When Cain murdered his brother, Abel, he became the world's first murderer. And sins like these don't go unpunished. Actually, in this story, the punishment continues throughout time on the shoulders of Cain's descendants. And Jax is the unlucky successor...the one chosen to bear the burden. 
 Jax has a demon inside him, one that's part of who he is...one that makes him do unspeakable things. But Jax also has an uncle, a brother and a girl he loves. And this really is the crux of this story. This juxtaposition between the evil that lives inside Jax and the love in his heart for these people is too much for him to bear. He can't allow the evil to take over, to hurt anyone he loves. So he turns hard, he moves away, and he gives up what he wants for the safety of those who mean everything to him. But, soon enough he discovers that, even leaving them behind, isn't enough to keep them safe. 
 It's a very intriguing plot filled with good and evil, interesting characters and lots of emotions. The author gives us enough information to ensure we fully understand what Jax is up against but also adds some twists and turns, and some mystery, that is beyond the character's control to keep the story moving. To me, the pace was good in the beginning, allowing us to fully understand both Jax and his demon. It seemed to slow a bit in the middle of the story, maybe more so than was necessary, but definitely picked up at the end. 
 I enjoyed the characters in this book very much. The fact that they've all known each other for many years makes their interactions more believable and their heartbreak that much more intense. Both Jax and Sam are strong characters who, of course, provide us with some tension and angst in the storyline. And the secondary characters, like Jax's twin brother, add depth to the plot. 
 Overall, I think this is a good start to a very interesting series of books. I think that there's a lot to work with here and am interested to see where the author takes things next.