1970. The war in Vietnam is escalating. President Nixon has decided on a secret bombing campaign of Cambodia. He also declares a state of national emergency, and authorises Federal authorities, without reference to Congress, to detain persons judged to be 'a risk to internal security'. In a desert zone in southwest California, a civilian tribunal passes sentence on groups of dissidents and gives them the option of participating in law enforcement training exercises in the Bear Mountain Punishment Park. In an atmosphere of aggression, intimidation and soaring temperatures, the prisoners have to fight for their lives as they are hunted down buy the forces of law and order.