In the twenty-second century, the TARDIS lands on a tiny Earth island during a solar storm. A factory there pumps out acid so corrosive that the work is performed by artificial humans, created from programmable matter called the Flesh. These Gangers take the form of the employees who control their duplicates remotely. They share all the memories and personalities of the real humans, but are supposed to lose their sentience once the connection is broken. When a power surge during the solar storm causes the Gangers to stabilise, however, the Doctor must avert a war between the humans and their Flesh counterparts.

After writing Fear Her for Doctor Who's twenty-eighth season, Matthew Graham continued to discuss story ideas with the production team. At one point, he was to write either the tenth or eleventh episode of Season Twenty-Nine, and he later developed an unused storyline for Season Thirty-One. On both occasions, however, he was prevented from returning to the show by his commitments to the spin-offs from his successful police drama Life On Mars -- namely its sequel, Ashes To Ashes, and its American remake. Finally, around February 2010, executive producer Steven Moffat convinced Graham to become involved with Season Thirty-Two.

It was initially planned that Graham would write a single-episode story, but Moffat persuaded him to tackle a two-part adventure, citing his love of Doctor Who cliffhangers. As a starting point, Moffat suggested fusing elements from two sources: the remotely-controlled synthetic bodies at the heart of the 2009 blockbuster Avatar, and the shapeshifting monster in the 1982 thriller The Thing. This led to the notion of the Flesh, and a story pitting artificially-created duplicates against their human originals. While Moffat anticipated the story taking place in a factory, Graham was keen to juxtapose the industrial flavour of the narrative with the solemnity of a monastery, recalling the 1986 Sean Connery mystery The Name Of The Rose. The ultimate setting blended each of their visions. Originally, the facility would have housed a much larger complement of both staff and Gangers, but these numbers were cut back both for budgetary reasons and to accentuate the atmosphere of claustrophobia and paranoia.

Steven Moffat indicated that the Doctor should be proactively investigating the Flesh

As production neared, the two scripts came to be known as The Rebel Flesh and “Gangers”. Moffat was also in the process of formulating his overall plans for Season Thirty-Two, which would be broadcast in two halves split across the summer months. As episode six, “Gangers” would be the penultimate installment before the hiatus. Consequently, Moffat asked Graham to lead into the mid-season finale, A Good Man Goes To War, by revealing that Amy was herself a Ganger, whom the “Eye Patch Lady” glimpsed in earlier episodes had substituted for the kidnapped -- and pregnant -- original. This replaced an ending in which Amy had a vision of the “Eye Patch Lady” while the Doctor and Rory headed back to the TARDIS. Moffat also indicated that the Doctor should be proactively investigating the Flesh, rather than happening upon the St John's monastery by chance.

Graham's story was made as the third recording block for Season Thirty-Two. It was directed by Julian Simpson, a writer-director whose wife, Jana Carpenter, had played De Maggio in 2005's Dalek. To prepare for the technically-complex production, he shadowed Toby Haynes for several days in mid-October during Block Two, which consisted of the season premiere, The Impossible Astronaut / Day Of The Moon. Graham, Moffat and Simpson all agreed that a point of reference for the story should be Mary Shelley's 1818 novel Frankenstein; or, The Modern Prometheus and its various film adaptations, which likewise featured an electrical storm giving life to a synthetic person.

Simpson's first order of business was a day on the TARDIS set at Doctor Who's usual studio home in Upper Boat; it took place on November 23rd, the programme's forty-seventh anniversary. November 24th to 26th were spent at the first of five locations to represent St John's. This was Cardiff Castle, originally constructed in the late eleventh century, where Simpson recorded scenes in various passageways, as well as the thermostatic chamber. Work began at Caerphilly Castle in Caerphilly on November 27th, initially for material in the evac tower. Unfortunately, an early winter storm bore down on the region, and Simpson injured his ankle after slipping on ice outside his flat, limiting his mobility for the remainder of the shoot.

After a day off on Sunday the 28th, the following week -- from November 29th to December 3rd -- was spent back at Caerphilly Castle. In addition to more sequences in the evac tower, the location also offered areas suitable for the monastery roof, the site where the TARDIS materialised, the operating alcoves, the storeroom, the washroom, the monitoring station, and further corridors. Recording at Caerphilly Castle wrapped up after the weekend, on December 6th. The third St John's location was Neath Abbey in Neath, where recording had originally been planned for early January. Instead, it was rescheduled for December 7th to 11th, and focussed on material in the chapel, as well as more hallways.

Sunday the 12th was another rest day for the cast and crew, after which Simpson's team moved to Chepstow Castle in Chepstow -- another eleventh-century edifice -- on December 13th. It was used for scenes in the locker room and the secure room, plus a shot of the flare. The final location before the Christmas break was St Donat's Castle in Llantwit Major, part of Atlantic College. It principally offered a space which could serve as the dining hall, although material in the courtyard and on the beach was also recorded there. Adam's half of the holo-call was taped against a green screen, while some pick-up shots were completed as well. Filming at St Donat's was meant to span December 14th to 17th, but wrapped up a day early due to another snowstorm.

To compensate for the early start to their Christmas break, cast and crew returned from holiday a day early, resuming work at St Donat's on January 3rd, 2011 and wrapping up there on the 4th. The 5th saw cameras again rolling at Cardiff Castle, before Simpson's team retreated from the wintry cold to Upper Boat. January 6th was focussed on material in the crypt. These sequences were completed the following day, after which the remaining Upper Boat schedule for the 7th and 8th consisted of TARDIS scenes, green screen shots and various inserts. Part of the 8th also saw recording at the Senedd in Cardiff, which represented the Morpeth-Jetsan offices. The concluding scene of Amy awakening in the birthing room on Demons Run was then recorded at Fillcare in Pontyclun on January 27th, during the making of A Good Man Goes To War. Subsequently, pick-up shots were completed at Upper Boat on February 14th and April 18th.

The Ganger Doctor's death was to be accompanied by a montage of happy memories which spanned the history of Doctor Who

A considerable amount of material was cut from the two episodes in post-production. Much of this involved character elements, such as Jennifer having perfect recall -- explaining why her Ganger was able to overcome the memory suppression protocols -- and the Doctor and his Ganger reminiscing about past companions and adventures. The death of the Ganger Doctor was to be accompanied by a montage of happy memories which spanned the entire history of Doctor Who. The arrival of the TARDIS at St John's was originally more involved, and included the Doctor revealing the existence of a “dear little hatch” in the bottom of the police box. Also dropped was the presence of a Chef computer in the dining room, which chatted with the humans in a Yorkshire accent. At a late stage, “Gangers” was retitled The Almost People.

Doctor Who continued to drift later in the BBC One schedule during the broadcast of The Rebel Flesh / The Almost People on May 21st and 28th, with both episodes airing at 6.45pm. In between, on May 26th, it was announced that executive producer Piers Wenger would be leaving the BBC in September; his last involvement with Doctor Who would prove to be the 2011 Christmas special, The Doctor, The Widow And The Wardrobe. Wenger had already stepped down from his post as Head of Drama for BBC Wales in March, but had remained with the Corporation to focus on creative development. He would now become the senior commissioning executive for Film4.

• Doctor Who Magazine Special Edition #30, 21st March 2012, “The Rebel Flesh / The Almost People” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #67, 2016, “Story 217: The Rebel Flesh / The Almost People”, edited by Mark Wright, Hachette Partworks Ltd.