For five years, Jessica Stern interviewed extremist members of three religions around the world: Christians, Jews, and Muslims. She traveled extensively -- to refugee camps in Lebanon, to religious schools in Pakistan, to prisons in Amman, Ashqelon, and Pensacola -- and discovered that the Islamic jihadi in the mountains of Pakistan and the Christian fundamentalist bomber in Oklahoma have much in common. Based on her vast research, Stern lucidly explains how terrorist organizations are formed by opportunistic leaders who -- using religion as both motivation and justification -- recruit the disenfranchised. She depicts how moral fervor is transformed into sophisticated organizations that strive for money, power, or attention and suggests how terrorism might most effectively be countered.