"Nightmare bacteria." That's how the CDC describes a frightening new threat spreading quickly in hospitals, communities, and across the globe. FRONTLINE reporter David Hoffman investigates the alarming rise of untreatable infections: from a young girl thrust onto life support in an Arizona hospital, to a young American infected in India who comes home to Seattle, and an uncontrollable outbreak at the nation's most prestigious hospital, where 18 patients were mysteriously infected and six died, despite frantic efforts to contain the killer bacteria. Fueled by decades of antibiotic overuse, the crisis has deepened as major drug companies, squeezed by Wall Street expectations, have abandoned the development of new antibiotics. Without swift action, the miracle age of antibiotics could be coming to an end.