“Shiver” has all the ingredients for success in the teen market: forbidden first love, werewolves, and sequels. The book centers around 17-year-old Grace, a girl fascinated with the wolves that haunt the woods behind her house, and Sam, the wolf who saved her years ago. When he appears on her doorstep in human form – only for the summer – the two fall in “Romeo and Juliet”-type serious love. Maggie Stiefvater poetically tells their story in seamlessly alternating points of view, realistically weaving the wolf world into the human. Fans of “Twilight” no doubt flocked to this new take on supernatural romance.