But what of the letter that Thomas enclosed with the book? Well, I made myself read it, although I confess I waited several days before I could bring myself to take it from its hiding place, unfold it and spread it on my table.

My dear William,

I can say nothing that will make things right between us because I know now that nothing can ever do that, even though so many years have gone by. We cannot reclaim the past and should not even try, although I wish with all my heart that we could have spoken earlier. I return your book to you at last. You sent it back to me, but now, at the end of my life, I must return it where it belongs as a token of my continuing affection for you. I did a great wrong to you and to the woman you loved. But you must have wondered why I did not admit my fault earlier. You must have thought the worse of me for it. I have suffered with that knowledge all my life, without being able to remedy it in any particular, for fear that you would think I was seeking only to justify my actions. Now, at the end, none of this matters. So I can tell you.

The reason why I did not confess everything to you at the time, was that I had some hopes – vain hopes I now see, for God help me, my thoughts were all on you and our friendship and our future travels, and not on the poor lassie – I had some hopes that all might yet be well between us. That Jenny had found some kindly house where she might give birth, that she would come home bringing the child with her, that you would marry her, without ever discovering my part in the deception, for how could she possibly tell you? I thought at first that you might believe the child to be yours, but when you told me that could not be, I hoped, nay, I was sure that you – the loving, honourable William I knew – might marry her, child and all, without ever discovering the truth of its parentage. It is the kind of secret that many women have carried with them to the grave. My work as a doctor had taught me that, at least. I hoped that you would decamp to Ayrshire, where I might visit you. Where I might join you in due course, since I was well aware that my uncle had only one son, and he, God help him, was in very poor health. I hoped that this house might ultimately come to me, as in fact it did, not from any motive of greed, but because I thought that the two of us might do wonderful things with the gardens here.

I must ask you to believe me, although it may seem incredible to you, when I say that I had no thoughts whatsoever of continuing the affair with Jenny. I do not know why I even began it, although you must also try to believe me when I say that she was a willing partner. There was no coercion involved. And I thought that this solution would be best for all concerned. I believed that I would be able to do my duty by the child, paying for its education, much as a loving uncle might, that I would be able to retain your friendship, which I valued above all else and, if you can believe me, still do. That I would be able to achieve some sort of peace with Jenny, for whom I always had the highest regard. I constructed such dreams, such castles in the air. Can you imagine?

Reading over this now, this letter that I have written, these many years later, I can see that you will be filled with disbelief. Your face comes before me, with all your innate intelligence and scepticism. But I ask you to try to remember the man you knew then, and for whom, I believe, you had some affection, just as he had such fondness for you, such dreams and ambitions for the pair of us.

Why did I do it? If you have asked yourself that a hundred times, believe me when I say that I have asked myself the same question a thousand times and more. Why? How could I do it to you of all people, to a friend whom I never wished to hurt or harm in any way? I could say that it was a momentary lapse, but that would not quite be true. I was very fond of her. I charmed her, thoughtlessly. She was enchanted for a brief spell and so was I. I think you never fully blamed her, and I hope you never will. But that is not the whole of it. Had she been any other lass, no matter how beautiful, how accomplished, I think I would not have fallen. But your lass. Yours. Why did I do that? It was a kind of lunacy. I confess it, William. I would watch you and I would feel that I knew you better than I knew myself. But then I would become all unsure. Could it be true? Did I ever know you at all? I think there was a part of me that wanted her because she was yours, but not out of envy. I think I wanted, needed to know what you knew, felt as you did, to get inside your mind in all possible ways.

Is this credible? Is this not the very essence of what I was, back then? Thoughtless, sometimes. But full of dreams and imaginings. Wholly impulsive, wholly loving, ever hopeful that I could turn the world the way I wanted it to be. My dreams were so very real that I never wished to wake from them. Well, well. My self-love was my downfall in the end. But worse, it caused the death of an innocent young woman and her child. My child. And a most terrible and unforgivable injury to you, my dear companion. You must believe this if nothing else: I have spent a lifetime repenting of my folly. I wish to God you had written to me before this, for I had not the courage and now I think I do not have the strength to see you again, but wanted only to send you these words.

Your fond and loving friend, as ever,

Thomas

Well, I did read it with a certain scepticism. But I also asked myself, was this not the very essence of the Thomas I had once fancied I knew well? We were three points of a triangle. And afterwards, when passion was spent and reality intervened, my poor Jenny would have presented herself and her condition to him as a problem that had to be solved to everyone’s satisfaction. The logical solution, as he saw it, was that I should marry her. Then everyone would be happy, not least Thomas Brown. But he had reckoned without Jenny’s pride, Professor Jeffray, his chain saw and his dissecting rooms.

Thomas must have fallen ill, mortally ill, not long after he wrote that letter, or perhaps he was already feeling the first stirrings of whatever killed him. But he had written it, put it inside the book, parcelled up the whole and directed that it be sent to me upon his death. No sentimental deathbed reconciliation for Thomas. That was not his way. I could see that now.

And so I come to the end of my story. And I hope that you can understand why that terrible book, The Anatomy of the Human Gravid Uterus, brings back such an agony of mind, brings back to me the image of the lovely soul that was Jenny, with the child, Thomas’s child – why did I not realise for so many years what a sudden and unimaginable horror that must have seemed to him? – still inside her, laid bare upon that table for all to see, for Jeffray to approach, wielding his chain saw, demonstrating its efficacy in such cases. It will not do. I cannot think about it, for even now, it makes me sick and angry and like to vomit. So instead I turn my attention to the book that Thomas saw fit to send back to me, the old gardening book that we had once pored over together and that I had returned to him in a rage. I read the lines that are obscurely comforting still.

‘Choose your seeds from the high, straight, young and well thriving. Choose the fairest, the weightiest, and the brightest for it is observed that the seeds of hollow trees, whose pith is consumed, do not fill well or come to perfection.’

Was he but a hollow tree? For he certainly did not come to perfection. But neither did I, so perhaps I was always overly cautious, never quite sturdy enough.

‘The black cherrie is a tree that I love well. There is a sort at Niddrie Castle whose fruit is preferable to any cherrie. I take it to be a soft heart cherrie but it’s a great bearer.’

A soft heart cherry. That was what I was, back then when we used to recite the words as one might recite poetry with a friend. I could remember it as if we had spoken the lines only yesterday, blithely, thinking of our old age as something so remote as to be unimaginable.

‘Gather their fruit when full ripe, eat of the fleshy part and lay the stones to dry a little.’

We were young and strong and full of hope for a happy ending, just as my grand-daughter Jenny is still young and strong, with a head full of dreams and possibilities for her own magical future.

‘Some trees there be that will not bear of themselves till they be old, but if you cut off the head of the shoots and then take out some great boughs, if you mind your time and do it with discretion, you may force your tree to put forth buds and bear.’

Our minds were so very much in tune. We were like two halves of the same fine fruit, Thomas and I. We had thought to plant trees, like weans, and watch them grow. We had thought, perhaps, to force each other to put forth buds and bear knowledge. And so we did. But as well as the knowledge of good, we found the knowledge of evil. And in the end, trees are no substitute for people.

* * *

There is a last great truth that comes to me now, as I sit here in the autumn of the year. It is a truth that has lurked at the back of my mind for a long time; one that I never wished to bring out and examine in the light of day. Untenable you see. I never thought to do it until now. At this time of life you feel, oddly, that everything matters but nothing matters very much.

I loved Jenny Caddas, that’s one truth. And I missed her. I miss her yet. But all the same, if you were to ask me what it was that made and sometimes still makes me wake in the night with a sense of regret that feels like an amputation, a lost limb that aches fiercely, bitterly, then I cannot in all conscience say that it is the thought of Jenny. My feelings for her have mellowed through time. My grand-daughter, who looks more like her great-aunt than her grandmother, comforts me, brings her before my eyes, heals the thought of her.

I loved my wife. That’s another truth. We were absolutely faithful, throughout the long years of our marriage, and perhaps what’s more important, we were always kindly to one another, each making allowances for the other. I have nothing to reproach myself with, now that she has gone.

So it is not Jenny or Anna that I think of at those times. It is something quite different. And I tell you, without guilt or even very much surprise, that it is Thomas I think of. It is our friendship, the affection that lay between us once, perhaps most of all those days of intimacy and ease on the Isle of Arran or in the college gardens, among the trees. I think of the attachment, the fondness that was all lost, all wasted, like some exotic flower, trampled underfoot. It is the thing that he betrayed, as I could not. What pains me most is the absolute certainty, even now, that I would not have so betrayed him, no matter what the reason. I would have died first.

I think afterwards that he blamed me for my lack of forgiveness, for my persistent distrust of him. But he did not understand the full extent of the wound that lay deep within my heart. Or perhaps, as he tried to tell me in that last letter, he hardly thought of it as a betrayal at all, but as something that he was driven to do by his need to put himself in my place. Can I bring myself to believe that? I would certainly like to do it. The wound healed over, in time, but the ache of it is with me yet. Whatever motives and excuses he may have had, nothing can change that. He was a good man, even a great one, but I still think that my affection for him was stronger than his for me.

Or do I? Was it not simply different? What comes to me is the thought of what was lost, of all that we might have done, the places we might have gone, the work we might have achieved together. None of which is in any way to devalue what I have, which is very precious to me. You must understand that. We are like that, we human beings. We can regret what might have been, even while loving and cherishing and holding fast to what we have.

So I confess, it is the thought of Thomas that sometimes makes me wake in the night with a sense of regret so profound, so bitter, that it is like a physical pain in me and I shift and squirm with it and must light a candle and bury my nose in a book so as to be rid of it. What’s for you won’t go by you, my mother would have said. Looking up at the night sky, you will maybe see a shooting star and sometimes it seems to fall to earth and sometimes it seems to hurtle past and travel on its way to another time and place. But I am not sure which is which, whether that star is myself, or whether it was Thomas, who hurtled past me, dazzled me, blinded me to all else and then travelled on his way.

And still he comes before my eyes. My dearly beloved friend. Not the crabbit old man he no doubt became. How would I know? I never saw him again. But tall Thomas, with his grey eyes, his strong limbs and his warm smile, as he walked into the garden in search of me, Thomas, talking to me of thistle and valerian and sweet honeysuckle. Thomas, admiring the wayfarer tree and laughing uproariously at the thought of the students trying to set fire to it, and the vision of me chasing them with a spade and swearing at them. Thomas, full of ideas and ideals. Thomas, who loved to teach, and talk, who loved, more than anything, the imparting of knowledge, which is not always the same thing as wisdom.

My Jenny has just come into the room.

She looks at me and says, ‘You’re sad!’

I tell her that I have dust in my eyes. Dusty old books just.

She loves books too, and often asks me to read to her, but I tell her that she must not devote all her life to them. No. I tell her that she must be out and about in the world, breathing the fresh air. She can enjoy her books if she wishes, but she must not elect to live life at second hand. Books are but a poor substitute for experience, no matter how painful. I do not think she understands me yet, but she will, in time, God love her.

Now she takes up my linen handkerchief and wipes my eyes with it, much as I sometimes wipe her own when she weeps over her small troubles.

‘There now,’ she says. ‘Is that better?’

And I tell her that it is. That all is well. That we will put the dusty old books away for the time being, and perhaps I will come down into the garden for a walk, before supper, for I may be in the winter of my years, but it is still a fine, golden autumn and besides, the very essence of spring is here beside me, tugging at my hand and, however much the city has grown, tonight the air out there among the trees seems very sweet.