I loved that these characters felt like real people. The details surrounding them was great in the way that you understand who and what the characters look like without going into this long monologue of how they came to be but more important these characters felt like individuals and had their own personalities. Derek is so violent. He's filled with rage at humans and ultimately hates them. He wants to avenge every abused animal out there. Brian is so softhearted it's hard to believe he can handle Derek but he's got a little secret that helps him calm Derek when Derek gets into one of his rages. Honestly, these two were adorable together. They don't change who they are in the end but they come together and you see a new side that's sweet.
One of my favorite things about this story is how Derek is able to get animals to reluctantly comply with what he wants. It's funny because he talks to these animals like they are real people and you get the animals response back. On top of that, Brian can 'speak' to animals so while Derek thinks he's being sneaky by telling a pup that he's never going to have babies if he doesn't come along quietly or how Derek 'comes to an understanding' with Brian's pets, Brian gets told just how dirty Derek is willing to play to do his job and make a relationship work with Brian. It's extremely cute.
My only problem with the book is the conflict. It was over too fast, IMO. I was hoping for something a little more violent or elaborate but, while it was cool to meet a member of the Agency, not much is given on the killing wolf or any of that.
Overall, I loved the story. This is no insta-mates book since Derek and Brian have worked together for two years before anything happened which I found interesting. I liked how they got together and the little funny and cute scenes within it. Looking forward to the rest of the series.