In Guatemala, archaeologists identify an ancient site containing a series of unknown structures; a lake full of jellyfish is studied on a remote South Pacific island; Argentinian researchers discover a complex that may have a dark past.

On the island of Sri Lanka, archaeologists investigate an ancient structure built on granite columns above the rain forest; bizarre stone spheres are discovered in Costa Rica; the curious remains of a small man are found in Chiapas, Mexico.

On the island of Madagascar, paleontologists discover an intact fossil unlike any known animal, living or extinct. Also, bizarre stone spheres are discovered in Costa Rica and the curious remains of a small man are found in Chiapas, Mexico.