Ed, Henry and Phil, three American college grads, road-trip south of the border in pursuit of a fun-filled weekend of drinking and debauchery. Instead, they find dismemberment and death in the world of predators hunting the dimly lit streets and dark alleys of Manzinita, Mexico in search of their next prey. The Mexican locals recently tortured and killed were strong and silent and did not cry out in pain. Instead, they need loud, terrified cries of an American to make the ritual stronger; one who will howl in agony as he looks into the face of death. They set their sites on the three American amigos, and the vacation across the border quickly becomes the trip from hell. The Americans hook up with some Mexican girls and after a night of partying with Lupe and Valeria, Ed and Henry realize Phil never made it back to the hotel. When the police refuse to do anything, they soon learn they are dealing with powerful and dangerous people. No one will help, until an ex-cop on the trail of the cult joins forces with them in the manhunt for the cult and their friend. But it may prove to be too late for all of them.