Stanley Kubrick spent four years building 2001: A Space Odyssey, and this Channel 4 documentary traces how a science fiction film became one of cinema's most argued-over works. It covers the collaboration between Kubrick and Arthur C. Clarke, who developed the novel alongside the screenplay from Clarke's short story The Sentinel, and the casting of Keir Dullea and Gary Lockwood as the astronauts sent toward Jupiter chasing a signal from a lunar monolith. Douglas Rain's voice work as HAL 9000 gets attention as one of the film's defining choices, a machine performance built entirely from vocal delivery with no face to act against. The film traces how Kubrick's technical demands, on effects, sets, and pacing, produced a picture that critics and audiences at the time did not know how to classify, and how it settled over decades into the status of an epic. Interviews and archival material fill in a production history that the finished film, deliberately opaque about its own meaning, never explains on screen.