Finding plague victims inside their compound, survivors of the zombie apocalypse suspect that the zombie plague has mutated and is being spread by spores emitted by infected flesh-eating ghouls. People infected by the spores could be asymptomatic carriers. Not only do the survivors have to worry about being bitten by rampaging flesh-eating ghouls but also being infected by inhaling spores emitted by a carrier within their camp. Terrified and suspicious of each other, the victims live in mutual fear as they try to determine who the carriers are. A band of marauders takes over the compound and incites the members to turn against each other, exploiting their fear of carriers, as hordes of ghouls mount a devastating assault on the perimeter. Meanwhile, at the Mount Weather Emergency Operations Center President Cole declares a national emergency under section 201 of the National Emergencies Act and proclaims himself president for life as he hunkers down in the bunker with what little remains of the US government.