After escaping from a chain gang, Luke (Jim Brown) partners with tough prospector Jaroo (Lee Van Cleef) to search for gold in a Mexican fort. The enterprising duo manage to convince Apache chief Santana (Iron Eyes Cody) and his tribe to help them infiltrate the fort, which is defended by Mexican military officer Chavez (Patrick O'Neal) and his men. While things don't go according to plan, Chavez's lover, Claudine (Mariana Hill), falls for Luke, which proves helpful to the scrappy bandits.