UFO was Gerry and Sylvia Anderson's big opportunity to create a science fiction television series with live-action – as opposed to puppet – performers and it has been a cult favourite for decades. But when the series was first set to hit the screen, there was great concern behind the scenes about its dark and at times controversial subject matter. "The theme is sick," wrote one executive tasked with previewing episodes. In this documentary, we delve into the archives of the Independent Television Authority (ITA) to find out what those in power thought of the show before it had reached screens and what audience members made of it once they had a chance to see it. Letters from outraged parents, concerned doctors, and annoyed television executives all make appearances in this "points of view" style look at one of Century 21's most beloved productions. Was UFO obscene? Did the characters promote bad habits? Would viewers be able to cope with psychedelia before 8pm?