As she did with her first novel, Shattering Glass, Giles once again proves that she knows intimately the workings of the adolescent mind, even if the ending here may raise more questions than it answers. "Things had been getting a little better until I got a letter from my dead sister," begins 14-year-old narrator Sunny Reynolds. Her 18-year-old sister, Jazz, allegedly perished in a fire in February in New York City, although her remains could not be identified. So when a letter arrives from Jazz in May, saying that she will arrive on Sunday, Sunny has mixed feelings. Since Jazz's death, Sunny's mother has been severely depressed and her father has stepped up his drinking. "Everybody misses Jazz. Everybody but me," says Sunny. But the girl who arrives on Sunday is not Jazz. Unraveling the mystery of this girl's true identity keeps the pages turning, but the strength of the novel lies in the convincing interactions between Sunny, her parents and the imposter. Scenes of Sunny and her father tiptoeing around Sunny's emotionally fragile mother raise the stakes, and Sunny's decision to confront the intruder herself is the highlight. Unfortunately, the swift wrap-up (in which Sunny's maternal grandmother arrives and delivers a confusing denouement) undercuts the carefully crafted nuances of complicated familial relationships.