So, I gather from the overall ratings that most other people liked this book. I didn't. It usually takes me one night to read a book. I had to spread the reading of this one out over five nights because it was too torturous to do in one sitting. I certainly haven't read the four preceding books in the series, and after this one - I won't be. 
 It was character soup with too much talk about other characters I'd never even heard of. There were tracts of dialogue that left me wondering who the heck was actually speaking - and after rereading those sections three or four times, I gave up and moved on - still in the dark. For me, there wasn't sufficient focus on the development of the emotional connection between the hero and heroine; and there was no explanation at all as to how Acheron actually saved the day at the end. Had the story been better, I might have been curious about Acheron - curious enough to try another book in the series, but I was too dissatisfied to feel curious. 
 My biggest regret is that I bought this book. I'm one of those people who like to help fiction authors by buying their book rather than borrowing it from a library. I use libraries as research centres - a place where I can go and use their reference materials for research. My local library has several books by this author, one of them titled Acheron. They're always sitting on the shelf - every time I go to the library. Obviously not moving. I can understand why. And I won't be touching them. Out of curiosity, I browsed their fiction shelves this morning to see if they had books by other authors I like - they do, but not on their shelves. When I enquired at the lending services counter, I was told that I would need to reserve those titles because they always turn around and head right out the doors again as soon as they are returned by a borrower. It made me feel much better - knowing that I wasn't alone in my reaction to this author's work.