Three things made me read this book.
1. The author has a massive following on Twitter and blogs about Indie writing, handing out advice and tips.
2. The reviews are mostly gushing and fullsome in their praise.
3. It was available as a free download.
I have to admit to being ever so slightly disappointed. It's essentially a good story, well structured, with a few clever twists and touches, and he does a good job of juggling the possibilities and suspects. Unfortunately, I guessed the ending about half way through so, for me, it was less revelatory than many other reviewers found it. That's not to say it is patently obvious (it's not) or that I am some kind of genius (as if!), I just thought it was good rather than gobsmacking.
I didn't enjoy a lot of the dialogue. It tended to consist of the characters summarising or describing what had just occurred in the preceding chapter or paragraphs, which made me skim or ignore it. I also thought the description of tone, emotion and so on after each sentence uttered was overdone.
I found the number of grammatical errors - a your instead of a you're for instance - and typos a bit off-putting. With modern electronic files, it is easy to go in and fix such things. This book is several years old and there are other reviews pointing out these glitches. Given the author's penchant for giving advice on writing, I think he should go back over the text and fix these. Don't get me wrong, it is not such a problem that it would spoil the read or the story, but it would improve it if he did.
Overall, I would say it is worth reading and given that the vast majority of readers appeared to thoroughly enjoy it, my nit-picking is likely just that! I suspect my expectations were just a little too high going into it.