The Time Lords send the Second Doctor and Jamie to Space Station Camera, to put an end to dangerous temporal experiments. The Doctor appeals to his old friend, Dastari, but is betrayed: Dastari has genetically augmented a savage Androgum named Chessene, who has forged an alliance with the Sontarans. The captive Doctor is taken to Seville, where Dastari plans an operation to isolate the genetic code which permits time travel. Suddenly gripped by a memory of being executed in his second incarnation, the Sixth Doctor rescues Jamie and travels with Peri to Seville -- where both his past and his future are at stake.

For many years, Doctor Who had failed to make much of an impact in North America. That began to change during the mid-Seventies, when the transmission of Tom Baker episodes on Public Broadcast Service stations began to ignite a cult following in the United States and Canada. John Nathan-Turner became aware of this burgeoning fandom when he was still Doctor Who's production unit manager. Upon taking over as the programme's producer in late 1979, he made it a priority to investigate the possibility of location filming in the USA. Despite the enormous costs involved, he was optimistic that the BBC's North American distributor, Lionheart, would be willing to invest in such a project.

In particular, a trip to Mardi Gras in March 1981 inspired Nathan-Turner's interest in a story set in New Orleans, Louisiana. Later that year, a narrative entitled “Way Down Yonder” was briefly developed by Lesley Elizabeth Thomas, an American writer working in England. Around the same time, unsuccessful inquiries were made about shooting at the Walt Disney World theme park in central Florida. Instead, Doctor Who's first trip abroad under Nathan-Turner's aegis was to Amsterdam in the Netherlands, for 1982's Arc Of Infinity. The next year, Lanzarote, Spain played host to Planet Of Fire. However, Nathan-Turner had not abandoned his plan to take Doctor Who Stateside and, around the end of 1983, he and Lionheart reached a verbal agreement on the necessary funding.

Patrick Troughton had enjoyed making The Five Doctors, and was readily enticed back to Doctor Who

Meanwhile, after making the twentieth-anniversary special The Five Doctors in 1983, Nathan-Turner was keen to put together another story involving one or more of the Doctor's past incarnations. Most notably, he hoped to once again entice the Second Doctor, Patrick Troughton, back to Doctor Who, and he offered Troughton the opportunity at the Spirit of Light convention in Chicago that November. Troughton had very much enjoyed the experience of making The Five Doctors, and he readily accepted Nathan-Turner's invitation.

Both Troughton and Nathan-Turner also hoped that Frazer Hines might return to play the Second Doctor's companion, Jamie McCrimmon. Hines had appeared on Doctor Who for virtually all of Troughton's tenure in the late Sixties, and the two actors shared a tremendous camaraderie. Unfortunately, commitments to the soap opera Emmerdale Farm had forced Hines to limit his involvement in The Five Doctors to just a brief cameo. However, Hines was planning to take an extended hiatus from Emmerdale Farm in the second half of 1984, opening a window to fully participate in a new Doctor Who serial.

It was decided that the milestone nature of the Sixth Doctor's encounter with his earlier self would pair well with the unprecedented transatlantic filming. To write such a landmark adventure, script editor Eric Saward encouraged Nathan-Turner to approach Robert Holmes, who had just completed the Fifth Doctor's 1984 swansong, The Caves Of Androzani. In addition to the New Orleans setting and the presence of the Second Doctor and Jamie, Nathan-Turner also asked Holmes to bring back the Sontarans, the militaristic clone race which Holmes had created for 1973's The Time Warrior. The aliens had not appeared in Doctor Who since The Invasion Of Time in 1978, but Andrew Smith's “The First Sontarans” had entered development at the start of 1984. Smith's storyline was promptly shelved so that the Sontarans could be available to Holmes.

Holmes agreed to try his hand at the proposed story, despite his discomfort with the shopping list of ingredients he was being asked to incorporate. Although he disliked reusing old monsters, Holmes felt that the Sontarans had been poorly served by other writers in their appearances since The Time Warrior -- in 1975's The Sontaran Experiment as well as The Invasion Of Time -- and he saw this as an opportunity to reassert his original vision for the monsters.

Holmes considered the New Orleans locale to be a handicap, offering little benefit to the adventure. However, he was determined to make every possible use of the setting, and so he decided to pair the Sontarans with a new race of aliens influenced by some essential facet of New Orleans culture. He quickly rejected the notion of making them jazz connoisseurs, and instead decided to draw upon the Big Easy's reputation as a centre of culinary art to create the Kraalons, a race of alien gourmands.

The concept of isolating the genetic ability to travel in time was recycled from Robert Holmes' abandoned version of The Five Doctors

Encouraged by this idea, Holmes composed a storyline entitled “The Kraalon Inheritance”. It ran to three forty-five-minute episodes, the longest story attempted under Nathan-Turner's producership; this was dictated by the need to make maximum use of the overseas locale. The concept of isolating the Doctor's genetic ability to travel in time was recycled from “The Six Doctors”, Holmes' abandoned version of The Five Doctors. The script for Episode One was commissioned on February 13th, 1984, with the remaining installments following on March 9th.

As work on “The Kraalon Inheritance” progressed, trouble was brewing. It became clear that Lionheart would not be able to cover the cost of the expedition after all and, on February 15th, Nathan-Turner wrote to BBC Enterprises -- the commercial wing of the BBC -- in the hope that they would be interested in making up the shortfall. Preparations continued unimpeded, however, with Troughton and Hines both contracted on February 29th. Holmes' serial had now been scheduled as the third adventure to be made as part of Season Twenty-Two, although it would ultimately change places in the broadcast schedule with The Mark Of The Rani, becoming the fourth transmitted adventure.

The final nail in the New Orleans coffin was driven home on April 16th, when the office of Graeme MacDonald, the Head of Drama, informed the Doctor Who production team that no money would be made available for filming in the United States. Working quickly, Nathan-Turner suggested Venice, Italy as an alternative location, but it was soon determined that the crush of tourists, plus the higher associated costs, would be prohibitive. Production associate Sue Anstruther then proposed filming in Seville, Spain, where she had holidayed a few years earlier. It was found that this was a feasible venue, as long as the cast and crew voluntarily accepted a cut in the normal rates for meals and lodgings.

In early May, Holmes reluctantly agreed to rewrite his scripts to account for the new setting. He was bitterly disappointed that much of the humour he had developed -- often drawing upon the linguistic differences between British and American English -- had to be discarded. Fortunately, in many instances, the process of revision was made easier because Seville offered an obvious alternative to Holmes' planned locations: New Orleans' French Quarter became Seville's Arab Quarter, a plantation house became the hacienda, the banks of the Mississippi became an olive grove, and so forth.

Around this time, the Kraalons became known as the Androgums -- an anagram of “gourmands” -- and the story was duly renamed “The Androgum Inheritance”. (The title “The Kraglon Inheritance” also appears on some paperwork, although it is likely that this was merely a typographical error.) It seems that several other titles -- including “Creation”, “Parallax”, “The Seventh Augmentation” and “The Seventh Amendment” -- were then briefly considered, before the production team opted for The Two Doctors by the start of June. The name Dastari was also anagrammatical, having been formed by rearranging the letters in “a TARDIS”.

Peter Moffatt chose to deviate from earlier Sontaran stories by casting tall actors as Stike and Varl

The director assigned to the serial was Peter Moffatt, who had last handled the Sixth Doctor's introductory story, The Twin Dilemma, at the end of the previous season. Playing Chessene would be Jacqueline Pearce, who had risen to fame several years earlier as Servalan, the villainess of the BBC's more adult-oriented science-fiction drama, Blake's 7. Moffatt chose to deviate from earlier Sontaran stories by casting tall actors -- Clinton Greyn and Tim Raynham -- as Stike and Varl. The Sontarans had formerly been an explicitly short-statured race. Moffatt originally hoped to spend twelve days in Seville, followed by eight studio days back in London (one two-day block and two three-day sessions). These plans were eventually trimmed to eight days on location, followed by six days (three two-day blocks) in the studio.

Cast and crew departed England for Spain on August 7th. Problems plagued the trip right from the start, when the case containing all of the wigs and Androgum eyebrows went missing en route. Make-up artist Catherine Davies was forced to hurriedly replace the hairpieces with materials purchased in Seville. Extreme heat -- often approaching 40 degrees Celsius -- and stomach ailments also hampered the shoot.

The principal location was a dilapidated hacienda called Dehera Boyar, near Gerena. Designed by Anibal González Álvarez-Ossorio, an influential Spanish architect of the early twentieth century, it was in the process of being purchased by Joanne Hearst Castro, granddaughter of American press baron William Randolph Heart. The scenes in and around the home of the Doña Arana, including those amidst the olive grove, were recorded at Dehera Boyar from August 9th to 12th. For the destruction of the Sontaran ship on August 10th, the Visual Effects team was forbidden to import pyrotechnics. They originally tried to source materials from Madrid, but it soon became clear that the shipment would not arrive in time. Instead, designer Steven Drewett decided to create the necessary effect using gunpowder obtained from a firearms store in Seville. The resulting explosion was so effective that it spooked an elderly woman living on the grounds of the hacienda, who had to be persuaded that it was not the work of Basque separatists. Happily, Moffatt made such good progress at Dehera Boyar that there was enough time to record two scenes originally intended for the studio.

Following a day off, August 14th and 15th were spent at various locations in the Santa Cruz district of Seville itself. Several members of the crew wound up on camera in these sequences, including Moffatt and costume designer Jan Wright, who could be seen sitting outside the Bar Hosteria del Laurel in Episode Three. The woman who threw a flower to Dastari was Spanish aristocrat Mercedes Carnegie, the wife of Donald Carnegie, Assistant at the British Consul. Both Carnegies had been of great help to production manager Gary Downie while scouting for locations.

By now, however, Nathan-Turner had been informed that there was a scratch on one of the film negatives which had been returned to the UK for processing. Some of the material recorded at Dehera Boyar, involving James Saxon (Oscar) and Carmen Gomez (Anita) in the olive grove, would have to be remounted. Unfortunately, Saxon and Gomez had already returned to England, and this meant that they would have to be despatched back to Spain at great cost to the production office. These sequences were re-recorded at Dehera Boyar on August 16th. The same day, the scene of the Sixth Doctor fishing for gumblejacks was recorded at the nearby Rio Guadiamar. Moffatt's team was disappointed to discover that the extreme heat and lack of rain had considerably reduced the water level in the days since the location had been reconnoitred. Finally, the Second Doctor and Shockeye hijacked a lorry on the road from Gerena to El Garrobo.

Strained by the heat and the frustration of the remount, tempers began to fray, leading Nathan-Turner to vow that Doctor Who would never go abroad again. Though he could not have known it at the time, these words would turn out to be prophetic: although plans were then being made for filming in Singapore for Season Twenty-Three, it would never take place, and The Two Doctors would indeed enjoy the last overseas location shoot for Doctor Who prior to its cancellation in 1989. To make matters worse, upon Nathan-Turner's return to London the next day, he was outraged to discover that the reported scratch was virtually imperceptible. The expensive remount had not been necessary after all.

For the Second Doctor's TARDIS, the current console was replaced by the version which had been retired in 1983

The first studio session for The Two Doctors took place on August 30th and 31st at BBC Television Centre Studio 1 in White City, London. This block was chiefly dedicated to scenes on Space Station Camera, including corridor sequences on the first day, and those in Dastari's office, the kitchen and the computer room on the second day. Also taped on both days was material in the TARDIS. The current TARDIS console appeared as usual on August 30th, after which it was replaced by the version which had been retired following The King's Demons in 1983. This allowed for the recording of the opening scene aboard the Second Doctor's TARDIS on August 31st. In post-production, the start of this footage was converted to monochrome -- before gradually transitioning to colour -- in order to more faithfully hearken back to the Troughton era.

The remaining studio days saw The Two Doctors move to TC6. The focus for the next block, on September 13th and 14th, was the hacienda cellar set, while material in the outbuilding and the underground passage was also completed on the second day. That evening found a third Doctor present in the studio, as Fifth Doctor Peter Davison dropped by for a visit while filming L-Driver.

Production concluded on September 27th and 28th. The first day began with material in Oscar's restaurant, before Moffatt concentrated on scenes in the space station infrastructure. Bryant badly bruised her shin on the set during one shot, prompting an early end to the evening. The remaining infrastructure footage was instead captured the following day, alongside sequences in the kitchen, bedroom, hallway and chapel of the hacienda. Unusually, Moffatt was able to complete all of his required shots during the afternoon, resulting in the cancellation of the planned evening recording.

The Two Doctors marked Peter Moffatt's sixth and final contribution to Doctor Who. It was also the last televised Doctor Who serial for both Troughton and Hines. Although Troughton gleefully expressed the desire to covertly return inside a monster costume, this never came to pass. He suffered a fatal heart attack on March 28th, 1987, while attending a Doctor Who convention in the United States.

• Doctor Who Magazine #195, 20th January 1993, “Archive: The Two Doctors” by Andrew Pixley, Marvel Comics UK Ltd.
• Doctor Who Magazine Special Edition #3, 22nd January 2003, “Everything Must Change” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #41, 2018, “Story 140: The Two Doctors”, edited by John Ainsworth, Hachette Partworks Ltd.
• Doctor Who: The Eighties by David J Howe, Mark Stammers and Stephen James Walker (1996), Virgin Publishing.
• Doctor Who: The Handbook: The Sixth Doctor by David J Howe, Mark Stammers and Stephen James Walker (1993), Virgin Publishing.
• In·Vision #82, February 1999, “Production” edited by Anthony Brown, Cybermark Services.