Serial 5T:
The Keeper Of Traken

Starring: Tom Baker (The Fourth Doctor), Matthew Waterhouse (Adric), Sarah Sutton (Nyssa). 
The Union of Traken is governed by a Keeper gifted with the powers of the Source. The current Keeper is nearing the end of his thousand-year tenure, however, and asks the Doctor and Adric -- now back in our own universe of N-Space -- to go to Traken and stop an evi
l he believes is plotting to destroy the Union. The source of the evil, the Melkur, has already infiltrated the Consuls of Traken, however, and has the Doctor declared a criminal. Allying himself with Consul Tremas and his daughter, Nyssa, the Time Lord must uncover the true power behind the Melkur -- someone who knows the Doctor of old.

For years, To
m Baker had dropped hints about leaving Doctor Who. Every time, though, he ended up backtracking and sticking with the programme, to the point that by 1980 he was the show's longest-running star, beating out William Hartnell for total episodes and Jon Pertwee for the most seasons. But by the autumn of 1980, those hints had finally become a reality: Baker would be leaving Doctor Who at the end of Season Eighteen, after seven seasons and 180 episodes (counting the incomplete Shada). On October 24th, after it was learned the story had been leaked to the Daily Mirror, the BBC hurriedly arranged a press conference to announce the impending departure.

Meanwhile, scrip
t editor Christopher Bidmead had been working with Johnny Byrne to craft Baker's penultimate story. Byrne had both written and scripted-edited the short-lived science-fiction drama Space: 1999, and had also written for All Creatures Great And Small where he met new Who producer John Nathan-Turner. Byrne had been approached to write for Doctor Who by both Robert Holmes and Douglas Adams, with nothing resulting from either invitation. He had also been offered the post of script editor by Nathan-Turner prior to Bidmead's hiring, but had turned down the job because he did not want to move to London from Norfolk. When approached by Bidmead about writing a Doctor Who serial, Byrne was once again interested and soon devised a storyline entitled The Keeper Of Traken.

The version of the ser
ial commissioned from Byrne around early June differed from the broadcast version in some notable respects. Most significantly, Byrne's villain was a megalomaniac called Mogen, an outcast from an extinct galactic power. Byrne also divided Trakenite society into two groups -- the scientific Greys and the zealous Blacks, led by Hellas and Zorca, respectively. With Baker's decision to leave Doctor Who, however, Nathan-Turner and Bidmead decided that they needed to carefully structure the end of Season Eighteen and the start of Season Nineteen, fearing that the departure of such a popular and long-running Doctor would adversely affect the ratings. It was decided to link the last two stories of the current season and the subsequent season premiere into a loose trilogy.

The common elemen
t would be a new incarnation the Master, the Doctor's Time Lord archnemesis who had been a key figure during the Pertwee era. The Master's time on the programme had come to an end with the tragic death of actor Roger Delgado; an effort by the former production team of Philip Hinchcliffe and Robert Holmes to reintroduce the Master in an emaciated, skeletal form in 1976's The Deadly Assassin had never been followed up on. Nathan-Turner wanted to bring back the essence of the Master's original appearance. Consequently, it was decided that The Keeper Of Traken would chronicle the Master's transformation from his cadaverous look. It was decided that the Master would replace Mogen in Byrne's original concept, although he would spend much of the story masquerading as a creature called the Melkur.

In August, not long after making these changes, Byrn
e left on vacation for Greece and gave Nathan-Turner and Bidmead permission to make any other changes to The Keeper Of Traken that they saw fit. Bidmead renamed the two principal supporting characters: Hellas became Tremas (an anagram of "Master", who would possess Tremas' body at the adventure's conclusion) and the male Zorca became the female Kassia. Bidmead also deleted the distinction between Blacks and Greys.

Cast to
play the new Master was Anthony Ainley, whom Nathan-Turner remembered as the evil Emelius in a 1974 BBC adaptation of The Pallisers; executive producer Barry Letts also knew Ainley, who played Sir Mulberry Hawk in Letts' 1977 version of Nicholas Nickleby. The actor also counted numerous theatre and film credits to his name, such as Oh! What A Lovely War and The Land That Time Forgot. Ainley, who had not seen Delgado's rendition of the character, was keen to inject humour into the character; however, this was vetoed by Nathan-Turner, who wanted the new Master to be more mirthless than the original. Ainley was given a twelve-episode contract, ensuring that he would appear throughout the planned trilogy.

Around the same time
, Nathan-Turner and Bidmead were working on a new female companion to be introduced in the season's final serial. However, one of Byrne's characters -- Tremas' daughter, Nyssa -- had caught their eye, in particular the strength of her relationship with Adric. It was felt that Nyssa might make another useful addition to the programme -- at least on a short-term basis -- to help ease the transition to the new Doctor. Although Nyssa would not join the TARDIS crew at the end of The Keeper Of Traken, permission was granted by Byrne to bring the character back in the next story, and possibly more beyond that. Bidmead worked to expand expand Byrne's ideas about the character; in the process, some early ideas -- such as her preternatural sensitivity -- were lost.

The actress chosen to play
Nyssa was Sarah Sutton, who had starred in a BBC adaptation of Alice In Wonderland and more recently in the supernatural drama The Moon Stallion (written by former Doctor Who scripter Brian Hayles). By October 12th, Sutton had been contracted for the remainder of Season Eighteen and the first eight episodes of Season Nineteen. This contract also included an option for a further sixteen of twenty episodes (later amended to sixteen of eighteen to correspond with the eventual length of Season Nineteen). Sutton was unveiled to the press on January 31st, 1981.

The director chosen for The Keeper Of Traken w
as John Black, a recent BBC appointee who had previously worked on three episodes of Softly, Softly: Task Force. Serial 5T would be a studio-bound affair, with work scheduled for two three-day blocks, the first beginning on Wednesday, November 5th and the second on Friday the 21st. Because Ainley would not begin playing the Master until the end of the story (when Tremas' body is taken over), Geoffrey Beevers was hired to play the dying, wizened Master introduced in The Deadly Assassin; the costume used in that adventure was rescued from junking and spruced up for the new serial. Beevers, who was now mainly a voice artist, had earlier appeared in Doctor Who in the minor role of Private Johnson in The Ambassadors Of Death. He was also married to Caroline John, who had played the Doctor's companion Liz Shaw a decade earlier.

Recording proceeded
without major incident until the final day of shooting, on November 22nd. As had been the case toward the end of the past several seasons, Doctor Who was once again victimised by labour action at the BBC when a one-day "mini-strike" was called. With the entire day's recording lost, a remount was required. This was eventually scheduled for December 17th, in the middle of production on the final story of the Tom Baker era, Logopolis.