A young woman's life-saving heart transplant leaves her feeling like an outsider in her own life until she meets a new guy with whom she experiences an undeniable magnetism. Stella is grateful to have survived surgery, but afterward she struggles with her family's and friends' tendency to treat her with kid gloves. Worse, she's plagued by a searing, inexplicable pain that strikes her at exactly the same time each day, making her doubt her sanity. So when gorgeous Levi arrives at her insular private Seattle high school and vigorously pursues her, she's more than ready for the distraction. Being around him seems to produce an actual physical relief that mixes into their steamy attraction. Stella's descent into a haze so unlike her normal behavior that it worries her friends is believable, as are the story's developing chills. Characters are well-developed, including friends Henry (who seems to want more than just friendship) and tough, bawdy Brynn, who has a spot-on sarcastic edge that will be recognizable to many teens: "Okay, lovebird. Stop making me want to vom and don't forget to use protection." In the end, the plotting is largely predictable, but it packs in some authentic scares. Plentiful blood-slicked scenes will please horror fans, but the eerie tone surrounding the central mystery is what works best in this supernatural thriller. (Thriller. 14-18) Kirkus"