A Photojournalist Frank West was in a helicopter with a pilot,Ed DeLuca,and learned that the town is quarantined due to a Zombie Outbreak. He was later dropped off at the Mall.
He meets a researcher,Doctor Russell Barnaby,a Janitor,Otis Washington,a DHS Agent,Brad Garrison,and his partner,Jessica McCarney. Frank begun searching for more survivors as the Mall is breached. Brad warns him about the Zombies aren't the only ones,but psychotic survivors as well.
Frank sees a woman being held captive by a mad manager,Steve. After Frank kills Steve,the Woman introduce herself as Isabela Keyes,sister of the unknown assailant,Carlito,and promised to set up an interview between the two.
Frank and Isabela are ambushed by Psychos,but manage to escape the Zombies attacks them. Isabela reveals that Santa Cabeza was home to an American research facility experimenting on cattle and that Barnaby was its head. Isabela,as a research assistant,was privy to the fact that a species of native wasp was used in an attempt to boost the performance of cattle,but instead had a zombifying effect. The wasps escaped and infected humans,forcing a U.S. military cleanup of all life in town,with few escapees. Barnaby begins to zombify and was killed by Brad.
While avoiding the Zombies,Jessie was killed by Carlito,who reveals that he'll be using bombs to destroy this place and has the psychos in hoping to kill Isabela.
Brad and Isabela disable the bombs while Frank and Carlito engaged in a shootout. Carlito is mortally wounded. A Psychotic Butcher,Larry appears and kills Carlito. Frank manages to kill Larry as Isabela shuts down the jammer. However,U.S. Special Forces arrive in the mall regardless,and have cleanup orders.
Otis,Brad,Frank,Isabela,and the survivors escapes in the helicopter. Later at the Military base,Frank was informed by DeLuca about a strange incident going on at the city caused by an unidentified Corporation.