ER follows the lives of the emergency room staff and doctors of Chicago's County General Hospital, a Level One Trauma Center where the difference between life and death rests on split-second decisions -- and the pressure, joy and guilt are often overwhelming. These medical professionals are determined to save lives in a place where nothing is taken for granted and nothing is certain ... nothing except that another desperate person will be rushed through the emergency room doors in the next moment, in need of their help. Some will live, and some will die, but the dedication and passion of these healers will endure.