<span class="SFPTagline"> From SCIFIPEDIA </span>

For Doctor Who, Season Sixteen, producer Graham Williams wanted to include a frame story that would emcompass the entire season. The story would eventually become known as "The Key to Time." At the start of the season, the Doctor would be contacted by The White Guardian, the embodiment of goodness and light (on screen, this entity's portrayal would have distinct religious overtones). The Guardian would require the Doctor to locate and assemble the six segments of The Key to Time, an artifact the guardian needed to restore order to the universe. Each of the season's stories would be concerned with the serach for a single segment.

To this end, The Gaurdian would assign the Doctor a new companion in the form of haughty young Time Lady Romanadvoratralundar (a.k.a. Romana). Actress Mary Tamm would eventually be cast in the role.

Realizing this vision, however, would prove almost as problematic as had the previous season. Due to the problems with the previous season, the time available to assemble scripts for this season was significantly reduced. Script editor Anthony Read hired several individuals to write scripts, among them former Doctor Who script editor Robert Holmes and future celebrity Douglas Adams. Adams was, however, becoming a busy man, both as the producer of Radio 4's Week Ending and writing a radio serial he intended to call The Hitchhiker's Guide to the Galaxy. He was slow to complete his script.

Another writer that had been contracted ended up having difficulties completing his script due to a recent divorce and a resulting bout of alcoholism. Robert Holmes had to be brought in to author a second story at the last minute. Furthermore, the scripts for both "The Pirate Planet" and "The Armegeddon Factor" required extensive rewrites by Read because they could not be done on the program's increasingly limited budget and Read was forced to substitute for Williams as producer after Williams suffered an accident while on vacation. An exhausted Read would resign at the end of the season.

Moreover, the bickering between unions about who should perform various tasks that had nearly resulted in the abandonment of the previous season's closer, "The Invasion of Time", would continue to plague the production this year, causing the loss of some special effects in "The Ribos Operation" and some serious delays in recording "The Armegeddon Factor."

Nevertheless, the season was once again completed successfully. Season Sixteen began airing on September 2, 1978.

• The Ribos Operation (4 episodes)
• The Pirate Planet (4 episodes)
• The Stones of Blood (4 episodes)
• The Andoids of Tara (4 episodes)
• The Power of Kroll (4 episodes)
• The Armegeddon Factor (6 episodes)