It is 1911, and the TARDIS lands in the home of sibling scientists Marcus and Laurence Scarman. Something has happened to Marcus during an archaeological dig in Egypt, and he has ordered the sinister Namin to bar Laurence from the house. Furthermore, Laurence has begun detecting strange radio signals from the surface of Mars. The Doctor discovers that Marcus has become the avatar of Sutekh, a powerful alien Osirian who has spent centuries imprisoned on Earth by his people as retribution for his terrible crimes. Now Sutekh is using Marcus to regain his freedom, heralding the end of the world.

Doctor Who script editor Robert Holmes was determined to find new writers for the programme's thirteenth season. In the spring of 1974, he approached Lewis Greifer, a former colleague at ATV. Aware that Greifer had an interest in Egyptian mythology, Holmes suggested that he develop a scenario which would combine science-fiction with the trappings of mummy horror films, such as Universal Pictures' 1932 movie The Mummy and the 1959 Hammer Films production of the same name. Greifer agreed and submitted a prospective storyline around the start of July.

Here, the Doctor and his companion (referred to as “Jane”) attended a conference on food reserves at the British Museum, along with Brigadier Lethbridge-Stewart of the United Nations Intelligence Taskforce (UNIT). It was suggested that the Brigadier might be killed off during the adventure. The Doctor's friend Professor Fawzi and his partner, Dr Robertson, were there to unveil their work on a new type of grain which could flourish on the surface of the Moon, thereby solving the world's hunger problems. However, the conference was soon attacked by the crocodile-like Egyptian god Sebek and his army of mummies. Sebek and his master, Seth, were aliens who came to Earth millennia ago intent on conquest, but were placed in suspended animation via a powerful artefact called the Eye, wielded by Horus, another of their kind. Having reawakened, Seth and Sebek now intended to replace Fawzi and Robertson's grain with a type which would result in the Moon's disintegration -- which, in turn, would have catastrophic effects on Earth. The Doctor managed to locate Seth's resting place beneath an Egyptian pyramid, and was assisted by Horus and another deity, Isis, in defeating Seth and destroying the probe which carried the grain in mid-flight.

Barry Letts thought that the Egyptian gods might originate from different planets, explaining their varying physical forms

Despite grave misgivings with regards to Greifer's understanding of Doctor Who's format, Holmes met with the author on July 4th and fleshed out ideas for what was now called “The Pyramids Of Mars”. He suggested that the would-be gods could actually be from Mars, having fled the planet after it was devastated by intergalactic war. Holmes disliked the notion of the special grain, and instead recommended that the Earth project involve the transformation of Mars' surface into a habitable environment. Seth would attempt to hijack the mission, his goal being to fire a rocket at the Great Pyramid of Mars where his jailers still slept in suspended animation. Holmes also encouraged Greifer to establish scientific explanations for some of the supernatural phenomena he described. Producer Barry Letts -- who was in the process of handing over to his successor, Philip Hinchcliffe -- thought that the Egyptian gods might actually originate from different planets outside our solar system, explaining why their physical forms vary greatly.

Holmes formally commissioned Greifer to write a storyline for Pyramids Of Mars (the title having lost its definite article) on July 8th. At this point, he was considering the possibility of making the search for the Eye of Horus -- which would disappear at the serial's climax -- a recurring theme in subsequent adventures. Holmes continued to have reservations about Pyramids Of Mars even after Greifer submitted his revised outline, but still contracted the writer to provide the four scripts on July 23rd. Greifer's story now involved a fortune hunter named Hennessey who, at Fawzi's behest, was pursuing ancient wild rice hidden in an Egyptian sarcophagus. The ancient rice was also the target of Shebek (as Sebek had been renamed).

Greifer delivered the script for Episode One on September 23rd. On October 7th, Holmes cautioned him that he was straying too far away from the mummy horror movie premise. Matters deteriorated from there. First, Greifer was taken badly ill and required surgery, delaying the completion of the final three installments. Then, Holmes discovered that the finished scripts were unsuitable for production, failing to tie up key plot points and lacking a suitable emphasis on the Doctor's involvement. In late November, Greifer left England for Tel Aviv University in Israel, where he had previously committed to a teaching position.

Finally, on March 7th, 1975, Holmes informed Greifer's agent that his client's scripts would be abandoned. With production looming, Holmes was forced to rewrite the adventure from scratch. He was assisted by Paddy Russell, who had been assigned to direct the story; Russell's last Doctor Who work had been on Invasion Of The Dinosaurs two years before. Jettisoning most of Greifer's concepts -- such as the modern-day setting, UNIT, and Shebek -- Holmes instead situated the action in 1911, better facilitating an homage to the mummy horror genre. Seth became the focal villain, with Holmes referring to the character as Set and then Sutekh, both alternative names for the deity in Egyptian mythology.

The visit to the devastated 1980 was intended to offset the presumption that threats encountered in historical stories didn't matter

Holmes also took the opportunity to include a scene in Episode Two which depicted how the events of 1911 could change Sarah Jane's “present”. He felt that this would help offset the general presumption by viewers that threats encountered in historical stories didn't matter, since modern-day Earth had been seen to endure in other Doctor Who serials. Hinchcliffe, meanwhile, suggested the inclusion of the logic puzzle in the concluding installment, drawing on Franz Kafka's 1926 novel The Castle. The character of Ernie Clements was intended to survive the story in Holmes' original version, but Russell elected to kill him off instead.

Pyramids Of Mars was scheduled to be the first serial of Doctor Who's thirteenth recording block. It was also envisaged as the first adventure to air as part of Season Thirteen, but these plans changed when the BBC decided to move up the new season by four months, to the autumn of 1975. With Terror Of The Zygons now being held over from the twelfth production block to begin Season Thirteen, consideration was given to pushing Pyramids Of Mars as far back as fourth in the running order. Ultimately, it was decided to swap it with Planet Of Evil, the next story to be made, to avoid beginning the season with two Earthbound serials.

Location filming for Pyramids Of Mars took place on the grounds of Stargroves, a manor house in East End, Hampshire which would pose as the exterior of the Priory and its environs. At the time, the property was owned by Mick Jagger, lead singer of the Rolling Stones, and was occupied by his parents. Work at Stargroves began on April 29th and continued until May 2nd, during which Elisabeth Sladen battled a case of the flu. Cast as the poacher, Ernie Clements, was George Tovey; his daughter, Roberta, had played Susan, granddaughter to Peter Cushing's Dr Who, in two Dalek feature films during the Sixties. On May 1st, Tom Baker was frustrated when Russell insisted that he don a Mummy costume for the sequence where the Doctor masqueraded as one of the servitor robots. Russell felt that the actor's body language would be distinctive, but Baker disliked appearing in footage where he would not be recognisable and, to make matters worse, suffered painful scrapes on the fibreglass frame.

The location shoot was followed by model filming, which was conducted from May 7th to 9th at the BBC Television Centre Puppet Theatre in White City, London. By this time, Lewis Greifer had requested the removal of his name from a serial which bore almost no resemblance to what he had written. Instead, Pyramids Of Mars would carry an on-screen credit to the pseudonymous “Stephen Harris”.

As had become typical on Doctor Who, studio recording for Pyramids Of Mars took place on Mondays and Tuesdays, with each two-day block separated by a fortnight. The first session was held in BBC Television Centre Studio 3 on May 19th and 20th. A new TARDIS console room set was introduced, replacing the version built in 1972 for The Three Doctors and which had not been seen since Death To The Daleks in 1974. On the Monday, Russell completed most of Episode One. This was followed by the majority of Episode Two on the Tuesday, together with the lone TARDIS scene for the concluding installment.

Two more days of model filming then took place on May 22nd and 23rd, again at the Puppet Theatre. The second studio block was scheduled for June 2nd and 3rd, this time in TC6. Episode Three was Russell's primary concern on the Monday, although she also completed the tomb material for the start of Episode One and the early scenes of Episode Four. This time, a stand-in was used when the Doctor disguised himself as a Mummy. The remainder of Episode Four was then recorded on the Tuesday, alongside the effects sequence of Marcus being ineffectually shot by Clements for Episode Two.

• Doctor Who Magazine #300, 7th February 2001, “Archive: Pyramids Of Mars” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who Magazine Special Edition #8, 1st September 2004, “Bohemian Rhapsody” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #24, 2016, “Story 82: Pyramids Of Mars”, edited by Mark Wright, 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 #9, October 1988, “Production” edited by Justin Richards and Peter Anghelides, Cybermark Services.