For decades, legendary archeologist Dr. Johan Reinhard has been searching for the lost temples of the Inca Empire in Peru, but one has remained hidden: Ausangate, named after one of the most sacred mountains in the Empire. In 2011, environmental scientist Preston Sowell picked up where Dr Reinhard left off: While looking for threatened high-altitude species in the Peruvian Andes, Sowell discovered ruins and artifacts submerged beneath the waters of a remote lake at the headwaters of the Amazon River that he thinks are the lost temple of Ausangate. Featuring Dr. Reinhard, this film follows Sowell’s journey of discovery, loss and adventure as he seeks to prove the cultural significance of this sacred place in order to protect the lake’s watershed from environmental devastation.