To save humanity, the Earth's mightiest heroes must reunite for a rematch of heroic proportions.

When a Los Angeles bound passenger airline reports an inexplicable death mid-flight, Dr. Kayla Martin of the Center for Disease Control is called in to evaluate the frightening possibilities. She must determine if it is the reality of the bird flu, the probability of a biological attack or worse, a new virus that can't be contained. With the clock ticking and a search for Patient Zero commencing around the globe, the virus begins to spread, the body...