The rebellious warrior Leela is cast out of the Sevateem tribe after she doubts the existence of their god, Xoanon. Left to fend for herself in a phantom-plagued jungle, she meets the Doctor -- who is baffled when she recognises him as the mythical Evil One. The Doctor manages to earn Leela's trust by warding off the phantoms, and she brings him to a giant carving of his own face in a mountainside. Returning to the Sevateem village, the Doctor finds relics of advanced technology, and discovers that the voice of Xoanon is his own. As the mystery unravels, the Doctor realises that a past mistake is finally catching up to him...

In early 1975, the Doctor Who production office received a brief, unsolicited submission entitled “The Silent Scream” from a part-time scriptwriter named Chris Boucher. Although it was quickly deemed unusable, its quality was such that Doctor Who producer Philip Hinchcliffe and script editor Robert Holmes decided to work with Boucher on more suitable concepts. They suggested that he develop a story involving a society controlled by a malfunctioning computer. Hinchcliffe also wanted a scenario in which the Doctor had to contend with the ramifications of his past actions. Inspired by Harry Harrison's 1969 novel Captive Universe, Boucher developed “The Dreamers Of Phados”, an adventure for the Fourth Doctor and Sarah Jane Smith which took place on a giant colony ship.

Hinchcliffe disliked the spaceship setting, and proposed the idea of the Doctor landing on a planet to find his own face was carved into a mountainside. The producer was thinking in terms of Mount Rushmore in South Dakota, upon which four American presidents were sculpted in the 1930s. Boucher's revised storyline was commissioned on August 19th as “Prime Directive”. It became “The Mentor Conspiracy” during its development, and amongst the characters were the tribal leader Andor and the outcast Leela. The latter was envisaged a mix of Palestinian terrorist Leila Khaled -- whose name he also borrowed -- and Diana Rigg's dynamic Emma Peel from The Avengers. However, when Boucher submitted “The Mentor Conspiracy” on October 30th, Holmes found that it still needed work, and rejected it.

The name Xoanon came from a Greek term for a venerated wood carving

Boucher redeveloped the storyline as “The Tower Of Imelo”, introducing the rival tribes of the Sevateem and the Tesh. Aldous Huxley's 1932 classic Brave New World influenced Boucher's ideas about how the tribal religion had evolved, while the name Xoanon came from a Greek term for a venerated wood carving. On January 27th, 1976, full scripts for the serial were requested, now using the title “The Day God Went Mad”.

By this stage, it was known that Elisabeth Sladen would be leaving Doctor Who early in Season Fourteen, and Hinchcliffe and Holmes had decided to delay introducing her replacement. Instead, Boucher was told to develop a character who could temporarily fulfil the companion's role for the duration of “The Day God Went Mad”. To this end, he began expanding the role of a male Sevateem warrior named Loke. However, Holmes felt that a female character would be more appropriate and so Boucher reintroduced Leela for this purpose; Loke was renamed Tomas, and his role was diminished.

Holmes' tentative plan for the Doctor's next companion was to introduce a Victorian street urchin character, likely in the season finale. Although not opposed to this idea, Hinchcliffe preferred a strong, more relatable female protagonist. While reading a draft of Boucher's Episode Two script in mid-March, the producer hit upon a potential compromise. He appreciated Leela's self-assurance, while her primitive and childlike nature were akin to Holmes' concept. The script editor agreed, and felt that Leela might offer a similar appeal as Raquel Welch's cavegirl heroine Loana in the 1966 movie One Million Years BC.

In mid-June, it was decided that Leela should be retained for at least one more story. Since only Boucher was familiar with the character, he was commissioned to write a second adventure called The Robots Of Death, which would follow “The Day God Went Mad” into production. As a means of further distinguishing the new companion, Holmes suggested that Leela should possess some sort of supernatural powers, which he thought might be inherited from a witch-priestess grandmother. Boucher was not fond of this idea, and instead opted to grant her a sort of sixth sense for danger.

The director assigned to “The Day God Went Mad” was Pennant Roberts, who was working on his first Doctor Who serial. One of his key responsibilities was the search for an actress to play Leela. Mooted to play the new companion in the character's street urchin incarnation had been Twiggy, a former phenomenon in the modelling world who had earned two 1972 Golden Globe Awards for The Boy Friend. In the event, Roberts auditioned sixty actresses to play Leela and selected Louise Jameson, whom he had previously considered for a part in the post-apocalyptic drama Survivors. By the time Jameson was issued her contract on August 27th, it had been decided that Leela would remain for the season's final serial as well; as such, she was booked for a total of fourteen episodes. Meanwhile, amongst the fifty-nine unsuccessful applicants was Pamela Salem, who was instead offered voicework on “The Day God Went Mad”, as well as the prominent role of Toos in The Robots Of Death.

For her portrayal of Leela, Louise Jameson took inspiration from a little girl, as well as her own dog, Bosie

Jameson worked closely with Roberts to shape her portrayal of Leela. She took inspiration from both a little girl who lived in her building, as well as her own dog, Bosie. Leela's physical appearance evolved during the weeks before production began. Jameson's contract included a provision that she wear brown contact lenses to mask her blue eyes, and it was also decided that she should wear make-up to darken her skin. Initially, this was a very deep brown colour, as seen in several publicity photos; ultimately, however, a more muted shade was chosen. Sadly, Jameson was greeted with a frosty reception from Tom Baker. He objected to being saddled with a new companion, and especially one who wore a skin-baring costume. He also felt that Leela's violent tendencies were inappropriate for Doctor Who. Nonetheless, Baker grudgingly accepted Jameson when he was told that Leela was only due to appear in a trio of stories.

With both the preceding serial, The Deadly Assassin, and the season finale expected to be expensive productions, “The Day God Went Mad” was designed to be made on a limited budget. There would be no work on location and, originally, no filming of any sort. Eventually, however, Hinchcliffe managed to secure several days at the BBC Television Film Studios in Ealing, London. This was scheduled to run from September 20th to 24th, and then conclude on the 27th after a break for the weekend. The principal focus was material in the jungle, although sequences in the Horda pit were also recorded on the 23rd and part of the 24th. Unfortunately, the pace of filming was slower than anticipated, necessitating an additional day on September 28th.

Around the start of October, it was decided to rename the serial The Face Of Evil. Boucher was happy with this change, as he felt that “The Day God Went Mad” was an unnecessarily pretentious title. The remainder of the serial was completed at BBC Television Centre Studio 3 in White City, London, starting on October 11th and 12th. The first day saw most of Episode One recorded, along with those scenes in the jungle for Episodes Two and Four which had not already been captured at Ealing. On the second day, Roberts taped most of the remaining Episode Two material and the sole sequence in Neeva's sanctum for Episode Three, along with effects work.

Recording wrapped up with a three-day block from October 24th to 26th. The 24th was largely devoted to scenes outside and within the massive sculpture of the Evil One, although time was also spent on Episode Three material in the control room and the particle analyser. For the penultimate installment's cliffhanger, Xoanon's line “Who am I?” was recorded by twelve year-old Anthony Frieze, a pupil at the school where Roberts' wife, Betsan Jones, worked as a teacher. Episode Three was completed the next day, before Roberts moved on to a trio of scenes from the serial's final part. The rest of Episode Four was then taped on the 26th.

Louise Jameson's photocall had to be hastily arranged after the news broke the night before

On the same day that production wrapped on The Face Of Evil, a photocall was held to introduce Louise Jameson as the new companion. This event had to be hastily arranged after the Evening Standard broke the news of her casting the night before. Originally, Leela's debut was intended to air on November 27th -- the week after The Deadly Assassin concluded -- with The Face Of Evil then completing its run before a one-week Christmas break. However, with the season finale having been plagued with script problems, it was decided around September that a longer mid-run break would be beneficial.

As such, Doctor Who took five weeks off after The Deadly Assassin. In addition to festive programming, its timeslot was filled in the interim by edited compilations of the Season Thirteen serials Pyramids Of Mars and The Brain Of Morbius. This meant that Leela's on-screen debut was delayed until New Year's Day 1977. In response to complaints about the content of several recent serials, Doctor Who was now pushed back to 6.20pm (or 6.30pm in the case of The Face Of Evil Episode Two). This meant that it aired after Jim'll Fix It and before Saturday Night At The Movies.

• Doctor Who Magazine #229, 30th August 1995, “Archive: The Face Of Evil” by Andrew Pixley, Marvel Comics UK Ltd.
• Doctor Who Magazine Special Edition #8, 1st September 2004, “Take It To The Limit” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #26, 2015, “Story 89: The Face Of Evil”, edited by John Ainsworth, Hachette Partworks Ltd.
• Doctor Who: The Handbook: The Fourth Doctor by David J Howe, Mark Stammers and Stephen James Walker (1992), Virgin Publishing.
• Doctor Who: The Seventies by David J Howe, Mark Stammers and Stephen James Walker (1994), Virgin Publishing.
• In·Vision #19, October 1989, “Production” edited by Justin Richards and Peter Anghelides, Cybermark Services.