Cockpit chatter and control tower audio form the spine of this History Channel special, which plays back recordings of pilots and astronauts describing objects they could not identify. It opens with the 1947 Kenneth Arnold sighting, the case that gave the phenomenon its name, then moves through decades of radar and radio traffic, including recordings from skies over New England and Texas and NASA footage and audio from 2005. Interviews cut between UCLA's Joseph Nagy, actor Ed Asner, and pilot and UFO researcher Don Berliner, each weighing what the recordings do and do not prove. The film treats the audio as primary evidence, letting listeners hear pilots' voices shift in real time as they try to describe something outside their training and instruments. Rather than settling on an explanation, it stacks case after case, from commercial cockpits to astronaut transmissions, and lets the pattern of similar reports across decades and locations make its own argument.