Rene Cardona directs the film version of Jose Leon Sanchez's best-selling novel, which relates the author's 20 years of imprisonment on an island ruled by brutality. When a sadistic man declares himself the boss of an island pueblo, an innocent husband and wife become the victims of his selfish rule. Once the evil man's deeds reach the authorities on the mainland, however, he sinks further into madness and declares "his" island its own republic.

A group of teenagers drive out into the desert in search of sex, beer, and general good times. When their van breaks down, they find a group of prospectors who welcome the kids and offer them a place to stay until they can get help. It soon becomes evident, however, that there is more to these prospectors than they claim, and soon the teens are fleeing for their lives.

In 1909, former judge Cristóbal Zamarripa owns Valle Nacional, a tobacco plantation where he exploits workers with the support of the tyrant Porfirio Díaz, who sends him political prisoners as slaves. The others are lured with the promise of high wages, but end up owing everything to the company store. All are tortured, raped, or killed when they protest. Another landowner whose brother was killed by Zamarripa and who falls in love with one of his daughters is going to be punished, but he flees and becomes a revolutionary.

Conflicts in town force a guy to escape to a hiding-place in the countryside.