Although this book was not my favourite in this series, there is still a lot to recommend it. The forensic detail is wonderful, and written in a fashion that makes it easy to understand. My main complaint with this book is Kay's niece, Lucy. She is not a believable character, and I find her even more unbelievable in this book. My main reason for this is that I don't think an agency like the FBI would have an untrained, young agent like Lucy involved at the heart of their big cases. Yes, I realize she's supposed to be a genius, but seriously, please!! But other than Lucy, I like the other characters, and they are developing very nicely. My favourite is of course, Marino. In this book Kay and Marino are trying to determine the cause of death of a diver that is found dead in the water in an old ship graveyard. Everyone is trying to convince them that it was an accident or suicide, but Kay knows differently, and both her and Marino know that there is very real evil surrounding this death. As they dig deeper, the true extent of the evil is revealed to all, many lives are at stake. This book, like all the others in the series is chock-full of suspense from the opening paragraph right to the very end.