‘Yes, I see French writing, it comes from someone French . . .’ Not difficult, I had just told her that. ‘I see a sailing boat, a kind of half sailing, half motor boat, not very big . . .’ Not a cross-Channel ferry then. ‘I see this woman, I see this death, I see violence on the boat, the cries of violence . . . It’s strange, I see someone diving, trying to get something, but they can’t reach it. As though they are trying to recover something from underwater.

‘Give me another card.’ She glared at the picture I had handed her. ‘It’s not easy . . . give me another card . . . It’s not someone old who did this. Someone of about forty, more or less . . . fortyish, maybe fifty. Another card. Another . . . Does she speak of violence with a man? Something difficult with a man?’

‘The death of her son,’ I answered, and then was annoyed with myself. I had given her an unnecessary clue, the precise relationship of the dead boy. We were fencing.

She nodded, as though it were no surprise. ‘May I touch the letter now?’ she asked.

As she opened the bottle and tipped out the letter she continued to ask questions. ‘How long ago did you find it?’

‘March . . .’ I began and hesitated as I wrestled to convert the year into French.

‘One, two years ago?’ she asked.

Meanwhile she was opening up the bottle, unfolding the letter. The lock of hair fell out. ‘Is this the child’s hair?’ she asked. ‘At all events, the mother has hair like this. Exactly like this.’

I told her there were two separate locks intertwined.

‘Anyhow this is the mother’s hair,’ she repeated. ‘That’s exactly the right colour.’

Another occasion missed when I could have proven her findings – I should have asked her to specify the hair colour before she saw the hair.

She spread the letter out on her desk. ‘The writing is from someone very disturbed,’ she repeated. She shook her head. ‘Before reading it, I would say it’s the writing of someone really disturbed. One would say someone who wants to die.’

She glanced at the first sheet. ‘It’s very long,’ she commented, discouraged by the density of the writing and the number of pages. ‘Why don’t you summarize it for me.’

‘Well,’ I began. ‘Her son died, at the dawn of summer . . .’

‘I have such a terrible headache when I hold this letter,’ the clairvoyant interrupted me. ‘There is a madness in this woman. Does the letter seem coherent to you?’

‘Given that she has lost her son . . .’ I prevaricated.

‘Yes, I see what you mean. Go on,’ she encouraged me.