My enthusiasm for Agatha Christie’s detective stories began when I was 11 in 1967. I was no doubt attracted by Tom Adams’ brilliant paperback covers. In 1969 I joined the Agatha Christie Crime Collection and still have my Certificate of Membership.

Within the next couple of years I had read all of Christie’s detective stories, some more than once, because I was fascinated by the forensic analysis of clues and wanted to assess whether the solutions could really have been deduced from them.

Christie published a handful of further books in the early 1970s and I read them as soon as they were available. But, by the time she died in 1976, I was a student at Magdalene College, Cambridge and my re-reading of her books had become less regular. Instead, I explored some new authors, John Le Carré’s Tinker Tailor Soldier Spy becoming my favourite book.

Subsequently I continued to dip into Christie’s books, taking around 20 years to read them all again, while I qualified then practised as a solicitor in the City of London, becoming a partner in the litigation department of Freshfields (now Freshfields Bruckhaus Deringer) in 1988.

Away from work, my principal hobby at that time – when not watching cricket at Lord’s – was collecting, researching and writing about naval medals, particularly those awarded during the era of Lord Nelson. I wrote articles for the magazine Medal News, for the Orders and Medals Research Society’s Journal and for The 1805 Club’s Trafalgar Chronicle. In that way, I suppose, my writing career had begun.

Then, in the late 1990s, having completed my irregular re-reading of all Agatha Christie’s stories, I came across a book that was about her rather than by her, Professor Robert Barnard’s A Talent to Deceive. In looking at her work thematically, it gave me a new perspective. It also commented very briefly on each of her books, saying in relation to The Man in the Brown Suit that “…the plot would probably not bear close examination, if anyone were to take the trouble”. I remember treating that as a challenge a few years later, having by then read more books about Christie, and I decided to ‘take the trouble’ by writing an analysis of that plot.

As I did so, it occurred to me that plot analysis could be applied to her other novels and that this would be an interesting subject for a book which would appeal to Christie fans. However, I realised that a carefully structured and consistent approach would be required and that I needed to establish, as I subsequently did, that no comprehensive plot analysis of her novels had already been written by another commentator.

It was now 2005 and I embarked on the task of reading whatever books I could find which commented on her novels or on the writing of detective fiction more generally. And, of course, when I then came to analyse and write about the novels themselves over the next ten years, it was necessary for me to re-read them many more times.

As I analysed the novels, I found that I was greatly helped by my career as a litigation lawyer: in that role, I had been constantly using forensic skills, that is, analysing complex series of facts and voluminous documents in a disciplined, inquisitive and detailed manner; extracting the key information from them whilst identifying and trying to resolve gaps, problems and inconsistencies; and then presenting the results in a clear, coherent and organised way.

I retired from Freshfields at the end of 2010 and was then able to dedicate more time to writing about the novels, at home in Wimbledon, where I live with my wife Linda who is a Master of Wine. We have two adult children. And a very chatty cat.