On the planet Kembel, the Doctor meets Space Security Service agent Bret Vyon, who is searching for his missing colleague, Marc Cory. They learn that Cory was murdered by the Daleks, who have formed a vast intergalactic alliance -- of which Mavic Chen, the traitorous Guardian of the Solar System, is a member. The Daleks plan to use a time destructor to take over the universe, but the Doctor steals the taranium core needed to fuel it. The Doctor, Steven, Katarina and Bret are soon pursued across time and space by the Dalek forces... including Bret's own sister, fellow agent Sara Kingdom.

In the weeks leading up to Christmas 1964, The Dalek Invasion Of Earth had been a ratings goldmine for Doctor Who. At the time, a third Dalek serial, The Chase, was already being developed by writer Terry Nation for broadcast in May and June 1965. By late February, the possibility of a further six-part Dalek story was being discussed by Nation and producer Verity Lambert. It would air in November and December, in the hope of replicating the previous year's success. When the Doctor Who production office was allocated an extra episode at the end of its second recording block, it was agreed that this would be used as a one-off “trailer” for Nation's new story. This special episode, featuring none of the regular cast, would eventually become Mission To The Unknown.

On May 24th, Nation was commissioned to write a six-part story generically referred to as “The Daleks”. Two days later, a meeting of the BBC Programme Review Board was held to discuss, amongst other things, The Chase. The Controller of Programmes for BBC Television, Huw Wheldon, suggested that the Daleks' appearances in Doctor Who should be maximised. (Reputedly, this came upon the advice of his mother-in-law, whom Wheldon viewed as representative of the average viewer.) Wheldon was supported by Kenneth Adam, the Director of Television, who suggested that the next Dalek serial should be extended to thirteen episodes in length. Head of Drama Sydney Newman agreed to convey this message back to Lambert, via Head of Serials Donald Wilson.

A key obstacle to doubling the length of the Dalek story was Terry Nation's availability

In a May 28th reply to Wilson, Lambert noted that a key obstacle was Nation's availability, due to his commitments as the script supervisor on The Baron. She suggested that it would be possible to double the length of the next Dalek serial to twelve episodes, if outgoing Doctor Who story editor Dennis Spooner -- who was joining Nation on The Baron -- could be commissioned to write the final six episodes, based on an outline by Nation. This was deemed acceptable, and so Spooner and Nation were formally commissioned on July 5th and 16th, respectively. The development was greeted with some disappointment by new story editor Donald Tosh, since the length and timing of the Dalek epic would preclude him working with writers such as Hugh Whitemore (a playwright who had also contributed to shows like Compact) and Alex Miller (who had written an episode of No Hiding Place).

Nation's original, untitled outline differed from the finished product in numerous respects. The setting was the year AD 1,000,000 and the Daleks had established their base on the planet Varga. The “007 of space” met by the Doctor was called Brett Walton, the President of the Solar System was Banhoong, and Brett's traitorous friend on Earth was simply named Tom. It was the arrival of the Daleks on the “Devils Planet” (later christened Desperus) which sufficiently distracted the convicts to allow the Doctor and his friends to escape, and there was no mention of any criminals infiltrating the spaceship. Tom elected not to betray the Doctor's party and was murdered by the Daleks for helping them to escape to “the Planet of Mists” (eventually called Mira). The return of the Doctor and company to Varga happened at the start of episode ten. The sequences on Mira and in ancient Egypt drew upon ideas considered for The Chase.

One significant factor for which Nation's narrative had to account was the scheduling of part seven on Christmas Day. Because many viewers would be unable -- or unwilling -- to tune in that day, it was decided that the installment should be a comic interlude having little to do with the main plot. Recalling that Z Cars writer Keith Dewhurst had turned down his offer to write for Doctor Who, Tosh suggested that part of the storyline could be a spoof of the popular BBC crime drama. Nation and Spooner agreed to swap assignments on parts six and seven, enabling Nation to tackle the Christmas episode.

During the early summer, Lambert handed over the reins of Doctor Who to new producer John Wiles. Wiles, like Tosh, was unhappy to have inherited the sprawling Dalek story. He considered resigning over what he felt to be an imposition from the BBC brass that was out of line with his vision for Doctor Who, but Tosh persuaded him to remain. Wiles was able to secure an extra £3000 for the serial after complaining that the epic would be very costly to make; this effectively doubled the budget of the first two episodes. Wiles and Tosh hoped that the new story would allow the Daleks to be permanently retired.

Terry Nation was asked to kill off Katarina in episode four, and introduce a new female companion

Nation began writing his scripts for the companion team of Vicki and Steven Taylor. Late in the summer, however, he was informed that Vicki was being written out of Doctor Who in the preceding serial, The Myth Makers, to be replaced by Trojan handmaiden Katarina. However, Wiles and Tosh had concluded that Katarina was unsuitable as an ongoing companion, and so Nation was asked to kill her off in the fourth installment of the Dalek story. In the same episode, he was directed to introduce a new character who could fill the role of the female companion, at least for the remainder of the serial.

To this end, Nation developed Sara Kingdom, whom he envisaged as being a modern, aggressive woman in the vein of Cathy Gale, the character played by Honor Blackman in The Avengers. Sara was originally conceived as Brett Walton's lover, but they were later made siblings instead. Wiles and Tosh apparently gave some thought to retaining Sara beyond the Dalek serial, but they soon reconsidered and decided to have her die at the story's climax.

Various other changes were made as the scripts were being developed. Banhoong became Mavick (later, Mavic) Chen. The inhabitants of the Planet of Mists were first called Visilens; their final name of “Visians” was sometimes spelt “Visions”. The Technix were originally called Technocrats. Varga was renamed Kemble and then Kembel, although the name “Varga” would be retained for the Daleks' murderous plant life. The setting was brought forward to the year AD 4000. Several titles were ascribed to the serial; after briefly going by “Battle Of Wits”, it finally became The Daleks' Master Plan (with different documentation offering up a litany of minor variations).

As the summer wore on, Nation became more and more preoccupied with The Baron. According to Tosh, all of Nation's scripts were significantly underlength when they were submitted, although contemporaneous documentation suggests that this is an exaggeration. In particular, Tosh claimed that the Christmas episode originally clocked in at less than half the length of a typical Doctor Who script; amongst his revisions was the ending, which in Nation's version involved the Doctor inventing the cream-pie-in-the-face routine made famous in silent movies.

Spooner, meanwhile, decided to flesh out the Egyptian segment of the adventure by reintroducing the Monk. He had created the meddlesome time traveller for the previous season's The Time Meddler, and actor Peter Butterworth had made it known that he was keen to reprise the character. The Monk would appear in parts eight through ten of The Daleks' Master Plan, delaying the Doctor's return to Kembel until the eleventh installment. Spooner sought inspiration in history for the names of his Egyptian characters. These included Khepren (for Chephren or Khafre, builder of the second of the Great Pyramids of Giza), Hyksos (a Semitic-Asiatic tribe which invaded Egypt around the seventeenth century BC; the character was originally called Cerinus) and Tuthmos (for Tuthmosis or Thutmose, a name shared by four Egyptian kings).

Douglas Camfield and John Wiles gave great thought to the effect that the far-future setting might have on names

Although consideration was given to hiring two directors for The Daleks' Master Plan, the mammoth serial was ultimately assigned to Douglas Camfield alone. He had most recently handled The Time Meddler. Camfield and Wiles gave great thought to the adventure's far-future setting, and the effect that this might have on the names of people and places. Wiles sought Nation's agreement to modify the scripts accordingly; Nation consented, asking only that Mavic Chen and Sara Kingdom remain unaltered. The serial therefore saw the change of Brett Walton to Bret Vyon, Kurt Gantry to Kert Gantry, Reinmal to Roald, Gilson (originally male) to Lizan, Kirkland to Kirksen, Breton to Bors, Wingate to Garge, Carlton to Karlton, Barker to Borkar, Tom to Dexter and then Daxtar, Frayn to Froyn, and Bosworth to Rhynmal. Similarly, New Washington was changed to Communications Centre Earth. There was also concern that William Hartnell might have difficulty pronouncing “vitaranium”, the name Nation had coined for the crucial substance stolen by the Doctor. After VX2 and vita were rejected (the latter because Wiles feared it sounded too much like “vitamin”), it was decided to simply drop the first syllable and use the term taranium.

On September 8th, the role of Bret Vyon went to Nicholas Courtney. Earlier in the year, Courtney had been a candidate to play King Richard in The Crusade, also helmed by Camfield, and the director had not forgotten him. A few years later, Camfield would bring Courtney back to Doctor Who in a role which would become one of the most beloved and enduring in the programme's history: Brigadier Lethbridge-Stewart. Around September 14th, Camfield cast Jean Marsh -- who had played Richard's sister, Joanna, in the same serial -- as Sara Kingdom. Marsh was introduced to the press at a photocall on December 4th.

One of the concessions obtained for The Daleks' Master Plan was a week's delay to the start of studio recording, permitting Camfield's team to spend two weeks, rather than one, at the BBC Television Film Studios in Ealing, London. The Dalek casings available for this serial were the same four used in Mission To The Unknown. Amongst the work completed on the first day, September 27th, was Katarina's death scene -- ironically, Adrienne Hill's first performance for Doctor Who. The next day, Jean Marsh joined the production, principally for work on the fight scene involving the Egyptians. Effects sequences involving the Visians were the highlight of filming on the 28th, while the following day focussed on the activation of the time destructor in the final episode. The first week at Ealing then concluded on October 1st, which mainly dealt with the Daleks burning the jungle on Kembel.

Shawcraft Models informed John Wiles that they could no longer handle all of the work associated with Doctor Who

After the weekend, filming resumed on October 4th and 5th with the battle between the Daleks and the Egyptians. The remainder of the work at Ealing largely consisted of model shots, which were completed from the 6th to the 8th. Unfortunately, the film schedule endured a variety of delays, often due to problems with the props and models constructed by freelance firm Shawcraft Models. Shawcraft informed Wiles that they could no longer handle all of the work associated with Doctor Who, and indicated that they would not be averse to Wiles dividing it up between several companies. Amongst the model shots not completed at Ealing were those of the volcano on Tigus. As originally constructed by Shawcraft, it was out of scale with the miniature TARDIS. Further attempts were made on October 18th and 21st but, on both occasions, problems with the slow-motion film stymied Camfield's team. Finally, the shots were successfully obtained on November 15th.

The Daleks' Master Plan was recorded at BBC Television Centre in White City, London. Studio 3 was the venue for most episodes, the exceptions being episodes five and six, which used Studio 4. Part one, The Nightmare Begins, was taped on October 22nd, and the majority of the serial was scheduled for consecutive Fridays. Because of the one-week delay, Doctor Who was now recording only three weeks ahead of transmission. On October 25th, still photos of a model TARDIS were taken at Hammersmith Park in Hammersmith, London; these were for the cricket test match sequence in Volcano. The fourth installment, The Traitors, was taped on November 12th, and marked both Adrienne Hill's final work on Doctor Who as well as Jean Marsh's debut in the role of Sara Kingdom.

On November 19th, the same day that Counter Plot became the first of the two episodes recorded in TC4, Wiles was admonished by the Chief Designer for Drama, Barry Learoyd, who felt that insufficient time was being allotted for consultation between the director and the designer. As a means of averting this problem in the future, Learoyd suggested that no director should be permitted to handle more than six episodes at a time. In his reply of November 23rd, Wiles was sympathetic and extended his gratitude to the design team..

The Feast Of Steven was recorded on December 3rd. Camfield had approached Z Cars producer David Rose for permission to use the programme's police station set and to hire series stars Colin Welland (PC David Graham), Joseph Brady (PC “Jock” Weir), James Ellis (PC Bert Lynch) and Brian Blessed (PC “Fancy” Smith). Rose refused, however, expressing discomfort with the notion of his serious drama being associated with such light-hearted farce; the castmembers in question would also be busy with the new season of Z Cars during the week that The Feast Of Steven would be in production. As a result, Camfield decided to hire new actors to play analogous roles. He also cast his wife, Sheila Dunn, to play silent film heroine Blossom Lefavre.

John Wiles and Donald Tosh greatly disliked the Doctor's “fourth wall”-breaking Christmas greeting

An unusual element of The Feast Of Steven was the Doctor's Christmas greeting to the audience at home, which immediately preceded the closing credits. Wiles and Tosh greatly disliked this breaking of television's “fourth wall”. They would later claim that it was an unplanned ad-lib by Hartnell, but its inclusion in Camfield's camera script suggests otherwise. Due to the holidays, Doctor Who was not in the studio on Friday, December 24th; this would push the gap between recording and transmission to just two weeks. On December 27th, Camfield's team returned to Ealing to film more special effects sequences involving the Time Destructor.

Throughout the production of The Daleks' Master Plan, the already fragile relationship between Hartnell and Wiles degenerated further, a situation exacerbated by the deteriorating state of the star's health. Wiles was becoming increasingly exasperated by Hartnell's tendency to deviate from his scripted lines. The star's volatile temper also sparked a brief crew strike, arising from a dispute between Hartnell and his dresser. Things got so bad that, during the month of December, several newspaper reports claimed that Hartnell would be quitting Doctor Who.

However, as 1966 began, it was Wiles who wound up submitting his resignation. Never entirely comfortable as a producer, he felt burned out by the gruelling schedule imposed on him by The Daleks' Master Plan, and he was weary of his ongoing battles with Hartnell. Indeed, Wiles had suggested introducing a new actor to play the Doctor at the end of The Celestial Toymaker, but this scheme was vetoed by new Head of Serials Gerald Savory. Wiles would be replaced by Innes Lloyd; Lloyd accepted the job only reluctantly, as he harboured little interest in science-fiction. Tosh also decided to leave Doctor Who, not only as an act of loyalty to Wiles, but also because he was eager to try his hand at other material. Tosh also felt that he and Lloyd had incompatible visions for Doctor Who. Tosh's successor would be Gerry Davis, who had asked to be moved to a London-based series following an assignment on United!.

Meanwhile, for unknown reasons, the Doctor was removed from a large portion of the penultimate episode, The Abandoned Planet, shortly before it went before the cameras. Instead, Steven was assigned many of the Doctor's lines, while his own were split between himself and Sara. The Doctor now disappeared shortly after the TARDIS materialised on Kembel, and reappeared suddenly in the underground Dalek base near the start of Destruction Of Time. It was an exhausted cast and crew who recorded this last episode of The Daleks' Master Plan on January 14th, finally bringing the torturous production schedule to an end. The day also marked the conclusion of Jean Marsh's short tenure as a Doctor Who companion. The character of Sara Kingdom, meanwhile, would be revived by Nation for The Destroyers, the pilot script for his unrealised Dalek TV series.

Part 12 was trimmed when portions of Sara's death scene were deemed unsuitable

No fewer than three of the twelve episodes comprising The Daleks' Master Plan underran their allotted timeslot. Wiles claimed that part one, The Nightmare Begins, was short because of the difficulty encountered in accurately timing the special effects shots. He indicated that part ten, Escape Switch, was abbreviated because “a cast member” (presumably Hartnell) had omitted some of his dialogue, although this claim is not borne out by the camera scripts. Finally, he noted that part twelve, Destruction Of Time, had to be trimmed when portions of Sara's death scene were deemed unsuitable for the programme's audience.

Most episodes of The Daleks' Master Plan were broadcast as part of the same Saturday evening schedule as recent episodes, coming after Juke Box Jury and a news update, and before The Munsters. However, the shenanigans of Herman Munster and his clan were absent on November 13th (when The Nightmare Begins aired) and were removed from the schedules as of January 15th (when Escape Switch, was transmitted). For these four installments, Doctor Who was instead immediately followed by Dixon Of Dock Green, which otherwise aired after The Munsters. A significant exception was Christmas Day 1965, when the entire BBC1 schedule was -- unsurprisingly -- upended. On this day, The Feast of Steven aired in a later 6.35pm timeslot. It was preceded by the pantomime Mother Goose (with Jon Pertwee, the future Third Doctor, as the Squire), a news update and an appeal by Val Doonican on behalf of family service units, and it led into Max Bygraves Meets The Black And White Minstrels.

Meanwhile, the December 11th broadcast of the fifth installment, Counter Plot, attracted some unexpected attention. Several days later, Camfield was contacted by the production office for Stanley Kubrick's landmark science-fiction movie 2001: A Space Odyssey, which would shortly go before the cameras. The filmmakers' enquiries involved effects sequences for the episode, notably the processes Camfield had employed to achieve both the bodies floating in space and the “molecular dissemination” effect.

• Doctor Who Magazine #272, 16th December 1998, “Archive: The Daleks' Master Plan” by Andrew Pixley, Panini UK Ltd.
• Doctor Who Magazine Special Edition #7, 12th May 2004, “I'm Into Something Good” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #6, 2017, “Story 21: The Daleks' Master Plan”, edited by Mark Wright, Hachette Partworks Ltd.
• Doctor Who: The Handbook: The First Doctor by David J Howe, Mark Stammers and Stephen James Walker (1994), Virgin Publishing.
• Doctor Who: The Sixties by David J Howe, Mark Stammers and Stephen James Walker (1992), Virgin Publishing.