Dangers of an influenza pandemic are explored in a fictional scenario that begins with a young Hong Kong businesswoman being sneezed upon by a butcher who had cut up an infected pig. As the hour traces the history of influenza back some 4500 years, it tracks the progression of the virus in “patient zero,” and the virus's transmission around the world. She infects 13 people on a flight to London, and 43 million are sick within a week.