I reviewed whether I could be bothered to continue searching. Had I been wasting my time not just looking for the wrong kind of death, but looking for the mother at all? Was it not time to give the bottle back to my friend the dog-walker or, with her permission, throw it back into the sea, or simply lock up the cupboard where it sat and get on with the rest of my own life? I was irritated with the ambiguity of the clues, but I still felt that I had many avenues to explore. If, at the end of doing so, my research had advanced no further, I would at least feel that I had tried.

I felt obliged to revisit the statistical information, and as quickly as possible. The lady at INED, the French government Institute of Demographic Studies, was at lunch when I rang back (and anyway I felt a little embarrassed at changing the cause of death after she had been so helpful). On reflection I felt that the Institute’s data would be of limited use. The telephone number I had used for INSERM, the National Institute for Health and Medical Research, no longer responded. So, since I had to start from scratch, I tried to pretend to myself that this was a fresh lead. I would not explain to the bureaucrat why I was searching; I would just pretend to be a journalist researching childhood mortality – the death rates of boys aged, say, thirteen – in a very general way. Somehow this time I got straight through to the director.

He explained that at INSERM they looked at the death certificates and classified the causes of death but then destroyed the documentation. This seemed very unlikely, and I pressed him on it, but he held to his story. My own story crumbled and I soon admitted that I was actually investigating one particular death, of one particular boy, whose name or date of death I did not know. After pointing out the utter hopelessness of my quest, the director told me that it was in fact INSEE, the National Institute for Statistics and Economic Studies, that held death records. However, I would need permission from CNIL, the National Commission for Computers and Freedom, to access anything. He wished me well.

While I was looking up the number for INSEE I was delighted to read on BT’s website that, ‘In France, the language is revered. Therefore when speaking it, do so with care. If your understanding of the language is poor, better to be safe and enquire after an English speaker.’ Sound evidence in theory perhaps, but the next few numbers I rang resulted in a series of rapid answerphone messages, en français naturellement, referring me elsewhere, including freephone numbers that worked only from within France.

By the time I had discovered that this particular service of INSEE only supplied non-specific data for the European Union in its entirety, I felt I had spoken to enough French statisticians and bureaucrats to convince me that I had drained this particular well of information dry, shallow as it was.