Río Negro is the struggle of two men, Osuna and Funes, hungry for power and wealth in a small town in Venezuela, during the dictatorship of Juan Vicente Gómez
Anita Camacho, an ambitious maid poses as the owner of the house where she works in order to seduce a man of money, marry him and finally stop being poor.
Commissioner Leon (Miguel Angel Landa) of the Technical Judicial Police is assigned to the kidnapping of a child of the upper class of Caracas. The details of the kidnapping the attention of Leon, as there is no evidence of violence in the child's home, or witnesses to the abduction. Based on that Leon believes that the hijackers knew the boy and soon begins to suspect several young people from wealthy families of Caracas.
Happy fun times with a little crew of people driving around to backwater villages to show movies in places where the locals don't get much culture. But all good things come to an end...
A naive but humane student leaves his town with the ambition to become a doctor, promising to return to help his people, who see him as a local hero.