Bertie Bones, archaeologist, receives a secretive and mysterious phone-call from Salvador Gonzales a TV executive who has him travelling to Mexico, then across deserts and deep into the Sierra Madre mountains. Meeting some old friends and making some new Bertie gets caught up in a secretive and undercover expedition to search for the long lost gold of the Aztec emperor Montezuma. Things do not go exactly as planned though and Bertie finds himself...