring at all. In fact, I've heard a rumour you're rather brilliant. 'She lights a cigarette and he notices again her distinctive way of inhaling, seeming almost to swallow the smoke, then tilting her head back and breathing it out through her nostrils. Is this some new fashion, he wonders? I suppose you're married?' she says.

He almost chokes on his cocoa. 'Good God, no. I mean, I would hardly be – '

'Fiancee? Girlfriend?'

'Now you 're teasing me.' He pulls out a handkerchief and dabs at his chin.

'Brothers? Sisters?'

'No, no.'

'Parents? Even you must have parents.'

'Only one still alive.'

'I'm the same, 'she says. 'My mother's dead.'

'How awful for you. I'm sorry. My mother, I must say, is very much alive.'

And so it goes on, this hitherto untasted pleasure of talking about oneself. Her grey eyes never leaving his face. The trains steam past in the darkness, trailing a wash of soot and hot air. Customers come and go. 'Who cares if we're without a light?' sings a crooner on the wireless in the corner, 'they can't blackout the moon…' He finds himself telling her things he's never really spoken of before – about his father's death and his mother's remarriage, about his stepfather (a businessman, whom he dislikes), about his discovery of astronomy and then of mathematics… '

'And your work now?' she says. 'Does that make you happy?'

'Happy?' He warms his hands on his cup and considers the question. 'No. I couldn't say happy. It's too demanding -frightening, even, in a way.'

'Frightening?' The wide eyes widen further with interest. 'Frightening how?'

'What might happen…' (You 're showing off, he warns himself, stop it.) 'What might happen if you get it wrong, I suppose.'

She lights another cigarette. 'You 're in Hut 8, aren 't you? Hut 8's the naval section?'

This brings him up with a jolt. He looks around quickly. Another couple are holding hands at the next table, whispering. Four airmen are playing cards. A waitress in a greasy apron is polishing the counter. Nobody seems to have heard.

'Talking of which,' he says, brightly, I think I ought to get back.'

On the corner of Church Green Road and Wilton Avenue she kisses him, briefly, on the cheek.

The following week it is Schumann, followed by steak-and-kidney pudding and jam roly-poly at the British Restaurant in Bletchley Road ('two courses for elevenpence') and this time it's her turn to talk. Her mother died when she was six, she says, and her father trailed her from embassy to embassy. Family has been a procession of nannies and governesses. At least she's learned some languages. She 'd wanted to join the Wrens, but the old man wouldn 't let her.

Jericho asks what London was like in the Blitz. 'Oh, a lot of fun, actually. Loads of places to go. The Milroy, the Four Hundred. A kind of desperate gaiety. We've all had to learn to live for the moment, don't you think?'

When they say goodbye she kisses him again, her lips to one cheek, her cool hand to the other.

In retrospect, it is around this time, in the middle of January, that he should have started keeping a record of his symptoms, for it is now that he begins to lose his equilibrium. He wakes with a feeling of mild euphoria. He bounces into the hut, whistling. He goes for long walks around the lake between shifts, taking bread to feed the ducks – just for the exercise, he tells himself, but really he is scanning the crowds for her, and twice he sees her, and once she sees him and waves.

For their fourth date (the fifth, if you count their meeting on the train) she insists they do something different, so they go to the County Cinema on the High Street to see the new Noel Coward picture, In Which We Serve.

'And you really mean to tell me you 've never once been here?'

They're queuing for tickets. The film's only been showing for a day and the line extends round the corner into Aylesbury Street.

'I haven't, actually, to be honest, no.'

'God, Tom, you are a funny old darling. I think I'd die stuck in Bletchley without the flicks to go to.'

They sit near the back and she laces her arm through bis. The light from the projector high up behind them makes a kaleidoscope of blues and greys in the dust and cigarette smoke. The couple next to them are kissing. A woman giggles. A fanfare of trumpets announces a newsreel and there, on the screen, long columns of German prisoners, an impossible number, are shown trekking through snow, while the announcer talks excitedly about Red Army breakthroughs on the eastern front. Stalin appears, presenting medals, to loud applause. Someone shouts: 'Three cheers for Uncle Joe!' The lights come up, then dim again, and Claire squeezes his arm. The main film begins – 'This is the story of a ship' – with Coward as an improbably suave Royal Navy captain. There's a lot of clipped excitement. 'Vessel on fire bearing green three-oh… Torpedo track, starboard, sir… Carry on firing…' At the climax of the sea battle, Jericho looks around at the flickering of the celluloid explosions on the rapt faces, and it strikes him that he is a part of all this – a distant, vital part – and that nobody knows, nobody will ever know… After the final credits the loudspeakers play 'God Save the King and they all stand, many of the audience so moved by the film they begin to sing.

They've left their bicycles near the end of an alley running beside the cinema. A few paces further on a shape rubs itself against the wall. As they come closer they can see it is a soldier with his greatcoat wrapped around a girl. Her back is to the bricks. Her white face stares at them from the shadows like an animal in its hide. The movement stops for the time it takes Claire and Jericho to collect their bicycles, then it starts again.

'What very peculiar behaviour.'

He says it without thinking. To his surprise, Claire bursts out laughing.

'What's the matter?'

'Nothing, 'she says.

They stand on the pavement holding their bicycles, waiting for an Army lorry with dimmed headlights to pass, its gearbox grinding as it heads north along Watling Street. Her laughter stops.

'Do come and see my cottage, Tom.' She says it almost plaintively. 'It's not that late. I'd love to show it you.'

He can't think of an excuse, doesn 't want to think of one.

She leads the way through the town and out past the Park. They don't speak for fifteen minutes and he begins to wonder how far she's taking him. At last, when they're rattling down the path that leads to the cottage, she calls over her shoulder, Isn't it a perfect sweetheart?'

'It's, ah, off the beaten track.'

'Now don't be horrible, 'she says, pretending to be hurt.

She tells him how she found it standing derelict, how she charmed the farmer who owns it into letting her rent it. Inside, the furniture is shabby-grand, rescued from an aunt's house in Kensington that was shut up for the Blitz and never reopened.

The staircase creaks so alarmingly, Jericho wonders if their combined weight might pull it away from the wall. The place is a ruin, freezing cold. 'And this is where I sleep, 'she says, and he follows her into a room of pinks and creams, crammed full of pre-war silks and furs and feathers, like a large dressing-up box. A loose floorboard goes off like a gunshot beneath his feet. There's too much detail for the eye to register, so many hat boxes, shoe boxes, bits of jewellery, cosmetic bottles… She slips off her coat and lets it fall to the floor and flings herself flat out on the bed, then props herself up on her elbows and kicks off her shoes. She seems amused by something.

'And what's this?'Jericho, in a turmoil, has retreated to the landing and is staring at the only other door.

'Oh, that's Hester's room, 'she calls.

'Hester?'

'Some bureaucratic beast found out where I was and said if I had a second bedroom I had to share. So in came Hester. She works in Hut 6. She's a sweetie, really. Got a bit of a crush on me. Take a look. She won't mind.'

He knocks, there's no reply, he opens the door. Another tiny room, but this one spartan, like a cell: a brass bedstead, a jug and bowl on a washstand, some books piled on a chair. Ableman's German Primer. He opens it. 'Der Rhein ist etwas langer als die Elbe,' he reads. The Rhine is somewhat longer than the Elbe. He hears the gunshot of the floorboard behind him and Claire lifts the book from his hands.

'Don't snoop, darling. It's rude. Come on, let's make a fire and have a drink.'

Downstairs, he kneels by the hearth and rolls a copy of The Times into a ball. He piles on kindling and a couple of small logs, and lights the paper. The chimney draws voraciously, sucking up the smoke with a roar.

'Look at you, you haven't even taken off your coat.'

He stands, brushing the dust away, and turns to face her. Grey skirt, navy cashmere sweater, a single loop of milk-white pearls at her creamy throat – the ubiquitous, unchanging uniform of the upper-class Englishwoman. She somehow contrives to look both very young and very mature at the same time.

'Come here. Let me do it.'

She sets down the drinks and begins to unbutton his overcoat.

'Don't tell me, Tom,' she whispers, 'don't tell me you didn't know what they were doing behind that cinema?'

Even barefoot she is as tall as he is.

'Of course I knew…'

'In London nowadays the girls all call it a "wall job ". What do you think? They say you can't get pregnant this way…"

Instinctively, he draws his coat around her. She wraps her arms about his back.

Damn it, damn it, damn it.

He pitched himself forwards and out of the chair, sending the images scattering and smashing on the cold stone floor. He prowled around the tiny sitting room a couple of times, then went into the kitchen. Everything was clean and swept and put away. That would be Hester's handiwork, he guessed, not Claire's. The stove had burned down very low and was lukewarm to the touch, but he resisted the temptation to shovel in some coal. It was quarter to one. Where was she? He wandered back into the sitting room, hesitated at the foot of the stairs, and began to climb. The plaster on the walls was damp and flaking beneath his fingers. He decided to try Hester's room first. It was exactly as it had been six weeks earlier. A pair of sensible shoes beside the bed. A cupboard full of dark clothes. The same German primer. 'An seinen Ufern sind Berge, Felsen und malerische Schlosser aus den dltesten Zeiten.' On its shores are mountains, rocks and picturesque castles from the oldest times. He closed it and went back out on the landing.

And so, at last, to Claire's room. He was quite clear now about what he was going to do, even though conscience told him it was wrong and logic told him it was stupid. And, in principle, he agreed. Like any good boy he had learned his Aesop, knew that 'listeners never hear good of themselves' -but since when, he thought, as he began opening drawers, since when has that pious wisdom stopped anybody? A letter, a diary, a message – anything that might tell him why – he had to see it, he had to, even though the chances of its yielding any comfort were nil. Where was she? Was she with another man? Was she doing what all the girls in London, darling, call a wall job?

He was suddenly in a rage and he went through her room like a housebreaker, pulling out drawers and upending them, sweeping jewellery and trinkets off the shelves, pulling her clothes down on to the floor, throwing off her sheets and blankets and wrenching up her mattress, raising clouds of dust and scent and ostrich feathers.

After ten minutes he crawled into the corner and laid his head on a pile of silks and furs.

'You 're a wreck,' Skynner had said. 'You 're ruined.

You 've lost it. Find someone more suitable than the person you were seeing.'

Skynner knew about her, and Logie had seemed to know as well. What was it he'd called her? The 'arctic blonde'? Perhaps they all knew? Puck, Atwood, Baxter, everybody?

He had to get out, get away from the smell of her perfume and the sight of her clothes.

And it was that action that changed everything, for it was only when he stood on the landing, leaning with his back to the wall and his eyes closed, that he realised there was something he'd missed.

He walked back slowly and deliberately into her room. Silence. He stepped across the threshold and repeated the action. Silence again. He got down on his knees. One of auntie's Kensington rugs covered the floorboards, something oriental, stained, and tastefully threadbare. It was only about two yards square. He rolled it up and laid it on the bed. The wooden planks which had lain beneath it were bowed with age, worn smooth, fixed down by rust-coloured nails, untouched for two centuries – except in one place, where a shorter length of the old planking, perhaps, eighteen inches long, was secured by four very modern, very shiny screws. He slapped the floor in triumph.

'Is there any other point to which you would wish to draw my attention, Mr Jericho?'

'To the curious incident of the creaking floorboard.'

'But the floorboard didn't creak.'

'That was the curious incident.'

In the mess of her bedroom he could see no suitable tool. He went down into the kitchen and found a knife. It had a mother-of-pearl handle with an 'R' engraved on it. Perfect. He almost skipped across the sitting room. The tip of the knife slotted into the head of the screw and the thread turned easily, it came away like a dream. So did the other three. The floorboard lifted up to reveal the horsehair and plaster of the downstairs ceiling. The cavity was about six inches deep. He took off his overcoat and his jacket and rolled up his sleeve. He lay on his side and thrust his hand into the space. To begin with he brought out nothing except handfuls of debris, mostly lumps of old plaster and small pieces of brick, but he kept on working his way around until at last he gave a cry of delight as his hand touched paper.

He put everything back in its place, more or less. He hung the clothes back up from the beams, piled her underclothes and her scarves back into the drawers and replaced the drawers in the mahogany chest. He heaped the trinkets of jewellery into their leather case and draped others artfully along the shelves, together with her bottles and pots and packets, most of which were empty.

He did all this mechanically, an automaton.

He remade the bed, lifting off the rug and smoothing down the eiderdown, throwing the lace cover over it where it settled like a net. Then he sat on the edge of the mattress and surveyed the room. Not bad. Of course, once she began looking for things, then she would know someone had been through it, but at a casual glance it looked the same as before – apart, that is, from the hole in the floor. He didn't know yet what to do about that. It depended on whether or not he replaced the intercepts. He pulled them out from under the bed and examined them again.

There were four, on standard-size sheets, eight inches by ten. He held one up to the light. It was cheap wartime paper, the sort Bletchley used by the ton. He could practically see a petrified forest in its coarse yellow weave – the shadows of foliage and leaf-stalks, the faint outlines of bark and fern.

In the top left-hand corner of each signal was the frequency on which it had been transmitted – 12260 kilocycles per second – and in the top right its TOI, Time of Interception. The four had been sent in rapid succession on 4 March, just nine days earlier, at roughly twenty-five-minute intervals, beginning at 9.30 p.m. and ending just before midnight. Each consisted of a call sign – ADU – and then about two hundred five-letter groups. That in itself was an important clue. It meant, whatever else they were, they weren't naval: the Kriesgmarine's signals were transmitted in groups of four letters. So they were presumably German Army or Luftwaffe.

She must have stolen them from Hut 3.

The enormity of the implications hit Jericho for a second time, winding him like a punch in the stomach. He arranged the intercepts in sequence on her pillow and tried very hard, like a defending King's Counsel, to come up with some innocent explanation. A piece of silly mischief? It was possible. She had certainly never paid much attention to security – shouting about Hut 8 in the station buffet, demanding to know what he did, trying to tell him what she did. A dare? Again, possible. She was capable of anything. But that hole in the floorboards, the cool deliberation of it, drew his gaze and mocked his advocacy.

A sound, a footstep downstairs, dragged him out of his reverie and made him jump to his feet.

He said, 'Hello?' in a loud voice that suggested more courage than he felt. He cleared his throat. 'Hello?' he repeated. And then he heard another nose, definitely a footstep, and definitely outside now, and a charge of adrenaline snapped in. He moved quickly to the bedroom door and turned the light off, so that the only illumination in the cottage came from the sitting room. Now, if anyone came up the stairs, he would be able to see their silhouette, while remaining hidden. But nothing happened. Perhaps they were trying to come round the back? He felt horribly vulnerable. He moved cautiously down the stairs, flinching at every creak. A blast of cold air struck him.

The front door was wide open.

He threw himself down the last half-dozen steps and ran outside, just in time to see the red rear light of a bicycle shoot out of the track and vanish down the lane.

He set off in pursuit but gave up after twenty paces. He didn't stand a chance of catching the cyclist.

There was a heavy frost. In every direction the ground shone a dull and luminous blue. The branches of the bare trees were raised against the sky like blood vessels. In the glittering ice, two sets of tyre-tracks were imprinted: incoming and outgoing. He followed them back to the door, where they ended in a series of sharp footprints.

Sharp, large, male footprints.

Jericho looked at them for half a minute, shivering in his shirtsleeves. An owl shrieked in the nearby copse and it seemed to him that its call had the rhythm of Morse: dee-dee-dee-dah, dee-dee-dee-dah.

He hurried back into the cottage.

Upstairs, he rolled the intercepts very tightly into a cylinder. He used his teeth to tear a small hole in the lining of his overcoat and pushed the signals into it. Then he quickly screwed down the floorboards and replaced the rug. He put on his jacket and coat, turned off the lights, locked the door, replaced the key.

His bicycle added a third set of impressions in the frost.

At the entrance to the lane he stopped and looked back at the darkened cottage. He had a strong sensation – foolish, he told himself- that he was being watched. He glanced around. A gust of wind stirred in the trees; in the blackthorn hedge beside him, icicles clinked and chimed.

Jericho shivered again, remounted the bike and pointed it down the hill, towards the south, towards Orion and Procyon, and to Hydra, which hung suspended in the night sky above Bletchley Park like a knife.