In the Old West, a gunfighter punishes the wrongdoers making justice himself, but his mother's words continue to fill his mind: "Justice is divine". Nonetheless, he goes on hanging the culprits, becoming quite famous. When a bunch of outlaws lead by a crooked landlord treats an innocent village and a beautiful girl, the time for the avenger's final mission is arrived.

"El Tarzan" Lira is an ex-convict who decides to give up his criminal past and reform his life. However, a corrupt policeman blackmails him leaving "El Tarzan" no other option but to continue committing robberies. Adapting the genre conventions of the film noir to the Mexican context, Ripstein's film focuses on Mexican police corruption and questions the judicial system.