On a quiet and unannounced morning in Philadelphia, former United Nations investigator Gary Lane (Brad Pitt) drives his wife Karen (Mireille Enos) and two daughters Rachel (Abigail Hargrove) and Connie (Sterling Jerins) out in a car. Unexpectedly, the originally happy atmosphere was quickly replaced by panic and death. A series of explosions, panicked and fleeing crowds, disorderly car accidents and zombies gnawing at others, the prosperous metropolis fell in an instant. Gary made great efforts to escape with his wife and daughter, and finally escaped to the aircraft carrier where the United Nations Deputy Secretary-General was located. He then learned that several heads of major powers, including the President of the United States, had died and that the zombie virus had spread around the world. In order to prevent the world from being destroyed, Gerry was reluctantly ordered to go to the source of the virus with Faryes Gabel, a Ph. D. in virology from Harvard, to find a way to resolve the crisis. This is a journey that is almost completely hopeless and full of hardships, and the fate of the world is at stake...