In his new theory of suicidal behavior, Thomas Joiner proposes three factors that mark those most at risk of death: the feeling of being a burden on loved ones; the sense of isolation; and, perhaps chillingly, the learned ability to hurt oneself. He tests the theory against diverse facts taken from clinical anecdotes, history, literature, popular culture, anthropology, epidemiology, genetics, and neurobiology--facts about suicide rates among men and women; white and African-American men; anorexics, athletes, prostitutes, and physicians; members of cults, sports fans, and citizens of nations in crisis.