Global silver trade from the 16th to 18th centuries which China desired, so they traded silver to make up for their trade deficit. The two most important mining colonies of the Spanish Empire were Peru and Mexico, who were estimated to have provided one-hundred thousand tons of silver from the mid 16th Century to the end of the colonial period. The richest, and most productive mine in the Americas was that of Potosí in what is modern day Bolivia. The richest camp in Mexico was in the city of Zacatecas, however the production of this mine was far less than that of Potosi. More simplistic native mining techniques dominated
The Robot vs. The Aztec Mummy in the production schedule. The evil Dr. Krupp (Luis Aceves Castañeda), a mad scientist known as "The Bat", managed to escape the snake pit into which he was thrown at the end of "The Curse of the Aztec Mummy" and continues his efforts in this film to steal a valuable Aztec treasure from the tomb of a centuries-old living mummy, Popoca (Angel di Stefani). Krupp builds a robot with a human brain in it, planning to use it to destroy the mummy, should he return to thwart his efforts. Krupp's former colleague and original finder of the mummy, Dr. Eduardo