Melanie Bush and Sabalom Glitz suddenly appear at the Doctor's trial, summoned by the Master. He reveals that the proceedings are part of a conspiracy by the corrupt High Council of the Time Lords, who ravaged the Earth and renamed it Ravolox in order to hide the theft of Matrix secrets. Furthermore, the Valeyard is actually the distillation of the Doctor's evil side between his twelfth and final regeneration, and has been promised the Doctor's remaining lives. The Doctor pursues the Valeyard into the Matrix, where he must navigate the bewildering Fantasy Factory -- but the Master has plans of his own.

In mid-1985, Doctor Who producer John Nathan-Turner and script editor Eric Saward decided that the fourteen episodes of Season Twenty-Three would be tied together by the umbrella theme of the Doctor's trial by the Time Lords. The other principal architect of this concept was veteran Doctor Who writer Robert Holmes. At an early stage, it was hoped that he would write the season's first four-part segment, followed by the final six installments. But while Holmes was willing to write the introductory adventure, he was otherwise interested only in the last two episodes of the season, which would tie up the story arc. This arrangement was confirmed at a writers' meeting on July 9th.

Having completed the first four episodes of Season Twenty-Three under the title “The Mysterious Planet”, Holmes was commissioned to write the concluding two-part serial, “Time Inc”, on February 4th, 1986. On February 24th, however, BBC Head of Drama Jonathan Powell delivered a detailed and highly negative critique of “The Mysterious Planet”. Holmes, who was now in ill health, was greatly demoralised by Powell's comments, and was frustrated by the prospect of having to put “Time Inc” on hold while he revised “The Mysterious Planet”. Consequently, it was not until March that Holmes was able to begin work on the climactic scenario, now retitled “The Fantasy Factory”.

An early idea would have seen the Master revealed as the architect of the trial

An early idea for the season would have seen the Master revealed as the architect of the Doctor's trial. However, this denouement was deemed to be too obvious, and so it was agreed that the Valeyard would instead be unmasked as the true villain. The Master would still be involved in the narrative, however, and actor Anthony Ainley was duly contracted on April 1st. His last appearance had been in 1985's The Mark Of The Rani.

Holmes was asked to set much of the action of “The Fantasy Factory” in the virtual environment of the Matrix, which he had created for 1976's The Deadly Assassin. As such, the latter stages of the opening installment saw the Doctor encounter Bencray, the assistant to JJ Chambers at the Fantasy Factory, who was aware of -- and commented upon -- his artificial nature. The Doctor then encountered the Duke of Clarence and James Kenneth Stephen, who accused him of being Jack the Ripper; in reality, both men had been candidates for the infamous serial killer's true identity. At the episode's cliffhanger, the Doctor was thrown off a wharf by the Duke, and apparently drowned.

Although they consisted of two separate narratives, it was decided that the season's final six episodes would be made together as Serial 7C under director Chris Clough. As a result, some documentation now began to refer to the trial's last segment as the fifth and sixth parts of “The Ultimate Foe”, in reference to the working title which writers Pip and Jane Baker had devised for the previous segment. This nomenclature would become more closely associated with these two installments after the Bakers used it for their Target Books novelisation, published in 1988. The matter of titles ultimately became moot when Nathan-Turner opted to broadcast the entire season as The Trial Of A Time Lord. Holmes' scripts would therefore serve as Episodes Thirteen and Fourteen of this marathon adventure.

Sadly, Holmes was rushed to hospital around the end of March, where he would lapse into a coma. Shattered by this development, Saward agreed to take over the unfinished scripts. However, this new stressor exacerbated the ongoing breakdown in the relationship between producer and script editor and, on April 2nd, Saward resigned from Doctor Who. He nonetheless agreed to complete Holmes' work, on the condition that Nathan-Turner impose no large-scale changes to the storyline. Since the latter stages of Episode Thirteen were still in rough shape, Saward made a number of amendments to better lead into the concluding installment. He dropped the Jack the Ripper element, and replaced the Doctor's watery peril with the Valeyard's quicksand trap. Bencray was revised to become Mr Popplewick, whom Saward envisaged as a gaunt old man in the tradition of the miserly Ebenezer Scrooge, from Charles Dickens' 1843 novel A Christmas Carol. The Valeyard was established as the Doctor's final incarnation.

Eric Saward had the Doctor and the Valeyard plunge into the time vent, trapping the Doctor for all eternity

Scripting Episode Fourteen virtually from scratch, Saward began the proceedings with the Master saving the Doctor from the quicksand, while the Valeyard kidnapped Glitz. The Doctor encountered Popplewick again, who led him into a trap baited with an illusory Melanie Bush; here, Saward drew upon the audition piece he had written for the new companion. Popplewick was revealed to be a construct created by JJ Chambers, who was unmasked as the Valeyard. While news reached the courtroom of the High Council's mass resignation, the Master warned the Inquisitor that the Valeyard had materialised his TARDIS around a time vent in the Matrix. If the vent were to be opened for too long, there would be catastrophic ramifications for the space-time continuum. The Valeyard -- now shown to be a pitiable old man afraid of dying -- planned to use this threat to force the Time Lords to give him the Doctor's remaining regenerations. The Master revealed that he had been hired by the High Council to murder the Doctor in exchange for a pardon, but he had now decided not to follow through on his mission. The Doctor bluffed his way into the Valeyard's TARDIS just as the Valeyard opened the time vent door. Struggling, the Doctor and the Valeyard plunged into the time vent while the Master had Glitz seal the door, saving the universe but trapping the Doctor for all eternity.

Nathan-Turner, Saward and Holmes had agreed to end the season on such a dramatic cliffhanger in order to provide a memorable conclusion to what they knew might turn out to be Doctor Who's final season. It was inspired by the 1893 short story The Final Problem, in which Arthur Conan Doyle attempted to kill off his famed detective, Sherlock Holmes, by having him plunge into a gorge at the Reichenbach Falls in a struggle with the villainous Professor Moriarty. In mid-May, Saward was infuriated to learn that Nathan-Turner was now having misgivings about the downbeat ending. Nathan-Turner had grown concerned that it would provide the BBC with a tailor-made scenario to cancel Doctor Who, and he felt that the viewers who had followed the season for fourteen weeks were owed a genuine conclusion to the story. He also disliked the notion of the Valeyard being an evil future Doctor, since this could be seen as “wasting” one of the Doctor's lives; at that point, it was stipulated that a Time Lord could regenerate only twelve times. Furthermore, Nathan-Turner now wanted to reveal that former companion Peri Brown, who was seemingly killed off at the end of the second segment of The Trial Of A Time Lord, was alive after all.

Nathan-Turner and Saward corresponded in the hope of identifying a compromise which would assuage the producer's objections, while still respecting Holmes' original vision. These efforts proved futile, and Saward became concerned that Nathan-Turner would go ahead and alter the scripts as he saw fit. Furthermore, he had heard reports of Nathan-Turner badmouthing him to fans, and he was badly shaken by Holmes' death on May 24th. As such, on June 1st, Saward withdrew his permission for the use of his version of Episode Fourteen. He attempted to do the same for the portion of Episode Thirteen which he had written, but the BBC refused this request on the grounds that the work had been performed in Saward's capacity as a staff script editor. Consequently, the penultimate episode of The Trial Of A Time Lord would be the last on which Saward was credited.

John Nathan-Turner could not divulge any of the contents of Eric Saward's version of Episode 14

With the locations for the final two episodes of Season Twenty-Three already scouted, and rehearsals set to begin in less than two weeks, Nathan-Turner had to act quickly. He turned to Pip and Jane Baker, who had just written Episodes Nine to Twelve of The Trial Of A Time Lord at very short notice. On June 4th, Nathan-Turner despatched the script for Episode Thirteen to the Bakers via taxi. The next morning, he met with them at the Doctor Who production office. They were joined by a legal representative, who was responsible for ensuring that Nathan-Turner did not divulge any of the contents of Saward's version of Episode Fourteen. This meant that the Bakers had to come up with their own way of tying together all of the season's loose ends, without any knowledge of the original plan.

The new season finale was commissioned on June 6th. The Bakers delivered their reimagined storyline three days later, followed within a week by the completed script. Nathan-Turner acted as the script editor, and also made some changes to Episode Thirteen. It was at this stage that the Valeyard was redefined as an amalgamation of the Doctor's evil impulses from his own future, rather than his final incarnation. The time vent was replaced by the particle disseminator, and instead of the Valeyard being a weak man posing as JJ Chambers, he was now a much stronger figure masquerading as Mr Popplewick. The Master was given a more overtly villainous role, as opposed to the almost anti-heroic portrayal planned by Holmes and Saward, while the involvement of the Keeper of the Matrix was significantly reduced, much to the disappointment of actor James Bree.

Of the six episodes which made up Serial 7C, only the last two required location filming, which preceded the studio work on the production calendar. As such, these installments would mark Bonnie Langford's first work as Melanie. First, though, material on the beach was staged in East Sussex on June 23rd and 24th, chiefly at Camber Sands in Camber. The beach hut which Clough's team had arranged to use as the Master's TARDIS, on the other hand, was situated at the Rye Harbour Nature Reserve in nearby Rye. Cast and crew arrived to find the hut locked tight, and the key with which they had been provided did not work. After obtaining the permission of the Harbour Authority, Clough had no other option but to break in. It was later learned that the Harbour Authority had actually sold the hut shortly before the shoot -- provoking an unhappy response from the actual owner, and a hasty apology from the BBC!

A nervous Langford then joined the cast at the Gladstone Pottery Museum in Longton, Staffordshire. Once a working ceramics factory, it served as the Fantasy Factory and the rest of the Victorian environment within the Matrix from June 30th to July 3rd. On the last day, smoke from the Valeyard's exploding quills set off the museum's alarm, prompting the arrival of the local fire brigade. July 4th was reserved as a stand-by day, but does not appear to have been required.

Production then concluded on July 16th and 17th at BBC Television Centre Studio 1 in White City, London. The first day concentrated on material in the Master's TARDIS, while the second day saw the use of the courtroom set for the last time. One of the Bakers' goals had been to incorporate its destruction, since they had loathed writing the trial scenes for Episodes Nine to Twelve. The end of the studio block also completed Lynda Bellingham and Michael Jayston's involvement in Doctor Who; neither the Inquisitor nor the Valeyard appeared in the remaining material from the story's third segment, which would be recorded over the following month.

Clough had been wary that the Bakers had over-written Episode Fourteen, with initial run-throughs suggesting that it was almost a quarter of an hour too long. Even with numerous cuts made in both rehearsals and post-production, it became clear that there was no way to edit Episode Fourteen down to the required twenty-five minutes without making the narrative totally incomprehensible. Instead, Nathan-Turner asked Powell to allocate the broadcast a thirty-minute timeslot. Apparently happy with the way Season Twenty-Three was shaping up, Powell agreed. The sense of goodwill towards Doctor Who was enhanced on August 19th, when the BBC confirmed that the show would be returning for its twenty-fourth season.

The early episodes of The Trial Of A Time Lord debuted to small audiences in September

However, any euphoria was muted when the early episodes of The Trial Of A Time Lord debuted to small audiences in September. The long break between seasons, potent opposition from American action import The A-Team, and an unexpectedly weak lead-in in the form of Roland Rat: The Series all contributed to viewing figures which fell below the disappointing ratings of Season Twenty-Two -- although the Appreciation Index, at least, saw some improvement. The first hint of imminent change came when the Controller of Programmes for BBC One, Michael Grade, met with Sydney Newman, the former Head of Drama who had spearheaded the creation of Doctor Who in 1963. Newman had written to the BBC on July 16th to enquire as to whether a credit might be added to Doctor Who which would identify him as its creator. Although the BBC rejected this request on September 3rd, Grade seized the opportunity to ask Newman to develop a complete revamp of Doctor Who.

On October 6th, Newman submitted a formal proposal to Grade's office. He suggested bringing back the Second Doctor, Patrick Troughton, to replace Colin Baker, with long-term plans of eventually regenerating the Doctor into a female form. The new companions would be a twelve-year-old trumpet player -- whose instrument could be used as a weapon, or to signal the Doctor -- and her eighteen-year-old brother, a graffiti artist who believed that the Doctor was out of touch. The Doctor would once again be unable to control the TARDIS, as had been the case during Doctor Who's early seasons, but Newman felt that the programme should rely less on adventures in outer space, and more on Earthbound narratives. Amongst his suggestions were stories set aboard a NASA space shuttle or a Polaris submarine, an encounter with Christopher Columbus, and a scenario in which the time travellers were miniaturised -- either examining the threat of DDT in an adventure similar to 1964's Planet Of Giants, or else fighting cancer cells in the body of a young patient.

Grade arranged a meeting between Newman and Powell, which went very poorly. This clash of personalities guaranteed that no further action would be taken on Newman's proposal as a whole. Nonetheless, one of his recommendations was taken up: by mid-October, Grade had decided to fire Baker from Doctor Who. In a meeting with Nathan-Turner on October 21st, Grade and Powell argued that three years was enough for a Doctor -- even though Baker had only completed two full seasons, and had harboured aspirations of breaking Tom Baker's seven-season record. Nathan-Turner was told that he would be moved off Doctor Who at the end of November if he agreed to break the news to his lead actor. Although he objected vociferously to his superiors' decision, Nathan-Turner was at least relieved that his own departure from the programme -- which he had been requesting for the past three years -- would finally come to pass.

On October 29th, Colin Baker was devastated to learn that his time as the Sixth Doctor had come to an end

On October 29th, Baker was devastated to learn from Nathan-Turner that his time as the Sixth Doctor had come to an abrupt and unceremonious end. He met with the Head of Drama on November 6th, but he was unsuccessful in changing Powell's mind. However, Baker was offered a contract for a final four-part adventure, which would climax with the Doctor's regeneration into his seventh incarnation; this was chiefly a result of Nathan-Turner's lobbying efforts. Langford fared better in the eyes of the BBC, and she was contracted for Season Twenty-Four on November 13th.

Meanwhile, Nathan-Turner was preparing himself for his exit from Doctor Who, and expected to be moved onto a soap opera. On November 28th, however, he was furious to learn from Powell that he was being kept on Doctor Who for another year after all. He would have to cast a new Doctor, recruit a new script editor, and develop fourteen scripts -- all with the start of production barely four months away. When Nathan-Turner protested at the impossibility of the situation, he was escorted out of Powell's office.

The Trial Of A Time Lord Episode Thirteen aired on November 29th. Due to the BBC's broadcast of the Royal Variety Performance later that night, Roland Rat: The Series was preempted and Doctor Who was brought forward to 5.20pm. This placed it after Grandstand and a news update, although it was still followed by The Noel Edmonds Late Late Breakfast Show. On December 6th, the extra-length Episode Fourteen finally brought The Trial Of A Time Lord -- and the era of the Sixth Doctor -- to its adjournment. The season finale of Roland Rat: The Series aired immediately beforehand, while a new run of Bob's Full House, starring Bob Monkhouse, premiered after Doctor Who. With holiday programming dominating Saturdays over the next several weeks, it wouldn't be until January 1987 that the timeslot obtained another regular occupant, in the form of Jim'll Fix It.

The first press rumblings about Baker's termination had emerged on November 29th, and the actor himself finally confirmed the news on December 18th. By this time, he had presented the BBC with a counter-proposal which would see him record a final, full season as the Doctor; otherwise, he feared that his continued attachment to Doctor Who would cost him too much work over the coming nine months. When the BBC refused, Baker walked away; he formally rejected the offer of a regeneration story on December 19th.

Any hope of finding a compromise between Baker and the BBC evaporated on January 6th, when The Sun published an extensive interview with the actor. Here, Baker expressed regret at his dismissal from Doctor Who, but he also spoke scathingly of Grade and the cowardly way he felt he had been treated. Although Doctor Who would return in 1987, it was now inevitable that there would be a new lead actor at its helm...

• Doctor Who Magazine Winter Special 1992, “Archive: The Ultimate Foe” by Andrew Pixley, Marvel Comics UK Ltd.
• Doctor Who Magazine Special Edition #3, 22nd January 2003, “It's Alright (Baby's Coming Back)” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #42, 2017, “Story 143: The Trial Of A Time Lord”, edited by John Ainsworth, Hachette Partworks Ltd.
• Doctor Who: The Eighties by David J Howe, Mark Stammers and Stephen James Walker (1996), Virgin Publishing.
• Doctor Who: The Handbook: The Sixth Doctor by David J Howe, Mark Stammers and Stephen James Walker (1993), Virgin Publishing.
• Doctor Who: The Trial Of A Time Lord DVD Production Subtitles by Richard Molesworth (2008), 2|entertain.
• The Essential Doctor Who #4, March 2015, “Time Inc” by Andrew Pixley, Panini UK Ltd.
• In·Vision #89, April 2000, “Production” edited by Anthony Brown, Cybermark Services.