He had become a creature of habit, he knew it well. The car turned in preparation for the next call. The last look out at the street before double locking the front door. The briefcase repacked, then left by the table where the telephone sat, hat and coat hung up opposite. Sometimes he went in search of a long postponed supper, footsteps soaking into the kitchen linoleum while he found bread and ham or cheese, hovering to eat rather than sitting alone at the table. Returning to the hall, a tap of the barometer, an instinct, no real interest in the fluctuations of pressure swirling around him, then lights were switched off and the way made up the stairs in darkness, unconsciously avoiding one step's creak, another's unevenness. The same type of tea and brand of toothpaste. The same make of cigarettes. These were the fixed points around which explosions of unpredictability made their riot, certain routines when all else slid away. Patrick did not know whether it was he who clung to them, or they him, gripping him in a hold so firm he wondered if it was too strong now to loosen.

He knew that changes, more seismic than shifting furniture or altering words on legal documents, must be made. The balance of his life, obligations he allowed to devour his time and good-humour, frequently wracked him with guilt; yet they were easy to justify when the only one who challenged him was no equal partner but a child. To share his life was to uncurl the fist in which he held the reins, offering them once again to a wife, accepting he was accountable to her as she was to him. He had borne the strain alone so long he was desperate to feel the burden eased. After so long, however, he could not guess where the changes must be made which would let her hand clear the mess from his paths, suggesting routes they should follow. In the autumn one wild, impulsive burst of certainty had made him briefly abandon the call of duty to answer the quiet clamour of love. No second burst appeared now to show him what to alter and what to keep as they crossed into the new life. While the dull routines seemed to shake before a silent, gentle earthquake, which walls should tumble he could not tell.

He had adapted before, Patrick reflected as he arrived at the upstairs landing. But then the changes had been enforced and he had gradually absorbed each new responsibility laid upon him. How strangely difficult it was to let the pressure be relieved when those rituals now disciplined his days; they gave him order. In one case, the last and sweetest of the day, it brought him joy. It was this to which he turned now, quietly opening Timothy's bedroom door. Immersed in his thoughts, he did not notice the glimmers of light peeking from the bottom.

By the light of the bedside lamp, Timothy was poring intensely over a book in such fierce concentration that by the time he was caught it was far too late for any flurry of bedclothes and pretence he was asleep. Instead he faced his father.

"Timothy! It's past eleven! What are you doing up? You know when bedtime is. I trust you to keep to it." His voice was harsher than intended. At first he only saw Timothy's guilty face, then, as the boy did not reply, he took in the drawn expression, the circles spreading under his swollen eyes and finally the battered bear, plucked from long abandonment and familiarly propped against the pillow. "Are you not feeling well? Did something happen at school?"

Timothy shook his head. "No. School was alright. A bit boring."

"Is it the pantomime? Are you feeling nervous? You'll be great."

"No. It'll be OK," he mumbled. He looked at his bedspread, swallowing and fiddling with the edges of the book. Patrick recognised the gestures; he felt them in his own throat and fingers often enough.

Drawing up the chair from behind Timothy's desk, he sat down by the edge of the bed, hands leant against his knees, his voice gentler. "Could you not sleep?"

"No," said Timothy unhappily. His voice was troubled. "I did try, Dad, I really did. Promise. I switched my light off at the right time and everything. But I couldn't sleep so I put it back on again."

"Were you reading to help you drop off? I do that as well."

"Sort of," said Timothy, squirming, hoping his father would speak again. But he did not. Patrick waited, listening to the stretching silence until Timothy continued. "I was checking something."

"What are you reading?" Sitting up, Timothy handed over the book. Patrick looked down and frowned. "Checking something in this?" It was The Silver Sword. He had been uneasy when David and Louisa gave it to Timothy for Christmas the previous year, although they reassured him: it was beautifully written, its account of the war balanced. Alex apparently had loved it. He had read it along with Timothy as far as he could, although the era of bedtime stories was past and his presence at the end of the day irregular, sometimes reading to him, more frequently listening to Timothy read to him. At other times he read on himself, initially to see where the narrative went, later out of interest in characters who had inveigled their way into his affections; and he had accepted that David and Louisa were right. What Timothy might want to clarify he could not imagine however, even though the story was based on fact. "What on earth did you want to check?"

"The bit at the start when the dad's in the prison camp." He faltered. "I wanted to see what it was like in one." And the book had told him: freezing, starving, lonely, miserable and cruel.

"And why did you suddenly want to know about that?"

While the letter from Dr. Stewart was innocuously hidden under a sketch book in his drawer, in Timothy's mind it burned. "I was reading something today and it made me think about how war camps would be really horrible." He had not meant to ask, but while his father paused, considering how to reply, a question strained from Timothy. "Dad?"

"Yes, son?"

"In the war, were you ever scared you might have to go to a camp?"

He had ten minutes before he must be back. He could not remember when he had last had more than fifteen minutes of respite. Underneath the stench of blood and burning and his own foul sweat, he could catch salt in the air, although he wondered if his memory was mocking him with recollections of childhood. He and Michael had run along beaches, shrieking. Now the shrieks were agonised and spattered with mechanical howls, incessant chords of moaning. The day had been so dull he barely noticed what colour there had been leeching from it. Lighting up, he stared at the absence on the blank horizon. Behind him was another horizon, also bleak and filthy, from which something else was steadily coming, more certain than more boats somewhere on the churning water. He saw its phantasm every moment he looked back, that vast cold machine against which they were boys with wooden bows and arrows; relentless, faceless, rolling with fire; and then as the smoke shifted, it vanished. How long until it arrived and they were lost? How long?

"You tried not to think about it," Patrick replied, as slow as he was evasive.

"You must've at Dunkirk," Timothy began, stopping when he heard his father's quick suck of breath.

The voice was neither hasty nor angry, only very still. "How do you know about that?"

"You told me," said Timothy. "Sort of. You remember ages ago when I found your war medals and you told me to stop playing with them?" Patrick nodded. "I asked Mum where you'd been and she told me. Or maybe it was Grandpa Parker, I can't remember. Anyway, one of them told me, except I forgot except it started with 'D' so I asked Uncle David." He could not read his father's face; it was kind, but guarded. "I knew before. He just reminded me so I could get my facts straight."

"I see."

Leaning forward, Timothy watched his father as intensely as he had scrutinised the book. "Was it really scary when you were waiting?"

"You don't want to know about that," he muttered.

"Yes, I do," cried Timothy bitterly. "You always say things like that and you never answer properly!"

He sounded angry, although Patrick knew it was not anger. For a second he saw the boy's face, fraught with exhausted unhappiness. Then Timothy turned away, his sudden movement dislodging the bear until it slipped on its side. More than the words or the face, it was this that moved Patrick: the elderly, porridge coloured toy, its shapeless left side almost bald from 'cuddle wear' and its eyes mismatched, returned to for comfort by one for whom it was now far too childish.

Those horrors he tried to smother. He did not want to dredge them up. Yet, laying the book on the bedside table with a sigh, he got up. "Alright. Budge over, Timothy."

Timothy's mouth opened into the tiniest smile as he shuffled into a corner, waiting until Patrick sat down, on top of the bedclothes but next to him, before wriggling within his cocoon of sheets and curling within his father's arm. "We haven't done this for a fair old while, have we?" said Patrick.

It had been many, many months, before the seductive oblivion of work had lured Patrick, offering him its way to bury his sorrow, rather than share and heal it. Both knew it.

"Mum would tell you off for having your shoes on the bedspread," observed Timothy.

"What Mum doesn't know won't hurt her," said Patrick. The remark was instinct, a line evoking a dozen silly reminiscences from when their lives had seemed blessed – a football illicitly played with inside which nearly broke a favourite vase, shoe polish which ended up on the carpet, extra biscuits snaffled – without thinking how much it still might hurt. Anxiously, he looked down.

Timothy was giggling. "I think Shelagh'd tell you off too," he grinned.

Grin answered grin. "Probably." Using one foot to ease off the shoe on the other, he flicked his shoes to the floor without undoing the laces. "What she doesn't know won't hurt her either," he added. "Now," he said, sober again, "what do you want to know?"

Timothy's tangle of anxiety was filled with the questions he had asked Sister Julienne and Peter Noakes. They rose again like giant fish, seeking answers from his father, not for him. "When you were waiting for the boats to come, did you think you'd be captured?"

Patrick moistened his lips. "I knew it might happen, yes. And we were evacuated quite near the end so the chance was a tiny bit higher." It had been the penultimate night, leaving the French behind, some to be rescued the following night, the depleted rest left to face what came. Once he had counted the hours by which he had escaped, then tried to erase the thought from his memory.

"Was it scary?"

The truth was as simple as the question. "Yes. It was scary."

Under his arm Timothy's head nestled against Patrick's collar bone, waiting for stronger reassurance to tighten around him before he dared the next question. "Did you think you would die?"

Years ago Patrick had often held the boy like this, smoothing back his hair with quiet shushing while Timothy shuddered, his father's hand on his skull the protection from monsters which terrified his dreams. He almost expected to inhale the same baby scent or feel the fluffy tufts of soft hair, not the coarser strands which each year grew closer in shade to his own. "Sometimes. Very, very occasionally. I wasn't in the most dangerous place though, Timothy. Not like Uncle Michael in the front line. I promise."

"How did you stop being scared?"

Timothy could not see Patrick fleetingly raise his eyebrows. "I don't think I did. But there were lots of men to treat and I just had to get on with it. It was my duty." It felt trite to speak of duty, yet it had been how he endured, retaining something of himself amidst suffocation. "Sometimes, when you've got lots of work you forget about difficult things for a while and that helps you keep going. Like you having school when Mum was ill, remember? We really did try not to think about it, Timothy, not until we had to and if we had to." Hearing Timothy snuffle beside him, Patrick gave him a gentle squeeze. "In the end it was all alright, wasn't it?"

"I suppose," said Timothy in a muffled voice. "It would be awful being a prisoner. The worse thing in the world!"

"Really?" Perhaps the end of liberty was the worst of all possible punishments for an active boy. He had dreaded the prospect, appalled by the thought of restrictions ten times more draconian than the military discipline which irked him. But the war had taught him greater wisdom in its dusty moral hinterlands. "I think there are far worse things." Timothy shifted to look up at him, the unspoken question entirely clear. "Worse even than dying I think."

"Dad?"

"Yes, son."

"Did you have to shoot anyone in the war?" He had not understood the end of Dr. Stewart's letter at first, what repulsive things might have had to be done, and though he had puzzled at it, the earlier, clearer account of his father's sacrifice had gripped Timothy's imagination more. Now the strange expression on his father's face made him recall another moment from his storybook, where the father hit a man with a stone until he did not move; and that father too was a good and loving man.

Patrick twitched. "It's difficult not to in a war."

Timothy eyed him. "Did you ever kill anyone, Dad?" Watching the colour shift in Patrick's face, Timothy knew instantly that he was right. His eyes started to glisten with fantasies of courage under fire. "Was it a German? It's OK if you killed a German! That's being a hero."

"Don't say that, Timothy. Don't." He had long suspected the direction in which the foul wind of the thirties was blowing, perhaps from the day Ben Adelman began working at his hospital, barely masking his conflicting sorrow and relief at fleeing his home in Heidelberg and accepting the casual suspicion of patients and colleagues with quiet, constant anxiety. As Patrick watched the newsreels of the baying mob at Nuremberg and read the reports of vile, demented speeches, it baffled, then revolted him; he had had no hesitation in joining up. Even in the midst of the war however, when he dreamed of the enemy it was not the persecuting hoard he envisaged: it was another young doctor, from Berlin or Frankfurt perhaps, toiling in a field hospital. He had the accent and manner of Ben Adelman and was strengthened by memories of student nights in beer gardens with friends before their lives were cast into limbo. "You mustn't say that."

"It was a German though?" Mute, Patrick shook his head. Subdued but curious, Timothy tried to remember the other combatants, wars and enemies muddling together. "Was it a Russian?"

"No. That was a different bit of the war," said Patrick.

"Who then? Were you fighting in a battle?"

He had heard the shout, "Doc! Sir! My mate, come and look at him, doc." and followed the sound. Blood drenched the front of the uniform, a stain of it seeping into the sand. He had been carried as gently as it could be without a stretcher until he started to fit and bubble, then set down and a doctor desperately sought to come to him, if he could not be taken to a doctor. He knew it was impossible even before raising the flap of cloth covering the shattered entrails, watching them burst from the abdomen into uncoiling anarchy, oozing with blood and blasted spongy flesh. There was no edge to the wound; it was jagged and cavernous, seemingly endless, spreading down towards the colon and above the perforated stomach.

"Can you help him, doc? Please, doc."

"No. It was at Dunkirk, before the boats arrived."

Timothy trembled. "I thought you got away before the Germans came."

"I did. We did." There were probably fewer than a dozen people who knew the story, he supposed. Only Kenneth and Elizabeth had heard from him; not even David, although twice he had come close. From a hospital bed, memories of Trondheim scarring him more than his injuries, Kenneth had reassured him. Elizabeth had loved him still: in those days of black and white survival the thought that one's beloved had killed was normal. It was so long ago that until tonight it had not occurred to him to tell Shelagh. It troubled him imagining how this might stain and botch him in her eyes, although he knew how deeply she understood human suffering; she saw it constantly and he had never known her to judge. But Timothy, who saw the war as a series of simple truths and acts of courage, so quick to leap to verdicts, what of him? "He wasn't an enemy soldier, Timothy. He was a patient." As the dark eyes widened in wary comprehension, Patrick added the final truth. "Another Englishman."

Timothy shivered. But in the next second, as certainly as he had felt the sudden cold, he knew his security was still his father's arm. His fingers contracted, clutching the woollen waistcoat. "Why?"

"He was very sick, Timothy."

"What was wrong with him?"

The guts were an obscene mess. More ghastly was the grotesque face, its froth of blood dribbling from the mouth. Had he been able to make the sound he would have screamed. For an instance the eyeballs ceased their rolling and fixed upon Patrick and they were pleading.

"He had been nearby when there was an explosion and he got injured in his tummy. Inside your tummy there's an organ called the intestine - "

"The big wriggly worm. You told me all about when Simon had his appendix taken out."

"Did I? Well remembered. Yes, it's like a big wriggly worm. So, his intestine had been damaged in a lot of places. If somebody got injured like that now, you'd rush him to hospital immediately and a very clever surgeon like Uncle Kenneth could maybe make him better. But we didn't have anyone like Uncle Kenneth around and it had taken time to get him to us so we couldn't make him better."

It was a vicious miracle he was still alive. He choked on the water he was offered.

"Was he hurting a lot?"

"Yes. He was in terrible pain. And when it's that bad, you want to stop people hurting. Do you remember near the end when Mum was ill how Sister Julienne used to visit and give her injections every morning and evening?"

"Yes. It made Mummy sleepy all the time so we couldn't talk to her properly."

"Yes, that's right. The injections stopped Mum being in pain and meant she wasn't suffering so much. So Sister Julienne was helping her, wasn't she, by stopping her being in pain?"

"Yes. Do you not know how to give those injections, so you couldn't give them to that soldier and Sister Julienne had to give them to Mum?" he asked innocently.

"No," said Patrick. "I know how to administer them. With Mum, it was just better Sister Julienne did it. " He stumbled momentarily. "At Dunkirk, I didn't have enough of the drug. We didn't know how long we would have to wait for the boats and we were running out of supplies." Prioritise morphine for those who'll live, they were commanded. There were more supplies further down the beach they thought, although in the chaos nobody knew for sure. But he could not walk away from such abject misery. The guttural moaning, the wretchedness flickering in and out of the distorted features. The friend had known, tearing his hair and unleashing an incoherent string of profanities. Encircling the man's shoulder to raise his head, gorge rising, he felt for his service revolver. It was cold within his shaking hand. He was only bringing forward what would come, his tableau one insignificant spot within the canvas. In his head was the rumble of pandemonium. The body gulped and bubbled again. As he placed the gun against the temple, something in his peripheral vision shifted.

"What did you do?"

He was shaking again when he looked up, feeling the splattering of warm tissue dripping on his hands and face. Major Stewart was in front of him, watching with infinite compassion.

"This is what we became doctors for?"

"Yes, Captain," replied Major Stewart. "To stop suffering. What else? Report back in fifteen minutes."

He stumbled to his feet. "I'm fine."

"Turner!" His voice was low and warm. "Report back in fifteen minutes."

Patrick bowed his head in acknowledgment; he was not sure of what. "Sir." As Major Stewart walked away, briefly his hand closed on Patrick's shoulder.

"I shot him."

Timothy was nuzzling into his chest."What was he called? Do you know?"

"Oh yes, I couldn't forget," said Patrick quietly. The tiny movement which brought Timothy closer flooded him with relief. He had been terrified his son would recoil. "Private Patrick Webb." He heard Timothy's breath catch. "Yes. His friends called him Spider, but his name was Patrick, like me."

They played at war at lunchtimes, mimicking the sounds of guns and Spitfires, giggling if they were killed and basking in temporary glory when they were the victors. They swapped exaggerated stories of their fathers' service. Timothy had hoped for a simple story as the missing chapter of his father's life, a tale like Laura Barrett's, who bragged of the men her father had killed in North Africa. Instead he found an intricate maze of complex decisions, littered with human flesh. Yet standing in the middle of the maze of the past was no unknown hero who killed or maimed with ease, only his father, still Dad, still holding to the same unshaken values: to work, to give, to endure. His final discovery, after all his plots and dreaming, was the man he had always known. "Dad?"

"Yes?"

"I think that was brave."

"Do you? Really?"

"Yes. It's brave in a different way. It's OK." Above Timothy's head, Patrick's eyes closed as he lent down and kissed the top of the boy's head. "Dad? There's not going to be another war, is there?"

"Not like the last time, not like that." There might be another, the dreadfulness of which he could not contemplate. Sometimes he looked at Timothy and wondered what hostage to fortune he and Elizabeth had brought into the world. When he imagined another child, staring with its mother's mild blue eyes, occasionally the dream blackened into nightmare, befouled by an evil which leered at the peace which had cost so much to create. But such a war would take them all and take them together in one great stark flash of desolation. It would not take his boy, as the last one had taken him and Michael and the one before their father. "I won't let them take you.

"Do you think you can get to sleep now? Big week coming up and everything."

"Yeah. Think so." As Patrick swung his legs over the side and stood up, Timothy twisted into the middle of his bed. "I'm sorry you had to come in to tell me off."

Patrick laughed. "I didn't come in to tell you off. I hadn't realised your light was on." He smiled at Timothy's confusion. "I came in to say good night. I always pop in and check on you. It's the last thing I do before getting ready for bed."

"Every day? Even when I'm asleep?"

"Yes, of course. Usually you are asleep, thankfully!"

"Even if it's two o'clock in the morning?"

"Even if it's four o'clock in the morning. Last round of the day."

"Have you always done it? Ever since I was really little?"

"Mostly. When you were a baby I always checked, just to see you were alright." A strange amalgam had drawn him each night: the doctor marvelled at the baby's healthy completeness, the father cheerfully worshipped. "You always made me feel a bit better about the world and even when you weren't sleeping you were such fun." A gleeful smile, potent with mischief, used to greet him from the bouncing toddler, resolutely standing in his cot in anticipation of fun. He still remembered; at times the smile had hardly changed. "Little monster. As you got a bit older, I didn't always pop in if I'd been out on calls very, very late, but I started again a while ago."

"After Mum died?" asked Timothy shrewdly.

"Before that. After she became ill." Now he doubted he could sleep at all without the ritual.

"Dad, how come when I was little I was fun if I didn't go to sleep, but now it's annoying?"

"Because life's unfair. Go to sleep." Patrick switched off the lamp.

As the light dissipated, Timothy's giggle flickered away. "Dad?" he mumbled.

"Yes?"

"Will you stay for a bit?"

With the only light coming from the curtained window, Timothy could not clearly see Patrick nod. He heard the scrape of the chair, however, as Patrick sat down once again next to his bed. "Alright, if you want me to. Go to sleep. I'll stay here until you have." And although he dozed within the chair, his eyes occasionally closing, it was only when Timothy's breathing steadied into the slow, restful rhythm of one who was not dreaming of camps or death that Patrick left his side.