Mariachi plunges headfirst into the dark border underworld when he follows a trail of blood to the last of the infamous Mexican drug lords, Bucho, for an action-packed, bullet-riddled showdown. With the help of his best friend and a beautiful bookstore owner, the Mariachi tracks Bucho, takes on his army of desperados, and leaves a trail of blood of his own.

El Mariachi just wants to play his guitar and carry on the family tradition. Unfortunately, the town he tries to find work in has another visitor, a killer who carries his guns in a guitar case. The drug lord and his henchmen mistake el Mariachi for the killer, Azul, and chase him around town trying to kill him and get his guitar case.