Through moving interviews with five ordinary people who rescued Jews during the Holocaust, Kristen Monroe casts new light on a question at the heart of ethics: Why do people risk their lives for strangers and what drives such moral choice? Monroe's analysis points not to traditional explanations--such as religion or reason--but to identity. The rescuers' perceptions of themselves in relation to others made their extraordinary acts spontaneous and left the rescuers no choice but to act. To turn away Jews was, for them, literally unimaginable. In the words of one German Czech rescuer, "The hand of compassion was faster than the calculus of reason."