There were no answers to these questions. If I discovered her identity and whereabouts, I could plan how – or even whether – to approach her. If she came forward in response to some appeal or advertisement, then she would have made her own decision about whether to be found. Either way, it was easy to postpone thinking about any actual meeting with her. It seemed so far away and so unlikely.

The real facts in the letter were sparse.

1. The son was called Maurice.

2. He was thirteen years old when he died.

3. He was her first son.

4. He died one evening, ‘at the dawn of summer’.

5. The letter-writer, the mother, had a close friend called Christine.

6. There was some material evidence, such as the bottle itself, the paper, the ribbon, the ink, the wood shavings, the lock of hair.

There were some other clues. Were they concrete signs, or simply metaphors?

1. ‘He slipped away from life in an excess of desires’.

2. ‘For a long time he travelled between two waters, between two lights.’

3. She begged forgiveness for not having spoken to him ‘for such a long time’. Either he died a while ago, or they had not spoken for some time before his death.

4. ‘That terrible moment when you slid through my fingers.’

5. ‘My son has reached harbour again, on a faraway shore, close to the rising sun.’

At first I took these clues literally.

The letter-writer was clearly fairly well educated. She had read some Buddhist works, and imbibed some New Age vocabulary. She spoke of God but there were no biblical references, no references to Jesus. Sometimes she referred to ‘Dieu’ with a capital letter, sometimes in lower case. Was this a significant variation or just sloppiness? Did it imply a Protestant who addresses God directly, or a Catholic who remains at a respectful distance? Either way, she was annoyed with him – he had made a serious error by taking her son away, he owed her a recompense. There was no mention of a man, a partner or a father. There was no mention of any other children, though the fact that Maurice was her ‘first son’ implied that he had siblings. There was no mention of Maurice’s childhood, other than the comment that her life had begun with his birth. This expression in itself implied a level of intensity in the relationship between mother and son that neither I nor my friend could completely identify with: I felt I had had an enjoyable and worthwhile life before having children; this woman did not. Or perhaps the death of her son had so altered her perception of her previous life that, in hindsight, only his existence had validated hers. Life after the death of a child can never be the same, but does it cancel out all that went before?

Maurice’s birth had somehow transformed his mother from a non-person into something real. She seemed to be utterly fused with him – I remembered that feeling from the earliest days of motherhood, when independent existence had only just begun for my child and I was still coming to terms with his emergence. But then one tries to build independence for one’s children, and encourage them gently to stand and walk on through life. I remember being shocked by a friend who was still breastfeeding when her child was five, and thinking it reflected her need of him, not any nutritional requirement on his part. Surely by the age of thirteen, such a fusion is no longer a healthy bond.