For thousands of years, humankind has attempted to make contact with beings from beyond Earth. Now, in the 21st century, the search for extraterrestrial intelligence is ramping up like never before, with powerful new technologies allowing us to explore billions of stars across the universe. Are we on the verge of first contact?

Throughout ancient cultures there are stories of god-like beings providing instruction to early humans, helping our ancestors to establish the first civilizations and teaching them in various disciplines. Could it be true? And do mysterious figures who appear throughout history provide evidence that these otherworldly teachers have been with us all along?