From the PDF:
An encrypted journal. A bloody assassination. A long-lost holy relic. Unraveling these mysteries will take explorers from the bustling streets of Rio de Janeiro to the deepest, darkest reaches of the Amazon jungle where even conquistadores feared to tread.
The clues point to the lost city of the Q'ero, rumored to be filled with riches beyond imagination-and a legendary holy artifact that could be used for either great good or terrible evil. But to get there, the explorers must first uncover an ancient conspiracy of murder, greed, and miraculous revelations.
The Miracle Stone of the Amazon can fit into your ongoing Hollow Earth Expedition game or serve as a jumbo-sized stand-alone scenario. It features optional new rules for Faith and Miracles, which provide players and Gamemasters new choices for supernatural powers.