A naïve rookie in the Mexican highway patrol must adapt in order to survive as he contends with widespread corruption, dangerous drug runners and the consequences of his often morally gray actions.

Married small-time crooks Lou-Jean and Clovis Poplin lose their baby to the state of Texas and resolve to do whatever it takes to get him back. Lou-Jean gets Clovis out of jail, and the two steal their son from his foster home, in addition to taking a highway patrolman hostage. As a massive dragnet starts to pursue them across Texas, the couple become unlikely folk heroes and even start to bond with the captive policeman.