 Called by the Mexican President himself, and in spite of a heart condition, young teacher Rosaura Salazar (Felix) travels to the desertic town of Rio Escondido to accomplish the mission of bringing education to the poorest people. Being there, Salazar has to fight Regino Sandoval (Lopez Moctezuma) the evil landlord of the town. He has transformed the town into his own property, impossing his will and spreading death everywhere.