There are a lot of 'dark fantasy' books around these days that have given the genre a 'bad' name insofar as their content is what I would call 'supernatural erotica'. If (like me), you prefer your dark fantasy rather more gory and, y'know, DARK, then this could be a book for you.
It's not a huge book, a bit under 200 pages, so if you're looking for epic you'll be disappointed. On the other hand, everything in there is there for a reason, whether it's character development or setup for later events - there's no feeling of redundancy. I'm not a fan of the summary on the back cover: I find it misleading as to the tone and content of the actual book and probably wouldn't have read the book if that was all I'd had to go by.
The story, told from Alice Murphy's perspective, is essentially a recounting of the previous three weeks of her life. It weaves between the 'here and now' police interviewers and the past (despite the title, it's only the chapter headings that are particularly diary-like, no 'dear diary' entries here!), maintaining suspense over exactly what happened, and even managing a very sweet twist in the epilogue.
In conclusion: I would recommend this to any fan of 'gritty' or somewhat 'twisted' fantasy looking for a short, standalone read. It's definitely NOT for younger readers, fans of 'supernatural erotica' (by any other name), or those looking for a Tolkeinesque epic.