UFO sightings enter American popular culture on June 24, 1947, when pilot Kenneth Arnold reports nine disc-shaped objects skimming past Mount Rainier and reporter Bill Bequette coins the phrase "flying saucer" to describe them. Two weeks later the Roswell Daily Record runs the headline "Army Air Force Captures Flying Disc in Roswell Region," and the film uses both cases as the starting point for a wider survey of the phenomenon. It moves through decades of reported encounters, government responses, and the U.S. Air Force's Project Blue Book, which reviewed thousands of sightings between 1952 and 1969 and closed most as aircraft, weather, or misidentification while leaving a residue of unexplained cases. Researchers, eyewitnesses, and skeptics each get time to make their case, and the film tracks how declassified documents and, more recently, social media have kept the debate active rather than settling it. The through-line is the same argument that started with Arnold: whether these reports point to something real in the sky or something in how people process the unfamiliar.