The Trial of A Time Lord - Production

Production

The serial was proposed in 1985, after executive producer John Nathan-Turner and script editor Eric Saward learned that the twenty-third season would be postponed from January 1986 to September 1986. In addition to the delay, the run-times of the episodes ordered were reduced from forty-five minutes to twenty-five. Nathan-Turner and Saward realised that the new season would need a more creative format and scrapped planned serials, focusing instead on a trial story with an A Christmas Carol-inspired "past, present, and future" storyline, thereby stretching the length of the season. By July 1985, the characters of the Valeyard, the Inquisitor, and Mel were conceived.

Robert Holmes was commissioned to write the first and final chapters of the serial. His draft of the first chapter, The Mysterious Planet, was criticised by BBC Head of Drama Jonathan Powell for its comedic content, contradicting the BBC controller’s request for a more humorous series.

The second chapter, Mindwarp, was written by Philip Martin. Martin's character Sil, introduced in Vengeance on Varos, was popular among the production team, who asked Martin to feature the character in another serial. Nathan-Turner asked Martin to include Sil in his chapter, and asked for Peri to be killed in accordance with Nicola Bryant’s wishes to leave the show.

The third chapter was to be interlinked with the fourth. Holmes was originally asked to write it, but declined, citing a dislike of six-part serials. After rejecting submissions by Christopher H. Bidmead and PJ Hammond, Nathan-Turner approached husband-and-wife writing team Pip and Jane Baker to write a studio-based serial, Terror of the Vervoids.

Holmes was unable to finish writing the fourth chapter, originally called Time Inc., before his death from liver failure on 24 May 1986. Pip and Jane Baker were commissioned by Nathan-Turner at short notice to write a new version of the episode, after series script editor Eric Saward withdrew his permission for his original version of part fourteen to be used: the original ending would have featured a fight to the death in a time vent with both the Doctor and the Valeyard, which executive producer John Nathan-Turner did not want to use as such a downbeat ending would have provided an excuse for BBC management to cancel the show. Subsequently the title was later changed to The Ultimate Foe.

Filming of the serial began on 7 April 1986 and ended on 14 August 1986. For the opening sequence, Nathan-Turner commissioned a 45-second model shot that cost over GB£8,000, which at that time was the highest amount of money spent on a single special effects sequence in the history of the series. The outdoor sequences in The Mysterious Planet were filmed in mid-April in Queen Elizabeth Country Park, and studio work followed on 24 April and 10 May. Studio work for Mindwarp took place from 27–29 May and 11–13 June, and location shots were filmed in Brighton from 15–16 June. Terror of the Vervoids and The Ultimate Foe were produced simultaneously; production began with location filming for the latter in late June, before returning to the studio to film scenes for both chapters on 16–17 July. Terror of the Vervoids was the last chapter to be completed, with studio work taking place from 30 July–1 August and from 12–14 August.