Alice is a carrier who has a genetic immunity to the extreme effects of the infection. Don, unfortunately, does not.

Scarlet and Doyle try to get Andy and Tammy out because they may be immune from infection.

The army tries to contain an outbreak of infected maniacs.

When infection gets out of control, the army calls in an airstrike.

A young boy takes refuge with a group of strangers that has hidden in a cottage when the infected attack.