Three-part documentary in which scientists and experts give their opinions on the existence of extraterrestrials. In Part 1, astronomer Dr. Seth Shostak, of SETI (Search for Extra Terrestrial Intelligence), lays out the scientific facts about the possibilities and probabilities of extraterrestrial life; Dan Goldin, Director of NASA, describes the agency's position on extraterrestrial life, as well as UFOs; and Story Musgrave, NASA's most traveled astronaut, describes why he's convinced that extraterrestrials exist. In Part 2, Professor Leon Brenig of Brussels University and physics professor August Meesen of the University of Leuven in Belgium reveal their findings regarding UFO sightings by airplane pilots around the world. In Part 3, physical evidence of alleged UFO landings and crashes is examined.