After a chemical plant explodes, the military quarantines the surrounding area. Jim helplessly watches his girlfriend Emilie die of a wound sustained while trying to find safety, and he retreats to a farmhouse. Sporadic media reports indicate that the chemical plant may have stored biological weapons that are responsible for mutating people into rabid cannibals. He seeks help from the ubiquitous military helicopters that patrol the area, but it is to no avail. However, his efforts are noticed by survivors holed up nearby in a warehouse, and he joins them: Scott, Scott's wife Julie, and Ix, a quiet and unfriendly survivor that they rescued.