AllMovie

The golden arrow hits a mirror instead of Don Diego (Reed Hadley), but the would-be Yaqui assassin seems to have disappeared into thin air. Both Diego and Ramon (William Corson) suspect that the Indian may be hiding inside a water wagon destined for the San Mendolito mine. But mine-superintendent Gonzales (Edmund Cobb and the driver, Garcia (George Plues), feign ignorance and swear to the wagon's authenticity. Not convinced, our heroes follow the wagon to the mine but are told that Garcia only delivers water in the morning. Soon after leaving, they are attacked by a couple of Don del Oro's henchmen, one of whom, Martin (Ken Terrell), is killed in the ensuing struggle. The next morning, Diego discovers that the wagon indeed contains a secret compartment, which Don del Oro uses to smuggle weapons in his attempt to arm the Indians. But in a furious battle in the armory, Don Diego, as Zorro, is overpowered and imprisoned in the secret compartment of the water wagon. Ramon and the legion trail the wagon, which careens over a cliff into the raging river far below.