Intrigued by his experience, Greene decided to film a documentary movie about the UFO phenomenon.

[3] The film begins with a statement about its genre: "Many times in the history of our civilization the introduction of a new thought has brought skepticism, even ridicule.

The history of Project Sign, the first Air Force study of the UFO phenomenon, is discussed.

The documentary then focuses upon protagonist Albert M. Chop, who is assigned as the public information officer at Wright-Patterson Air Force Base in Dayton, Ohio, in the late 1940s.

In that position he is required to answer numerous news media queries about UFO sightings and what the Air Force knows about them.

The documentary concludes with the famous 1952 Washington, D.C. UFO incident, in which Albert Chop played a central role.

Tom Towers ... Albert M. (Al) Chop, U.S. Air Force press officer.

Floyd Burton ... Major Dewey Fournet, Project Blue Book's liaison at the Pentagon.

Robert Phillips ... U.S. Air Force Captain Edward Ruppelt, Project Blue Book Supervisor.