By now the graphologist was well and truly in her stride. ‘She seems nice at first, very gentle, but I think she could be authoritarian if you lived with her. She is not easy to influence. She is basically sensitive, but also – it seems to me – quite touchy, on her dignity. The writing perhaps shows a failure to listen enough. There is an anal dimension to her, in the Freudian sense, and also quite a masculine side to her. It seems to me that the style of writing is rather masculine. There are not many signs of femininity here.

‘She is brave, dignified, faithful. Not great fun, but you can rely on her. Her writing reveals a certain presence, but she is sometimes awkward, not at ease with her space, there is not a great deal of comfort in the writing.’

The graphologist kept returning to the one overriding impression, the sense of a thick, almost suffocating layer of control, plastered over an emotional cauldron. But unless I found the letter-writer, how would I know whether this was a convincing description of a precise, well-organized, obsessive, repressed, sensitive, serious, faithful, courageous woman or just the ramblings of a well-meaning amateur?

We re-twirled the hair into its nest within the letter, scrolled the paper carefully just the way it was and repacked everything into the bottle among the perfumed sandalwood shavings. The graphologist was almost reluctant to let me go. Like many others whose I advice I had asked, she had somehow been touched by the unknown woman’s plight, and she wanted to know the end of the story.

I moved on to the next contact on the orange notelet, the follicologist, the ‘bulbologue’. The three contacts from the artist – graphologist, follicologist and tarot reader – had been offered in a secluded garden in the outskirts of Paris on what had turned out to be a special evening. In French, graphologue, bulbologue, tarologue . . . the list had seemed to offer an alluring magic spell that would solve the mystery without resorting to the vulgarity of an appeal in the media.

However, contact with the follicologist was almost immediately unproductive. I had hoped he would be able to tell me how old the hair was, or the boy’s age when the lock was cut. I had even begun to fantasize that he could find trace elements of drugs in the hair, which might have explained how ‘he slipped away from life in an excess of desires, too full of vivid life’. The assistant mentioned that the analyst could check bone density, stress levels, hormonal imbalances . . . But it was not to be. The hair had, of course, not been torn out by the roots, but carefully snipped in mid-strand. My friend the dog-walker had found it strange that a loving mother should throw away a lock of hair from her son. At any rate, I received a courteous letter from the follicologist:

Dear Madame,