NOVA probes the realities and public health policy implications of a terrorist attack on a major city using a radioactive "dirty bomb."

Few people know what a "dirty bomb" really is or what devastation it would cause. In this important and timely film, NOVA goes beyond the alarming headlines to answer crucial questions: how easy is it to acquire materials and manufacture a "dirty bomb?" How does it differ from a conventional nuclear one, and how destructive would it be? And how can lives be saved if one should explode? The program dramatizes two credible attack scenarios based on sophisticated models developed by radiation experts. These models are then played out in two major cities, Washington and London, with results that are both frightening and sobering.