Seth Mason is a Rouge werewolf. Rogue werewolves can't control their shifting during a full moon, when their powers at their fullest. In the Crestfallen Society, Rogue werewolves are supposed to be killed on sight, unless they can prove they are able to control their shifting. When Seth was younger he was an outcast to his pack for not being to be able to control his shifting. It was even more worse since his father was the pack leader, the pack leader of the most powerful werewolf clan. Well, they were the most powerful clan, until Seth killed them all, including his mother, the only person in the pack who didn't hate him.
Now, Seth being Nineteen, he's the pack leader of the most powerful and dangerous pack in the Crestfallen Society, doing secret assasination jobs for one of the head counil members of the Crestfallen Society. But what happens when Seth encounters a target that the head counil member wants dead and Seth imprintes on her? Well, surely it can't be that bad, only if she wasnt a human-vampire hybrid.