Mutant snakes survived a terrorist attack on a government laboratory, and they now threaten the town of Santa Mira Springs, California. Seismic activity has brought snakes to the surface, where residents are being bitten. Victims can transmit the virus to healthy persons. The military puts the town under quarantine. Local physicians try to control the epidemic, while the military is primarily concerned with keeping the virus a secret.

The story of an inner-city Los Angeles police precinct where some of the cops aren't above breaking the rules or working against their associates to both keep the streets safe and their self-interests intact.