Armando Alvarez (Will Ferrell) has lived and worked on his fathers ranch in Mexico his entire life. As the ranch encounters financial difficulties, Armandos younger brother Raul (Diego Luna), shows up with his new fiance, Sonia (Genesis Rodriguez). It seems that Rauls success as an international businessman means the ranchs troubles are over as he pledges to settle all debts his father has incurred. But when Armando falls for Sonia, and Rauls business dealings turn out to be less than legit, all hell breaks loose as they find themselves in a war with Mexicos most feared drug lord, the mighty Onza (Gael Garcia Bernal)