Thousands of reliable witnesses including doctors, teachers, policemen, pilots, and high-ranking military officials have described encounters with alien craft and alien abduction. In fact sightings of mysterious craft in the sky and encounters with strange, nonhuman, extraterrestrial entities have been described for millennia. Cave paintings dated from 40,000 years ago show nonhuman beings that are often depicted with strange craft that are quite clearly not from this planet. After twenty years of research into the phenomenon I have found the evidence for its veracity to be both overwhelming and frightening.