The movie contains a good general overview of the subject in terms of sightings, cases, historical timelines, etc. Several personalities in the UFO community of the time make appearances; some, shall we say, more colorful than others. Various theories on UFO propulsion are forwarded. A segment on how planetary motion could be copied and modified to make a space vehicle which would act as a "freely navigating planet" is of particular interest (arguably, the best part of the movie). Also presented are special techniques for photographing UFOs, as well as alternative theories as to their origin and nature, i.e., flying critters in the atmosphere, as opposed to spacecraft. Go figure.
It is worth mentioning here that much of the footage from this movie is re-used from an earlier documentary from the same producers, called "UFO Journals", which, while good, seems less cohesively structured than the latter one, almost like a feature-length screen test. Both are worthwhile, but this one, in my estimation, is the better bet.