As a die hard Christie fan, and loving the previous four T&T books, I felt I had to slog through and finish this one, and although the whodunnit is answered after a fashion, I still don't know whydunnit. Christie wrote this one as an aged writer and it shows, with the main characters, themselves in their seventies, prattling on about nothing interesting or germane, and "witness" characters sounding like a visit with aged relatives who talk about people you have never met and they can't seem to quite remember. Although in the end we do find out who did the actual dastardly deed(s), it doesn't seem to matter; I won't type out a spoiler here as far as motive, suffice it to say it was very unsatisfying and confusing. Perhaps an English reader would get more out of it as there are references to what I think are actual historical events that happened in England, but I can only guess. If you are a fan of T&T by all means read this one as it is the last, but for all other Christie readers I say skip it.