It is now already over a year ago. I had been sitting near the back of the church – the bride was not expected for several more minutes – when I saw Sarah come in with Sir Cecil Medhurst on the other side of the nave. Certainly, Sir Cecil did not look appreciably older than when I had last seen him on the evening of the Meredith Foundation banquet in his honour; but the many reports that he had been hugely rejuvenated by his marriage to Sarah appeared to be something of an exaggeration. He looked happy enough, none the less, as he gave jovial waves to people he recognised.

I did not speak to Sarah until after the service. I was strolling around the churchyard amidst the chattering guests, and had paused to admire a flower bed, when suddenly she appeared at my side.

‘Now, Christopher,’ she said. ‘You're virtually the only one here not to have congratulated me on my hat. Celia Matheson made it for me.’

‘It's splendid. Really very impressive. And how are you?’

It was the first time we had spoken for some time and I believe we chatted politely for a while as we moved slowly around the fringes of the crowd. Then when we paused again, I asked:

‘And Sir Cecil is well? He's certainly looking very fit.’

‘Oh, he's on splendid form. Christopher, you can tell me. Were people utterly horrified I married him?’

‘Horrified? Oh no, no. Why should they be?’

‘I mean, about his being so much older. Of course, no one will say so to us. But you tell me. People were horrified, weren't they?’

‘As far as I was aware, everyone was delighted. Of course, people were surprised. It was all so sudden. But no, I believe everyone was delighted.’

‘Well then, that only proves what I feared. They must have seen me as an old maid. That's why they weren't horrified. A few years ago, I'm sure they would have been.’

‘Really …’

Sarah laughed at my discomfort and touched my arm. ‘Christopher, you're so sweet. Don't worry. Don't worry about it at all.’ Then she added: ‘You know, you must come and visit. Cecil remembers meeting you, at that banquet. He'd love to see you again.’

‘I'd be delighted.’

‘Oh, but it's probably too late now. We're going away, you see. Sailing for the Far East in eight days’ time.’

‘Really. Will you be gone for long?’

‘Might be months. Perhaps even years. Still, you must come and see us when we get back.’

I suspect I was a little lost for words at this news. But just at that moment, the bride and groom came into view across the grass, and Sarah said:

‘Don't they look so handsome together? And they're so suited.’ For a moment she gazed at them dreamily. Then she said: ‘I was asking them just now what they wished of the future. And Alison said they just want a little cottage in Dorset, from which neither of them need emerge for years and years. Not until there are children, and they're getting grey hairs and wrinkles. Don't you think that's so wonderful? I do so wish it for them. And it's so wonderful, the way they happened to meet just by chance like that.’

She went on gazing at them as though hypnotised. Eventually she came out of her trance, and I believe we spent a few minutes exchanging news of mutual friends. Then others came to join us, and after a while I drifted away.

I was to encounter Sarah once more, later in the day, at the country house hotel overlooking the South Downs where the reception was held. It was towards the end of that afternoon, and the sun was low in the sky. An unusual amount of drink had been consumed by then, and I remember walking through the hotel past groups of dishevelled guests, scattered across sofas and propped uncertainly in alcoves, until coming out on to the windy terrace I spotted Sarah, leaning against the balustrade, looking out over the grounds. I was walking towards her, when I heard a voice behind me, and saw a stout, red-faced man hurrying across the terrace after me. He grasped my arm, then stood there recovering his breath, looking into my face with a serious expression. Then he said:

‘Look, I've been watching. I saw what happened, and I saw them earlier too. It's a disgrace, and as the brother of the groom, I want to extend my apologies to you. Those drunken oafs, I don't know who they are. I'm sorry, old chap, it must have been awfully upsetting.’

‘Oh, please don't worry,’ I said with a laugh. ‘I'm not in the least offended. They've had a little to drink and they were just amusing themselves.’

‘It's barbaric behaviour. You're a guest, just as they are, and if they can't be civil, they'll have to go.’

‘Well really, I think you've got the wrong end of the stick. They didn't mean anything. In any case, I certainly took no offence. A fellow's got to be able to take a little joke sometimes.’

‘But they've been at it all afternoon. I saw them earlier, even at the church. This is my brother's wedding. I won't have behaviour of this sort. In fact, I'm going to sort the whole thing out here and now. Come with me, old fellow. We'll see if they still find you so amusing.’

‘No, look, you don't understand. If anything, I was enjoying the joke just as much as they were.’

‘But I won't have it! Far too much of this kind of thing goes on these days. They get away with it more and more, but not today. Not at my brother's wedding. Come on, you come with me.’

He was tugging at my arm and I saw beads of sweat all over his face. I am not sure what I would have done next, but just then, Sarah came strolling up to us, a cocktail in one hand, and said to the red-faced man:

‘Oh, Roderick, you have got the wrong end of the stick. Those are friends of Christopher's. Besides, Christopher's the last person you need to protect.’

The red-faced man looked from one to the other of us. Finally he asked Sarah: ‘Are you sure? Because I've seen it go on the whole day. Every time this chap goes anywhere near them …’

‘You worry too much, Roderick. Those are friends of Christopher's. If he were in the least bit cross with them, you'd soon know all about it. Christopher's quite capable of dressing them down himself. In fact, Christopher here could have them cowering, or else eating out of his hand, whatever he pleases, in the wink of an eye. So off you go, Roderick. Go off and enjoy yourself.’

The red-faced man regarded me with a new respect, then in his confusion held out his hand. ‘I'm Jamie's brother,’ he said, as I took it. ‘Pleased to meet you. If I can do anything, well, you come and find me. I'm sorry if there was some misunderstanding. Well, enjoy yourself.’

We watched him lurch back towards the house. Then Sarah said:

‘Come on, Christopher. Why don't you come and talk to me for a while.’

She took a sip from her glass and strolled off. I followed her across the terrace until we were at the balustrade, looking out over the grounds.

‘Thank you for that,’ I said eventually.

‘Oh, it's all part of the service. Christopher, what have you been up to all afternoon?’

‘Oh, nothing much. In fact, I was just thinking. About that night a few years ago, that banquet for Sir Cecil. I was wondering if when you met him that night you had any idea you'd one day …’

‘Oh, Christopher’ – she cut across my words and I realised she was fairly drunk – ‘I'll tell you, I can tell you. When I met Cecil that night, I found him very charming. But really, I thought nothing more of him. It was only much later, oh, a year later, even more. Oh yes, I'll tell you, you're such a dear friend. I was at this supper and people were talking about Mussolini, and some of the men were saying it wasn't a joke any more, there could well be another war, even worse than the last one. That's when someone brought up Cecil's name. Said we needed people like him more than ever at a time like this, and he really shouldn't have retired, surely he had plenty of steam left yet. Then someone said, he's the man to undertake the great mission, and someone else said, no, it's not fair on him, he's too old, he's got no close colleagues left, he doesn't even have a wife now. And that's when it came to me. I thought, well, even a great man like that, with all his achievements, he needs someone, someone who'll make the difference. Someone to help him, at the end of his career, to summon up what's needed for one last great push.’

She fell quiet for a moment, so I said: ‘And it would appear Sir Cecil came to see it that way too.’

‘I can be persuasive when I wish to be, Christopher. Besides, he says he fell in love with me right from that time he first saw me, at that banquet.’

‘How splendid.’

Below us, down on the grass, some way in the distance, several guests were larking about by the pond. I could see one man, his collar sticking out behind his neck, charging at some ducks. Eventually, I said:

‘This business of Sir Cecil making a final push. His crowning achievement. What exactly was it you had in mind for him? Is this why you're going away for months?’

Sarah took a deep breath and her gaze became serious and steady. ‘Christopher. You must know the answer.’

‘If I knew the answer …’

‘Oh, for goodness’ sake. We're going to Shanghai, of course.’

It is hard to describe just what I felt when I heard her say this. Perhaps there was still some element of surprise. But more than anything else, I recall a kind of relief; an odd feeling that from the time I had first laid eyes on her all those years ago at the Charingworth Club, a part of me had been waiting for this moment; that in some sense, my whole friendship with Sarah had always been moving towards this one point, and now at last it had arrived. The few words we then went on to exchange had about them a strangely familiar ring, as though we had rehearsed them somewhere many times already.

‘Cecil knows the place well,’ she was saying. ‘He feels he might be able to help sort things out over there and he felt he should go. So go we shall. Next week. Our bags are virtually packed.’

‘Well, then, I wish Sir Cecil, I wish you both, the very best in accomplishing your mission in Shanghai. Are you looking forward to it? I get the impression you are.’

‘Of course I am. Of course I'm looking forward to it. I've waited a long time for something like this. I'm so tired of London and … and all of this’ – she waved back towards the hotel. ‘I wasn't getting any younger, and sometimes I thought my chance would never come. But here we are, we're going to Shanghai. Now, Christopher, what's the matter?’

‘I suppose this might sound rather feeble to you,’ I said. ‘But I'll say it anyway. You see, it's always been my intention to return to Shanghai myself. I mean, to … to solve the problems there. That's always been my intention.’

For a moment, she went on gazing out at the sunset. Then she turned and smiled at me, and I thought her smile was full of sadness, and tinged with rebuke. She reached out a hand and touched me gently on the cheek, then turned back to the view again.

‘Perhaps Cecil will solve things quickly in Shanghai,’ she said. ‘Perhaps he won't. In any case, we might be there a long time. So if what you just said is true, Christopher, then it's quite possible we shall see you out there. Isn't it?’

‘Yes,’ I said. ‘Indeed.’

*

I was not to see Sarah Hemmings again before she set sail. If she had every right to rebuke me for my procrastination over the years, then how much more deserving of her disappointment would I be should I now fail to act? For it is self-evident, whatever progress Sir Cecil has made out in Shanghai during the intervening months, a solution is still nowhere in sight. Tensions continue to mount the world over; knowledgeable people liken our civilisation to a haystack at which lighted matches are being hurled. Meanwhile, here I am, still languishing in London. But with the advent of yesterday's letter, it might be said that the last pieces of the jigsaw have come together. Surely the time has finally arrived for me to go out there myself, to Shanghai, to go there and – after all these years – ‘slay the serpent’, as that decent West Country inspector put it.

But it will be at some cost. Earlier this morning, as yesterday, Jennifer went out shopping – for a few last items she claims are imperative for the new school term. When she left, she appeared excited and happy; she knows nothing yet of my plans, or of the things Miss Givens and I discussed last night.

I asked Miss Givens into the drawing room and had to invite her to sit down three times before she did so. Perhaps she had an inkling of what I wished to say, and felt that to sit with me would amount to some form of collusion. I laid the situation out to her as best I could; tried to make her understand the vast importance of the case; that it was, moreover, one I had been involved with for many, many years. She listened impassively, and then when I paused, asked her simple question: how long would I be gone? I believe then I talked for some time, trying to explain to her why it was impossible to place a clear time frame on a case of this sort. I have a feeling it was she who interrupted me eventually to raise some query, and after that we spent several minutes on the various practical implications of my going away. It was only after we had discussed these matters fairly exhaustively, and she had risen to leave, that I said to her:

‘Miss Givens, I'm fully aware that in the short term, even with your best efforts, my absence will bring difficulties for Jennifer. But I wonder if you've considered that in the longer term, it's almost certainly in our best interests, Jenny's and mine, that I pursue the course I've just outlined to you. After all, how will Jennifer ever be able to love and respect a guardian who she knew had turned away from his most solemn duty when the call finally came? Whatever she may wish for now, she'll come to have only contempt for me when she's older. And what good would that do either of us?’

Miss Givens gazed at me steadily, then said: ‘You have a point, Mr Banks.’ Then she added: ‘But she will miss you, Mr Banks, none the less.’

‘Yes. Yes, I dare say so. But Miss Givens, don't you see?’ I might have raised my voice at this point. ‘Don't you see how very urgent things have got? The growing turmoil all over the world? I have to go!’

‘Of course, Mr Banks.’

‘I'm sorry. I do apologise. I'm somewhat overwrought tonight. All in all, it's been quite a day.’

‘Would you like me to tell her?’ Miss Givens asked.

I thought about this, then shook my head. ‘No, I'll speak to her. I'll speak to her in good time. I'd appreciate it if you said nothing to her until I've seen her.’

I had intended last night to talk to Jennifer some time today. But on further thought, I feel to do so might be premature; it might, moreover, quite unnecessarily sully her current very positive mood concerning her forthcoming school term. It will be better, all in all, to leave the matter for now, and I will be able to go and see her at her school once I have finalised my arrangements. Jennifer is a child of remarkable spirit, and there is no reason to suppose she would be so devastated just on account of my departure.

I cannot help, though, recalling now that winter's day two years ago when I first visited her at St Margaret's. I had been conducting an investigation not far away, and this still being early in her career at the school, I had decided to call to check that all was well.

The school comprises a large manor house surrounded by several acres of grounds. Behind the house, the lawn slopes down to a lake. Perhaps on account of this latter, on each of the four occasions I have visited the school, I have found mist enveloping the place. Geese wander freely, while sullen gardeners tend to the marshy grounds. It is, by and large, a rather austere atmosphere, though the mistresses, in so far as I have seen them, present a warmer face. On that particular day, I remember a certain Miss Nutting, a kindly woman in her fifties, leading me through the chilly corridors. At one point, she paused by an alcove and, lowering her voice, said to me:

‘All things considered, Mr Banks, she's settling in as well as can be expected. After all, there are bound to be a few difficulties for her at the start, while the other girls still see her as a newcomer. And one or two of them can be a little cruel sometimes. But by next term, that will all be behind her, I'm sure.’

Jennifer was waiting for me in a large, oak-panelled room where a log was smouldering in the fireplace. The mistress left us, and Jennifer smiled rather shyly from where she was standing in front of the mantelpiece.

‘They don't keep things very warm here,’ I said, rubbing my hands and moving towards the fire.

‘Oh, you should feel how cold it is in our dorm. Icicles on your sheets!’ She giggled.

I sat down in a chair close to the fire, but she remained standing. I had feared she might feel awkward seeing me in this different context, but she soon began to chat quite freely, about her badminton, the girls she liked, the food, which she said was ‘stew, stew, stew’.

‘It's sometimes difficult,’ I put in at one point, ‘when you're new. They're not … ganging up on you or anything?’

‘Oh no,’ she said. ‘Well, there's a bit of teasing sometimes, but they mean nothing by it. They're all nice girls here.’

We had been talking for twenty minutes or so when I rose to my feet and handed her the cardboard box I had brought in my briefcase.

‘Oh, what's this?’ she exclaimed excitedly.

‘Jenny, it's not … it's not a present as such.’

She caught the warning in my voice, and looked at the box in her hands with a sudden wariness. ‘Then what is it?’ she asked.

‘Open it. See for yourself.’

I watched her remove the lid of the box – roughly the size of a shoe box – and stare inside. Her expression, already cautious, did not change at all. Then she reached in a hand and touched something.

‘I'm afraid,’ I said gently, ‘that's all I could recover. Your trunk, I discovered, wasn't lost at sea at all, but stolen along with four others from a London depot. I did what I could, but I fear the thieves simply destroyed what they couldn't sell easily. I could find no trace of the clothes and such. Just these little things.’

She had brought out a bracelet, and was examining it carefully as though checking for blemishes. She put it back, then took out a pair of tiny silver bells and examined them in the same way. Then she put the lid back on the box and looked at me.

‘It was very kind of you, Uncle Christopher,’ she said quietly. ‘And you must be so busy.’

‘It wasn't any trouble. I'm just sorry I couldn't recover any more.’

‘It was very kind of you.’

‘Well, I'd better let you get back to your geography lesson. I didn't come at a very convenient time.’

She did not move, but continued to stand there quietly, gazing at the box in her hands. Then she said:

‘When you're at school, sometimes, you forget. Just sometimes. You count the days until the holidays like the other girls do, and then you think you'll see Mother and Papa again.’

Even in these circumstances, it still came as a surprise to hear her mention her parents. I waited for her to say more but she did not; she simply gazed up at me as though she had just put to me a question. In the end, I said:

‘It's very difficult sometimes, I know. It's as though your whole world's collapsed around you. But I'll say this for you, Jenny. You're making a marvellous job of putting the pieces together again. You really are. I know it can never be quite the same, but I know you have it in you to go on now and build a happy future for yourself. And I'll always be here to help you, I want you to know that.’

‘Thank you,’ she said. ‘And thank you for these.’

As far as I recall, that is how our meeting ended that day. We moved beyond the relative warmth of the fire, across the draughty room and out into the corridor, where I watched her walk away back to her class.

That winter's afternoon two years ago, I had no idea that my words to her were anything other than well founded. When I next visit St Margaret's, to say goodbye, we may well meet again in that same draughty room, by that same fire. If so, things will be all the harder for me, for there is little chance Jennifer will fail to remember very clearly our last encounter there. But she is an intelligent girl, and whatever her immediate emotions, she may well understand all that I will say to her. She may even grasp, more quickly than did her nanny last night, that when she is older – when this case has become a triumphant memory – she will be truly glad I rose to the challenge of my responsibilities.