Forensic geologist Scott Wolter dives into one of North America’s most baffling mysteries: are there Aztec pyramids hidden at the bottom of a Wisconsin lake? Following legends of a “lost homeland” in the north, Scott uses a one-man submarine to search the murky depths of Rock Lake for ancient stone structures and the mythical “Rocky” lake monster. From suppressed 19th-century maps to the fortified ruins of Aztalan, we investigate whether the Aztec Empire actually began in the United States.