In this brooding fourth novel, Picoult (Picture Perfect, 1995, etc.) creates an affecting study of obsession, loss, and some of the more wrenching varieties of guilt. It all begins with a failed suicide pact between two teenagers: Emily Gold dies, but the precise motivations behind her death remain obscure. And who pulled the trigger? Her boyfriend Chris Harte, who survives because of having fainted--apparently--before he could kill himself, seems unwilling to offer an explanation. Zipping back and forth through time, the story traces the growth of the long, complex relationship between the kids. When the two families first settle down next to each other, the Hanes and Golds seem meant for each other: Both families are upper-class New Englanders; both the husbands are doctors; both the wives are pregnant--and so in a sense the pairing of Chris and Emily takes place even before their birth. Eventually, they sleep in the same bassinet, go on to develop their own secret language, accompany each other everywhere and, when they become adolescents, are inevitably drawn into a fervid romance. While it seems inconceivable that Chris could have killed Emily, a preponderance of forensic evidence suggests that it just may be. On his 18th birthday, Chris is hauled off to jail and the perfect harmony between the families instantly dissolves. Melanie Gold, unable to accept the notion that her perfect daughter could have been suicidal, focuses her anger on the murderer next door, and, emotionally, James Harte disinherits his son, who's now a liability to the doctor's prestigious career. Chris himself, saddled with a hot-shot lawyer more interested in building a case than in hearing the truth, sinks into despair. The trial scenes, alternating rapid-fire testimony with flashbacks to the actual suicide, are particularly powerful, and what Chris finally says when he takes the stand comes, thanks to Picoult's skill, as a considerable surprise. A moving story, mingling elements of mystery with sensitive exploration of a tragic subject.