An American ex-marine, Lázaro Mendoza (Ignacio Serricchio) enters a maximum-security prison in Mexico (La Rotunda), under a false identity and accused of a supposed triple homicide. Now as Dante Pardo, his mission is to infiltrate a dangerous gang of prisoners and custodians that operates inside and outside the prison. They are the main suspects in the kidnapping of the teenage daughter of an American judge named John Morris (Guy Ecker). Within La Rotunda, Lázaro has to discover who is the mastermind of the kidnapping and find the whereabouts of the girl.
An adaptation of the Argentine television series titled El Marginal created by Sebastián Ortega and Adrián Caetano.