On the hottest day of the summer, a Milwaukee nurse named Ana has just gotten off work to cuddle up with her husband, not paying any attention to an emergency broadcast involving a plague that is sweeping the nation. When her next door neighbor, a little girl, wanders into her bedroom, she sinks her teeth into the neck of Ana's husband Louis and no sooner does Louis die from blood trauma, he's back on his feet and trying to bite Ana. Taking off in her car, Ana watches in horror as the city becomes a virtual 'hellzone' as people begin to feed upon people, until she crashes her vehicle. Rescued by tough lawman Kenneth, Ana and a group of other survivors decide to hide out at the local Crossroads mall where they begin to learn through news broadcasts that the plague is turning civilians into primal, carnivorous cannibals with an insatiable hunger for human flesh and the only way to take these bad boys down is by shooting them in the head (which should terminate all brain activity). The group decides to hold up at the mall until a rescue team can come back and pick them up, but problems begin to arise when the infected start making their way toward the shopping center in search of more survivors.