One of the biggest investigations in medical history began when a mysterious killer disease broke out during independence celebrations in Philadelphia in 1976: Legionnaire's Disease. NOVA traces the search for a cause and cure—a search bedeviled by false trails, accusations of incompetence and cover-up, and increasing urgency as the death toll mounted.

NOVA explores the past, present, and future of American television including the potential of cable, the Columbus, Ohio, two-way TV experiment, the array of new techniques and their potential social impact. Will the new video technology let people see what they really want, rather than what the networks want?