When the TARDIS is stolen from Gatwick Airport, the Doctor and Jamie follow a trail of clues in an attempt to recover it, little realising that they're walking into a trap. Kidnapped by scientist Edward Waterfield, they're taken back in time to 1866. There they discover that Waterfield is the reluctant ally of the Daleks, who are holding his daughter, Victoria, hostage. The Daleks claim that they're trying to isolate the Human Factor -- that which makes mankind truly human -- and Jamie is compelled to endure a series of perilous trials to assist them. But the Doctor suspects that his old enemies have even more sinister motivations...

While the decision to have Patrick Troughton replace William Hartnell as the Doctor was undoubtedly the most consequential choice facing the Doctor Who production in 1966, a clear runner-up involved the future of the Daleks. This discussion had been galvanised by the development of The Power Of The Daleks as Troughton's debut adventure, and resulted in the suggestion by Dalek creator Terry Nation that they should be spun off into their own filmed adventure series. Nation submitted a formal proposal to the BBC on November 1st -- midway through the recording of The Power Of The Daleks -- which would showcase the Space Security Service and their top agent, Sara Kingdom, both of whom had been created by Nation for 1965's The Daleks' Master Plan. Sara would be joined by her brother, David Kingdom, as well as Captain Jason Corey and an android named Mark Seven. Nation provided a pilot script, entitled The Destroyers, and suggested a December 12th start to production.

Unfortunately for Nation, his proposal was rejected by the BBC on November 22nd. Consequently, Nation turned his attention to the American market, and tried to interest the National Broadcasting Company in the project. As a result, the BBC decided that Doctor Who's fourth season should end with a climactic showdown between the Doctor and his archenemies, whereupon the Daleks would be rested. As with The Power Of The Daleks, Nation was too busy to write the serial, but consented to David Whitaker doing so.

Originally, the Doctor travelled back to the year 20,000 BC and retrieved a caveman named Og

On January 4th, 1967, Whitaker submitted a brief outline of his proposed adventure, simply referred to as “Daleks”. At this stage, the Daleks' plan required the Doctor and Edward Waterfield to travel back to the year 20,000 BC to retrieve a caveman named Og. It was from Og that the Doctor was to deduce the essence of humanity, which the Daleks intended to eradicate from every generation of man, thereby eliminating the Earth as a threat. Meanwhile, Jamie and Victoria (whose name was an homage to the eldest daughter of story editor Gerry Davis) were held hostage on Skaro. Bob Hall was initially called Bill, and was a gangster. Anne Waterfield -- presumably Victoria's mother -- also appeared. By mid-January, the serial was known as “The Daleks”, but the title was fixed as The Evil Of The Daleks when Whitaker was formally commissioned on January 24th.

Around this time, Davis and producer Innes Lloyd decided to write companions Polly and Ben out of Doctor Who. Although Whitaker's original storyline had included them throughout the narrative, he was instructed to eliminate the pair from the final five installments, since Craze and Wills' contracts only ran to Episode Two. Whitaker was also asked to develop a female character who would be suitable as a new companion, and so Victoria's role was expanded. A similar request was made of David Ellis and Malcolm Hulke, who were writing the preceding serial, The Faceless Ones; this would provide the production team with a choice of characters. Lloyd and Davis subsequently decided that Ben and Polly would make their exit in The Faceless Ones instead, and so they were written out of The Evil Of The Daleks altogether.

The potential companion introduced in The Faceless Ones was Samantha Briggs, played by Pauline Collins. In mid-March, Collins indicated to Lloyd that she was not interested in an ongoing role on Doctor Who, which dictated that Victoria would instead be the new regular character. Auditions began in late March and, on April 10th, the part was offered to Denise Buckley, who had had a regular role in Emergency -- Ward 10 in 1965. However, plans soon changed and, the following day, Deborah Watling was cast instead. Watling had not participated in the auditions, but Davis recalled her from a 1965 Radio Times cover -- promoting an edition of the Wednesday Play in which she played Alice Liddell, muse to Lewis Carroll -- and suggested her to Lloyd. On April 17th, Watling was contracted for the final six episodes of The Evil Of The Daleks.

The director assigned to The Evil Of The Daleks was Derek Martinus, who had handled The Tenth Planet at the start of the current recording block. Four existing Dalek props were assembled by combining head and skirt sections retained from earlier serials. The company which had previously constructed new Dalek casings was Shawcraft Models, but a spate of problems had culminated in the decision to cease using their services for Doctor Who following the production of The Faceless Ones. As a result, an additional Dalek casing was constructed in-house by the BBC Visual Effects Department; this was much narrower than its Shawcraft-built counterparts.

Location filming principally took place at Grim's Dyke, a mansion house at Harrow Weald in London that was currently being used as a rehabilitation centre. Built in 1872, Grim's Dyke had once been the home of Sir William Gilbert, one half of opera's famed Gilbert and Sullivan partnership. For The Evil Of The Daleks, it posed as Maxtible's estate. Work on April 20th began on the grounds of Grim's Dyke, before cast and crew moved indoors for the rest of the shoot. Recording continued there on the 24th and 25th; the final day at Grim's Dyke involved a rare instance of night filming for the fight sequence between Jamie and Kemel. In between, on April 21st, the material at Gatwick Airport was filmed at hangars on Kendal Avenue in Ealing, London, while the scene at the railway arches was captured at Warehouse Lane in Shepherd's Bush, London.

Filming at the BBC Television Film Studios in Ealing, London then took place from April 26th to 28th. The first two days were largely devoted to model shots, while the last saw the completion of the Episode Four scenes involving the Doctor and a Dalek watching Jamie's trials; this would provide Patrick Troughton with the opportunity to enjoy a week's holiday during studio recording. Additional filming at Ealing then took place on May 16th and 17th to enact the sprawling Dalek civil war. Given the enormity of the workload, Martinus was deputised on these dates by production assistant Timothy Combe, who would himself become a Doctor Who director in the early Seventies. Anticipating the possibility that the BBC might one day wish to bring back the Daleks, Head of Drama Sydney Newman asked for the inclusion of some indication that these events might not represent their utter annihilation. Combe obliged by showing the Dalek Emperor clinging to life in its final scene.

Around the end of April, Gerry Davis stepped down as Doctor Who's story editor. His assistant, Peter Bryant, had been promoted to associate producer for The Faceless Ones, since it was now expected that he would eventually take over from Innes Lloyd. Although the original plan had been for Bryant to serve in this capacity on The Evil Of The Daleks as well, it was now agreed that he would officially succeed Davis as story editor, beginning with Episode Four. Victor Pemberton, who had appeared in a small role during The Moonbase a few months earlier, was named the new assistant story editor.

During the '80s, Patrick Troughton proposed remaking The Evil Of The Daleks as a feature film

Recording for The Evil Of The Daleks began on May 13th at Lime Grove Studio D in Shepherd's Bush. As usual, episodes were taped on consecutive Saturdays. May 20th marked Deborah Watling's debut in the studio; she was joined by Jo Rowbottom, who had unsuccessfully auditioned to play Victoria, but was instead cast as Mollie Dawson. Troughton was on vacation when Episode Four was made on June 3rd; coincidentally, Watling was also absent on this day, as her lone scene had been pre-filmed. Production wrapped up on June 24th but, although The Evil Of The Daleks was intended to conclude Doctor Who's fourth broadcast season, the recording block would continue with The Tomb Of The Cybermen for the start of Season Five. Troughton had greatly enjoyed The Evil Of The Daleks; during the Eighties, he even proposed remaking it as a feature film.

The broadcast of Episode One on May 20th was slightly delayed, to 6.00pm, to accommodate the FA Cup Final between Chelsea and Tottenham Hotspur. With Episode Three on June 3rd, Doctor Who's regular timeslot was moved back by five minutes, to 5.45pm. Although The Dick Van Dyke Show still normally followed it in the BBC's schedules, the comedy was preempted by cricket coverage on two occasions during the broadcast of The Evil Of The Daleks: first after Episode Four on June 10th, and again after Episode Six on the 24th.

On July 1st, Episode Seven was pushed back to 6.25pm by the early rounds of the Wimbledon tennis tournament, and it was followed by additional highlights from the All England Lawn Tennis Club. The broadcast of the season finale meant that the Doctor Who team had survived the perilous production schedule under which they had laboured since The Underwater Menace in January, with each episode going before the studio cameras just one week ahead of transmission. Despite the complete absence of a margin for error, the skill and tenacity of the cast and crew had helped ensure that Doctor Who made it to air every Saturday.

• Doctor Who Magazine #200, 9th June 1993, “Archive: The Evil Of The Daleks” by Andrew Pixley, Marvel Comics UK Ltd.
• Doctor Who Magazine Special Edition #4, 4th June 2003, “Good Vibrations” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #10, 2017, “Story 36: The Evil Of The Daleks”, edited by Mark Wright, Hachette Partworks Ltd.
• Doctor Who: The Handbook: The Second Doctor by David J Howe, Mark Stammers and Stephen James Walker (1997), Virgin Publishing.
• Doctor Who: The Sixties by David J Howe, Mark Stammers and Stephen James Walker (1992), Virgin Publishing.