THE STORY OF Cassie Bernall’s final moment is known worldwide. She was a typical 17-year-old at Columbine High School in Littleton, Colorado, studying in the library, when two berserk classmates held a gun to her head and asked if she believed in God. She said, yes; the gun was fired, conferring, in some minds, instant martyrdom. Twelve others also died. Whether or not Cassie Bernall said “yes” to her murderer just before he shot her ? and recent news reports have raised questions about this ? is less relevant than the story of her life in the three years previous. This is a mother’s story of a “prodigal daughter,” defiant, angry, influenced by Satanist friends, fantasizing about killing her parents, who “came to herself” through a combination of parental tough love and the ministry of a Christian peer. Drawing on her own searing memories, interviews with classmates, and Cassie’s notes and letters, Ms. Bernall recounts the dramatic transformation of a daughter so far down a troubled path, similar to that of her killers, that her youth pastor thought she might be beyond saving.[pullquote]When the Bernalls found Cassie’s letters talking of disemboweling her parents, together with signs of satanic activity, they acted decisively.They did so in ways that would horrify those who speak glibly of children’s rights: a court order preventing contact with friends, enrollment in a private (Christian) high school, repeated searches of Cassie’s room and backpack, monitored telephone calls, no leaving the house without permission. And they stood firm in the face of Cassie’s hatred and contempt and pressure from her friends and even other parents. Then, at her new school, Cassie found a new friend, as eccentric in dress and hairstyle as she was. She showed Cassie some truths about herself, and took her on a teen retreat where she had a conversion experience and began working out her new faith in a changed life. This is a frightening book for parents: knowing incidents like the ones in Littleton or Taber, Alta., could happen anywhere, and facing the truth that no matter how conscientious they try to be, their kid could also go off the rails. Even more frightening, perhaps, could be the prospect of having to stop trying to be a buddy to one’s child and instead be the adult mentor ? in control. The young have begun to identify with this teenager who struggled with rebellion and peer pressure, made some bad choices and dangerous decisions, but who ultimately came to set her life straight and dedicate it to sharing what she’d found with others. The book also reinforces what Christians have known for 2,000 years, but too rarely practise: the most effective evangelist is not an authority figure but someone in your own peer group. The really important “Yes” for Cassie Bernall was the one she said, not to her killer, but to God ? during and after that life-changing retreat.