In 1925, British explorer Percy Fawcett entered the Amazon rainforest with his son and another young man, determined to find a mysterious lost city. None of them ever returned, and their disappearance sparked one of the greatest mysteries in exploration history. For decades, people assumed the men had met a terrible fate somewhere in the jungle. But nearly 80 years later, a researcher uncovered evidence suggesting something far stranger: Fawcett might have been planning to disappear all along.