Four survivors, Coach, Ellis, Nick, and Rochelle, find themselves abandoned on a hotel rooftop in Savannah, Georgia after rescue helicopters leave without them. In the aftermath of a pandemic known as the "Green Flu" that has turned the population into aggressive zombie-like creatures, the group must fight their way south toward New Orleans, rumored to be the last standing city in America.
Their journey takes them through a shopping mall, an abandoned amusement park, swamplands, and eventually the streets of New Orleans itself, where the military is conducting a final evacuation. Along the way, they rely on safe houses, improvised weapons, and each other to survive against increasingly dangerous hordes of the Infected.