Yet another so-so read in the series. I am a great fan of stories involving codes and cyphers, which I thought this story would be. Instead it was a protracted whodunit investigation with a lot of smoke and mirrors, which would have otherwise been fine, if it had finished with a 'bang' -- which somewhat disappointingly, this book, did not. The ending was somewhat anti-climatic for me. While I still have the last book in this series to read, it would only be fair to say that, (so far) it is this series that does not agree with me because I loved the 'Camel Club' series by the same author.