If aliens are among us, how have they impacted our world and how will people react to this discovery? From recent breaking news on the U.S. government's funding of UFO research to recently discovered hidden facts behind chambers in Egypt's Great Pyramid, each new episode covers various alien-related topics with historic detail, first-hand accounts and interviews with the world's top scientists, archaeologists and researchers.

Lead expert Giorgio Tsoukalos joins Ancient Astronaut theorists, David Hatcher Childress, William Henry, Linda Moulton Howe, Erich von Daniken and many others being interviewed, as this season travels to over a dozen countries to explore firsthand signs of ancient alien visitation. On the island of Sardinia, Italy, ancient statues of giants with alien features are shown to the public for the first time; hidden messages are uncovered in the artwork of Leonardo da Vinci and strange alien-looking statues are explored on the Marquesa islands of the South Pacific.