The main character, Vincent, is an ex-Intelligence agent who goes MIA, presumed dead, and takes up his own personal mission to expose horrific medical testing being funded by the British government. This lands him in the middle of a very sensitive subject: medical research can lead to life-saving breakthroughs, but is based on horrible exploitation and torture. If your life, or your child's life, could be saved by performing experiments on foreign prostitutes, should the experiments be carried out? What about on beagles or rats? Is it okay to torture and kill unwilling and completely innocent victims in order to (maybe) save other lives?
As you can see, this is a book with an agenda, one that I happen to agree with (namely, vivisection is unconscionable and should be replaced with other methods). If the very idea of stopping or changing medical research out of concern for its test subjects is repellent to you, than you're probably not going to like this book. However, if you're interested in a thriller that isn't afraid to delve into some sticky issues with no easy answers (is it okay for a rogue agent to kill killers in order to stop the killing??), this book has a lot to offer. And don't let the "serious" side of the book deter you if you're looking for a fast-paced thriller: this book has lots of tension and some high-action sequences that quite frankly had me on the edge of my seat."