I will say up-front that this was not my favorite Denise Mina book. I prefer her more straightforward mystery stories. This book is written in an interesting manner, though - it's the diary of a husband whose wife is currently in prison for murder. She is a psychiatrist, and she was accused and convicted of killing a serial killer she was treating while he was in prison. She swears she didn't do it, and her husband believes her. His diary reveals all of this thoughts - anger, confusion, changing his mind to think she did it and then back again - as he tries to discover the truth of what happened, searching for something that could set her free.
Mina sets it up as a true crime story - there is a foreword describing how she obtained the diary through perfectly legal means and has finally obtained permission to print it. This is all part of the story, of course, but it sets you up really well to believe it might be true. The best part about the story is how she really gets into the head of the husband writing the diary. It's totally believable, the ups and downs he goes through while trying to find the truth and decide what to do about it. It's very real and very human. And the ending was something I did not see coming. Well, I foresaw a part of it, but certainly not the biggest part of the twist. And I always respect an author who can do that for me, surprise me at the end.
I've read two other of Denise Mina's novels before this, and I think she is fabulous at taking a relatively ordinary paperback mystery kind of story and imbuing it with all kinds of character complexities and real human experience. She's fantastic, and I will keep reading her books!