Back in the 1990s when Virgin Books launched the Doctor Who New Adventures they advised aspiring writers, like me, that writing a book is hard work and warned that anyone who found it easy was almost certainly doing something wrong. This is perhaps the best piece of advice I have received in my writing career, and it applies to my real work and other aspects of life too.

Currently I am painstakingly checking historical records for 638 different women to see if any of them can be identified as the victim of Jack the Ripper, who called herself Mary Kelly. It relies on the assumption that part of the story about her origins is true, either relating to her personally or borrowed from the history of another person. So far, I have followed numerous promising lines of inquiry, only to discover evidence that ruled out the individual in question. In some ways that’s a success but it increases the possibility that no definitive answers will be found.

At this stage, the book is at least a year away from completion unless I opted to skip the hard work and argued for the most likely identification. That would be wrong.

Paul Williams is a writer of fiction and non-fiction best known for his Jack the Ripper Suspects: The Definitive Guide and Encyclopedia.