The modern myth of the UFO is examined, beginning with the hysteria created by Orson Welles’s 1938 radio adaptation of H.G. Wells’s “War of the Worlds” and moving on to Kenneth Arnold’s 1947 sighting; the Roswell, New Mexico sighting later that year; the “contactee” movement of the 1950s; the abduction stories that began in the 1960s with Barney and Betty Hill; the photographs and the movie and video footage that purport to show alien spacecraft; and the crop circles that began appearing in the 1970s. Interviewees include eyewitnesses, researchers, authors and other believers in the myth, as well as a folklorist, a neuroscientist and other skeptics, who think there are cultural, geological and physiological explanations for the sightings. The documentary reaches back into the late-19th century to examine the sightings of air ships and back further to the Middle Ages to look at sightings of angels, demons, succubi, fairies, leprechauns and other creatures of fantasy.