I do not remember much about the days immediately following my father's disappearance, other than that I was often so concerned about Akira – in particular, what I would say when I next saw him – that I could not settle to anything. Nevertheless I found myself continually putting off a visit next door, even contemplating for a while the notion that I might never need face him at all – that his parents, so angered by our misdemeanour, were even at that moment packing their bags for Japan. During these days any sort of loud noise outside would send me rushing upstairs to the front windows, from where I could scrutinise the next-door courtyard for signs of piling luggage.

Then after three or four days had passed, on an overcast morning, I was playing by myself out on the circle of lawn in front of our house when I became conscious of the sounds coming from Akira's side of the fence. I quickly realised that Akira was moving about on his sister's bicycle around his carriage track; I had often enough watched him trying to ride this bicycle, which was far too large for him, and recognised the scraping noises the wheels made as he struggled for balance. At one stage I heard a crash and a yell as he fell off altogether. The possibility occurred to me that Akira had spotted me out playing from his upstairs window and had come out with the bicycle expressly to attract my attention. After several further moments of hesitation – during which Akira continued to crash about on his side – I finally strode out of our gateway, turned and stared into his front garden.

Akira was indeed astride Etsuko's bicycle, absorbed in attempts to execute some circus-like manoeuvre that required taking his hands from the handlebar just as he turned a tight circle. He appeared too absorbed to notice me, and even when I walked up to him, gave no sign of having seen me. Finally I said simply:

‘I'm sorry I couldn't come the other day.’

Akira gave me a sulky glance, then went back to his manoeuvres. I was about to give him my explanation for having let him down, but for some reason, found I could say nothing more. I stood there watching him for a little longer. Then taking a further step towards him, I said, lowering my voice to a whisper:

‘What happened? Did you put it back?’

My friend gave me a glare that rejected the intimacy implied by my tone, then spun his bicycle round. I felt tears coming, but remembering in time our long-standing feud about whether the English or Japanese cried easiest, I managed to stifle them. I thought again of telling him about my father's disappearance, and suddenly it seemed a hugely substantial reason not only for my having let him down, but for great self-pity on my part. I pictured the shock and shame that would transform Akira's face once I uttered the words: ‘I couldn't come the other day because … because my father's been kidnapped!’ – but somehow I could not say it. Instead, I believe I simply turned and ran back to my house.

I did not see Akira for the next few days. Then one afternoon he came to our back door, asking Mei Li for me as usual. I was in the middle of something, but dropped it all and went out to my friend. He greeted me smilingly, and as he led me away to his garden, patted me affectionately on the back. I was of course anxious to discover just what had transpired over the Ling Tien matter, but being even more keen not to re-open wounds, resisted the urge to ask anything about it.

We went to the back of his garden – to the thick shrubs we called our ‘jungle’ – and soon became immersed in one of our dramatic narratives. I have a feeling we acted out scenes from Ivanhoe, which I was reading at that time – or perhaps it was one of Akira's Japanese samurai adventures. In any case, after an hour or so, my friend suddenly stopped and looked oddly at me. Then he said:

‘If you like, we play new game.’

‘A new game?’

‘New game. About Christopher father. If you like.’

I was taken aback and I do not recall what I said next. He came a few steps closer in the long grass and I saw he was looking at me almost tenderly.

‘Yes,’ he said. ‘If you like, we play detective. We search for father. We rescue father.’

I then realised that it was hearing the news about my father – which no doubt had started to do the rounds of the neighbourhood – that had brought Akira back to my door. I understood too that this present proposal was his way of showing his concern and wish to help, and I felt my affection for him welling up. But in the end, I said quite nonchalantly:

‘All right. If you want to play that, we can.’

And that was how it began, what today in my memory feels like an entire era – though in truth it could only have been a period of two months or less – when day after day we invented and played out endless variations on the theme of my father's rescue.

Meanwhile the real investigations into my father's disappearance were continuing. I knew this from the visits we received from the men who held their hats in their hands and talked solemnly to my mother; from the hushed exchanges between my mother and Mei Li when my mother came in, tight-lipped, at the end of an afternoon; and in particular, there was that conversation I had with her at the foot of the staircase.

I have no real memory of what either of us had been doing prior to that moment. I had started to run up the stairs, eager to fetch something from the playroom, when I realised my mother had appeared at the top and was making her way down. She must have been about to go out, for she had on her special beige dress, the one that gave off a peculiar smell like mouldering leaves. I suppose I must have sensed something in her manner, for I stopped where I was on the third or fourth step and waited for her. As she came towards me, she smiled and reached out a hand. She did this while still a number of steps above me, so that I thought for a moment she was wishing me to assist her down the rest of the stairs, the way my father sometimes did when he waited for her at the foot of the staircase. But as it turned out, she simply put her arm around my shoulder and we descended the last steps together. Then she let go of me and walked over towards the hat-stand on the other side of the hall. It was as she did so that she said:

‘Puffin, I know how difficult these last few days have been for you. It must seem as though the whole world's caving in. Well, it's been difficult for me too. But you must do as I have. You must keep praying to God and remain hopeful. I hope you are remembering your prayers, aren't you, Puffin?’

‘Yes, I am,’ I replied, rather off-handedly.

‘It's a sad fact,’ she went on, ‘that in a city like this, from time to time, people do get kidnapped. In fact it happens rather often, and a lot of the time, I'd go so far as to say most of the time, the people come back perfectly safely. So we have to be patient. Puffin, are you listening to me?’

‘Of course I'm listening.’ I had by this time turned my back to her and was dangling by my arms from the banister post.

‘What we have to appreciate,’ my mother said after a pause, ‘is that the city's very best detectives have been assigned to the case. I've spoken with them, and they're very optimistic a solution will be found soon.’

‘But how long will that be?’ I asked sullenly.

‘We have to be hopeful. We have to trust the detectives. And it may take a little time, but we must be patient. Then in the end things may well come right, and everything will be just as it was before. We must continue to pray to God and always keep hopeful. Puffin, what are you doing? Did you hear me?’

I did not respond immediately, because I was trying to see how many steps my feet could climb while I continued to cling to the banister post. Then I asked:

‘But what if the detectives are too busy? With all the other things they have to solve? Murders and robberies. They can't do everything.’

I could hear my mother coming back a few steps towards me, and when she next spoke, a careful, deliberate tone had entered her voice.

‘Puffin, there is no question whatsoever of the detectives being “too busy”. Everyone in Shanghai, the most important people in this community are extremely anxious about Father, and very concerned to have the matter cleared up. I mean gentlemen like Mr Forester. And Mr Carmichael. Even the consul-general himself. I know they've made it their personal concern to see Father return safely as soon as possible. So you see, Puffin, there is no chance at all of the detectives giving anything but their utmost. And that's what they're doing, now, at this very moment. Do you realise, Puffin, Inspector Kung himself has been put in charge of this investigation? Yes, that's right: Inspector Kung. So you see, we've every reason to be hopeful.’

This exchange undoubtedly made some impact, for I remember I did not worry nearly so much during the following several days. Even at nights, when my anxieties tended to return, I would often go to sleep thinking of Shanghai's detectives moving all around the city, closing in ever more tightly on the kidnappers. Sometimes, lying in the dark, I found myself weaving quite elaborate dramas before dropping off to sleep, many of which would then serve as material for Akira and me the next day.

I do not mean to imply, incidentally, that during this period Akira and I did not play games quite unconnected with my father; sometimes we could lose ourselves for hours in one of our more traditional fantasies. But whenever my friend sensed I was preoccupied, or that my heart was not in what we were doing, he would say: ‘Old chap. We play father rescue game.’

Our narratives concerning my father had, as I say, endless variations, but fairly quickly we established a basic recurring story-line. My father was held captive in a house somewhere beyond the Settlement boundaries. His captors were a gang intent on extorting a huge ransom. Many smaller details evolved quite rapidly until they too became fixtures. It was always the case, for instance, that despite being surrounded by the horrors of the Chinese district, the house in which my father was held was comfortable and clean. In fact, I can still remember how this particular convention came to be established. It was perhaps our second or third time of trying the game, and Akira and I had been taking it in turns to play the role of the legendary Inspector Kung – whose handsome features and dandily worn hat we both knew well from newspaper photographs. We had been quite absorbed in the excitements of our fantasy, when suddenly, at the point when my father first appeared in our story, Akira gestured to me – indicating that I should play him – and said: ‘You tied up in chair.’

We had been in full flow but now I stopped.

‘No,’ I said. ‘My father isn't tied up. How can he be tied up all the time?’

Akira, who never liked to be contradicted when unfolding a narrative, repeated impatiently that my father was tied up in a chair and that I should mimic this at the foot of a tree without further delay. I shouted back: ‘No!’ and stalked off. I did not, however, leave Akira's garden. I remember standing at the spot where his lawn started – where our ‘jungle’ ended – and staring blankly at a lizard climbing the trunk of an elm. After a moment I heard Akira's footsteps behind me and braced myself for a full-blown argument. But to my surprise, when I turned to him, I saw my friend gazing at me with a conciliatory look. He came closer and said gently:

‘You right. Father not tied up. He very comfortable. Kidnappers’ house comfortable. Very comfortable.’

After this it was always Akira who took great care to ensure my father's comfort and dignity in all our dramas. The kidnappers always addressed him as though they were his servants, bringing him food, drink and newspapers as soon as he requested them. Accordingly the characters of the kidnappers softened; it turned out they were not evil after all, simply men with starving families. They truly regretted having to take such drastic action, they would explain to my father, but they could not bear to see their children starve to death. What they were doing was wrong, they knew it, but what else were they to do? They had chosen Mr Banks precisely because his kind views towards the plight of the poorer Chinese were well known, and he was likely to understand the inconvenience to which they were putting him. To this, my father – whom I always represented – would sigh sympathetically, but then go on to say that whatever the hardships of life, crime could not be condoned. Besides, inevitably, Inspector Kung would sooner or later come with his men to arrest them, then they would be thrown into prison, perhaps executed. Where would that leave their families? The kidnappers – represented by Akira – would respond by saying that once the police discovered their hideout, they would give themselves up quietly, and wish Mr Banks well as he rejoined his family. But until then, they were obliged to do their utmost to make their scheme work. They would then ask my father what he required for his dinner, and I would order on his behalf a vast meal of his favourite dishes – roast sirloin, buttered parsnips and poached haddock always among them. As I say, it was Akira rather than myself who tended to be the more insistent on these luxurious aspects, and it was he who added many of the other small but important details: my father's room would have a fine view over the rooftops to the river; the bed would be one his captors had stolen for him from the Palace Hotel, and thus the ultimate in comfort. In time, Akira and I would become the detectives – though sometimes we played ourselves – until in the end, after the chases, fist-fights and gun-battles around the warren-like alleys of the Chinese districts, whatever our variations and elaborations, our narratives would always conclude with a magnificent ceremony held in Jessfield Park, a ceremony that would see us, one after the other, step out on to a specially erected stage – my mother, my father, Akira, Inspector Kung and I – to greet the vast cheering crowds. This was, as I say, our basic story-line, and I suppose, incidentally, it was more or less the one I enacted over and over during those first drizzly days in England, when I filled my empty hours wandering about the ferns near my aunt's cottage, muttering Akira's lines for him under my breath.

It was not until perhaps a month after my father's disappearance that I finally found the nerve to ask Akira what had happened about Ling Tien's bottle. We had been taking a moment's break from our playing, sitting together in the shade of the maple at the top of our mound, drinking the iced water Mei Li had brought out to us in two tea-bowls. To my relief Akira no longer showed any sign of bitterness.

‘Etsuko take back bottle,’ he said.

His sister had initially been most obliging. But now, whenever she wanted to force Akira to do something, she would threaten to reveal his secret to their parents. Akira though was not unduly troubled by this ploy.

‘She go to room too. So she just as bad as me. She not tell.’

‘So there wasn't any trouble,’ I said.

‘No trouble, old chap.’

‘So you won't have to go and live in Japan.’

‘No Japan.’ He turned to me and smiled. ‘I stay Shanghai for ever.’ Then he looked at me solemnly and asked: ‘If father not found. You must go England?’

This startling notion for some reason had never before occurred to me. I thought it over, then said:

‘No. Even if Father isn't found, we'll live here for ever. Mother will never want to go back to England. Besides, Mei Li wouldn't want to go. She's a Chinese.’

For a moment, Akira went on thinking, staring at the icecubes floating in his bowl. Then he looked up at me and beamed broadly.

‘Old chap!’ he said. ‘We live here together, always!’

‘That's right,’ I said. ‘We'll live in Shanghai for ever.’

‘Old chap! Always!’

There was one other small incident from those weeks following my father's disappearance which I have now come to believe highly significant. I did not always regard it so; in fact, I had more or less forgotten it altogether when a few years ago, quite by chance, something happened which caused me not only to recall it again, but to appreciate for the first time the deeper implications of what I had witnessed that day.

It was during the period shortly after the Mannering case, when I was undertaking some research into the background of those years I spent in Shanghai. I believe I have mentioned this research before, much of which I conducted in the British Museum. I suppose it was, at least in part, my attempt as an adult to grasp the nature of those forces which as a child I could not have had the chance of comprehending. It was also my intention to prepare my ground for the day I began in earnest my investigations into the whole affair concerning my parents – which despite the continuing efforts of the Shanghai police has remained unresolved to this day. It remains, incidentally, my intention to embark on such an investigation in the not-too-distant future. In fact, I am sure I would have done so already had the demands on my time not been so relentless.

In any case, as I say, I spent a good many hours in the British Museum a few years ago gathering material on the history of the opium trade in China, on the affairs of Morganbrook and Byatt, on the complex political situation in Shanghai at that time. I did also, at various points, write off letters to China seeking information unavailable to me in London. So it was that I received one day a yellowed cutting taken from the North China Daily News dated some three years after my departure from Shanghai. My correspondent had sent me an article about changes to trading regulations in the concession ports – which no doubt I had requested – but it was the photograph which happened to be on the reverse side that immediately captured my attention.

I have kept that old newspaper photograph in the drawer of my desk, inside a tin cigar box, and from time to time I take it out and stare at it. It shows three men in a leafy avenue, standing in front of a grand motor car. All three are Chinese. The two on the outside are wearing Western suits with stiff collars, and hold bowler hats and canes. The plump man in the centre is in traditional Chinese dress: a dark gown, cap and pigtail. As with most newspaper photographs of the time, there is a stagy, posed feeling to it, and my correspondent's scissors have cut off perhaps an entire quarter of it to the left. Nevertheless, from the moment my glance first fell on it, the picture – more precisely, the central figure in the dark gown – has been a source of exceptional interest to me.

Alongside this photograph, in my tin cigar box in the drawer, I keep the letter I received from the same correspondent a month or so afterwards in reply to further enquiries. In it, he informs me that the plump man in the gown and cap is Wang Ku, a warlord who at the time of the photograph wielded much power in the Hunan province, employing a motley army of almost three hundred men. Like most of his sort, he lost much of his power after the ascendancy of Chiang Kai-shek, but was rumoured to be still alive and well, languishing in reasonable comfort somewhere in Nanking. Regarding my specific query, my correspondent states that he has been unable to ascertain whether or not Wang Ku ever had any known connections with Morganbrook and Byatt. In his own opinion, however, there is ‘no reason to suppose he would not at some point have had dealings with the aforesaid company’. In those days, my correspondent points out, any shipments of opium – or of any other desirable goods – travelling along the Yangtze through Hunan would have been vulnerable to raids from the bandits and pirates who terrorised the region. Only the warlords through whose territories the shipments travelled could offer any sort of effective protection, and a company like Byatt's almost certainly would have gone some way to securing the friendship of such men. At the time of my childhood in Shanghai, Wang Ku, with the power he then commanded, would have been regarded as a particularly desirable ally. My correspondent's letter closes with his apologies for being unable to provide more concrete details.

As I have said, I did not solicit this information from my correspondent until some five or six weeks after discovering the newspaper picture. The reason for my delay was that annoy-ingly, though I was certain I had seen the plump man somewhere in my past, I could not for a long time remember anything about the context in which I had done so. The man was associated for me with some scene of embarrassment or unpleasantness, but beyond that my memory would yield nothing. Then one morning, quite unexpectedly, as I was strolling along Kensington High Street in search of a taxicab, it all suddenly came back to me.

I had not paid much attention to the plump man when he had first arrived at our house. It was after all only two or three weeks after my father's disappearance and any number of strangers had been coming and going: policemen, men from the British consulate, men from Byatt's, ladies who on entering the house and catching sight of my mother would hold out their arms with a cry of anguish. To these latter, I recall, my mother always responded with a self-possessed smile, and walking up to the lady, would pointedly avoid the embrace, saying instead in her most assured tones something like: ‘Agnes, how delightful.’ She would then take her guest's hands – perhaps still proffered awkwardly in the air – and lead the way into the drawing room.

In any case, as I say, the arrival of the plump Chinese man that day did not much excite my interest. I remember glancing down from my playroom window and seeing him getting out of his motor car. His appearance on that occasion was, I believe, much as it is in my newspaper picture: dark gown, cap, pigtail. I noticed the car was a vast gleaming affair, and that he had two men to assist him as well as his chauffeur, but even this was not so remarkable; in those days following my father's disappearance, a number of very grand visitors had already turned up at the house. I was, though, vaguely struck by the way Uncle Philip, who had been in the house for the past hour or so, marched out to greet the plump man. They exchanged the most effusive greetings – as though they were the dearest friends – then Uncle Philip led the visitor into our house.

I do not remember what I got up to for the next little while. I did remain in the house – though not on account of the plump man, who, as I say, had not much interested me. In fact when I first heard the commotion downstairs, I remember being surprised the visitor was still with us. Rushing back to my playroom window I saw the motor car still on the carriage track, and the three servants who had stayed in the car – who too had heard the disturbance – hastening out of the vehicle with looks of alarm. Then I saw below me the plump man walking quite calmly towards the car, signalling to his men not to worry. The chauffeur held open the door for the plump man and as he was climbing in, my mother came into view. In fact, it had been her voice that had first sent me rushing to the window. I had been trying to convince myself it was just the same voice she used when angry with me or our servants, but by the time my mother's figure appeared below me, her every word now clearly audible, the effort became pointless. There was something about her that had lost control, something I had never seen before, and yet which I at once registered as something I would have to accept in the wake of my father's disappearance.

She was yelling at the plump man, having actually to be restrained by Uncle Philip. My mother was telling the plump man he was a traitor to his own race, that he was an agent of the devil, that she did not want help of his sort, that if he ever returned to our house, she would ‘spit on him like the dirty animal he was’.

The plump man took all this very calmly. He signalled to his men to get in the car, and then, as his chauffeur wound the crank, he smiled from his window almost approvingly towards my mother, as though she were uttering the most gracious of farewells. Then the car was gone and Uncle Philip was persuading my mother to come inside.

By the time they came into the hall, my mother had gone silent. I could hear Uncle Philip saying: ‘But we have to pursue every possible avenue, don't you see?’ His footsteps followed my mother's into the drawing room, the door closed and I heard no more.

Of course, to see my mother behaving in such a way was most disturbing to me. But if she had found shouting at her visitor a liberation after weeks of keeping her feelings on a tight rein, then I too experienced something similar. It was witnessing her outburst that allowed me, after at least two or three weeks, finally to acknowledge the momentous nature of what had happened to us, and this brought with it a tremendous sense of relief.

I will have to admit, incidentally, that I cannot say with complete certainty that the plump Chinese man I saw that day was one and the same as the man in the newspaper photograph – the man now identified as the warlord Wang Ku. All I can say is that from the moment I first set eyes on the photograph, that face – and it was the face, not the gown, cap and pigtail, which of course could have been those of any Chinese gentleman – struck me unmistakably as one I had seen during the days immediately after my father's disappearance. And the more I have turned that particular incident over in my mind, the more convinced I have become that the man in the photograph was the one who visited our house that day. This discovery I believe to be most significant – one that may well help shed light on my parents’ present whereabouts, and prove central to those investigations upon which, as I have said, I intend before long to embark.