This book takes place just after the events of River Marked (Mercy Thompson #6) and a few years after Hunting Ground (Alpha and Omega #2). In the time that has passed since the last book in the series, Charles has become more and more affected by the job he does for his father - enforcer and assassin. He is withdrawn and even becoming neglectful of his mate and wife, Anna. 
 After discussion the problem with Anna and Asil, Bran decides to send Anna off to collaborate with the FBI on a serial killer case in Boston - with Charles along as her body guard. They discover that the serial killer who has recently been targeting Werewolves has been operating for decades - and his targets are not that of the human variety. Fae have been disappearing for dozens of years with none of the supernatural world investigating. Now, with Anna and Charles on the case - with the assistance of a few local werewolves and FBI agents - the killer will be stopped. One way or another... 
 For me, this is a very hard book for me to review simply because I loved it. I don't want to come across as a babbling fan girl but I'm afraid I might. 
 I've said it before and I'll probably say it again - I love how Ms. Briggs tortures her characters. Just because she's let Anna and Charles get mated and married does not mean she'll let them have an easy time of it. They're both hurting. Charles especially - not wanting to let the spirits that haunt him to taint Anna but because of this and his pulling away from her, he's hurting her more than ever. 
 I love Anna. And I love Charles. But I think what I love most about them is how they love each other. It's evident in everything they do and how they interact. I think it's really beautiful and a testiment to Ms. Briggs' writing that she can write a fairly gritty urban fantasy novel where romance is very much in the background, and yet their love for each other is so prevalent. 
 The supporting cast in this book were brilliant. I loved the different government agencies and the feelings of forced co-operation between them. I have no doubt that the government would create a new paranormal agency just to handle new issues that would come to light with the werewolves and fae coming out into the world. I also really liked Isaac - the Alpha of the Boston pack. He gave a new insight to a different kind of alpha - you don't need to be an old wolf to be a good alpha. Alistair Beauclaire also interested me. I feel like if Ms. Briggs ever wanted to write another spin-off with the Fae in the forefront, he would be a great character to have in it. Either as a main or serving a similar role to the one that Bran holds in this series. The fae are so interesting! All their magical powers and unspoken rules. I really would love to get a closer look at them. And the witches? I'm rather glad I've never had an encounter with one of Briggs' witches.... they be crazy! 
 Pace wise, there was a lot of groundwork laid at the start of this novel. It did feel a little slow to begin with but after things got moving, I never felt like it was rushed. Everything felt like it was at a natural speed. 
 I loved the action. And I liked that the action scenes showed how Charles has grown as a person since the beginning of the series. He will always be there for Anna - but he now realizes that more importantly for her, she needs to be there for herself. They're so perfect for each other... *dreamy sigh* 
 The wait for the next book is going to be painful for me! I might go into withdrawal! At least I have the other books in the series as well as the Mercy Thompson books to go back and re-read whenever I need my fix.