The Marginal

While investigating a kidnapping, a former policeman infiltrates a prison, where he must prevent dangerous criminals from discovering his true identity. In the first season, former policeman Miguel Palacios is imprisoned in San Onofre under a false name and a false court case. Their mission is to infiltrate a criminal gang of prisoners and prison guards and gather information about a judge's daughter kidnapped by the gang. The second season is a prequel that takes place three years before Miguel Palacios infiltrated San Onofre. Mario Borges and Juan Pablo "Diosito" Borges are sent to San Onofre, where they plan to overthrow the prison's leader, "El Sapo" Quiroga. To achieve this, they ally themselves with the "Sub-21" gang and with Patricio Salgado, a doctor with a mysterious past. In the third season, the Borges brothers are tasked with taking care of Cristian Pardo, the son of an important businessman, who killed his friend in a car accident while drunk. While Diosito takes care of the child, the "Sub-21" joins "Pantera" and Bruni to defeat the Borges.