While the Wolves of Mercy Falls storyline involving main characters Sam and Grace resolved in Forever, Sinner is a spin-off story that follows bad-boy rock star Cole St. Claire and the damaged and distrustful Isabel Culpepper. These characters are a bit older now, living in LA, and as such, Sinner notches up the intensity somewhat, making this book a good choice for a slightly older teen audience. Cole is a passionate, living-on-the-edge musician whose history has become the stuff of urban legend after his disappearance from the music scene into his life as a wolf. He has come to LA ostensibly to film a reality TV show about the making of his next album, but getting Isabel back is his real goal. Isabel is hardened emotionally and finds it nearly impossible to trust Cole and his motives, particularly when he is surrounded by the phoniness of stardom and the contrived situations of the reality show. Their story is one of fiery starts and skidding stops, but one that ultimately sees Cole able to reclaim his soul and Isabel evolving into a feeling person again. The writing in this book is excellent and much time is spent on the emotional experiences of the characters. As one might expect, the trappings of the rock star life surround Cole, but his own particular drug is his lingering ability to turn into a wolf, which he uses as an escape similar to actual drugs. Partying and some sexual activity take place as part of the backdrop of the story, but the interactions between Cole and Isabel are described in more emotional terms than physical. Language is present (b-stard, a-s, sh-t), but not gratuitous. Sinner is a bit grittier and more intense than its predecessors, much like Cole and Isabel were always a bit more complicated and visceral than Sam and Grace. Fans of the series will enjoy.