The Monks have protected and guided the people of Earth since the beginning of time. Or have they been the planet's conquerors and dictators for just the last six months? Bill finds herself one of a small number of “memory criminals” who remember events differently, and she becomes determined to find the only man who can restore history to the way it was meant to be. But the Doctor is now a spokesperson for the Monks, reinforcing humanity's new narrative. With Nardole's help, Bill must undertake a desperate gambit to discover the truth.

As Peter Harness developed The Pyramid At The End Of The World during the early months of 2016, Doctor Who executive producer Steven Moffat saw considerable potential in its villainous Monks. He decided that the middle part of Season Thirty-Six should consist of three adventures, linked by the involvement of the Monks. His own Extremis would be the year's sixth episode and introduce the threat, thereby setting up Harness' script. For episode eight, Moffat envisaged a narrative set on a dystopian Earth where the Monks had apparently won, and the Doctor seemed to be their willing collaborator. As part of the resolution to the scenario, the Doctor's Time Lord arch-enemy, Missy, would be freed from the vault in which she had been held captive throughout the year. This would then propel the exploration of her possible redemption, which would feature prominently in the latter stages of the season.

To write episode eight, Moffat turned to Toby Whithouse, who had last contributed Season Thirty-Five's Under The Lake / Before The Flood. A key influence was George Orwell's 1949 novel Nineteen Eight-Four, which examined the manipulation of facts in a totalitarian society. The notion of disinformation had taken on a new relevance in recent months, sparked by the acrimonious 2016 presidential campaign in the United States. Republican candidate Donald Trump had been routinely dismissive of legitimate facts with which he was unhappy -- what he would later take to calling “fake news” -- while promoting his own fictions as authentic. As such, a key element of the script would be the Monks' dissemination of a bastardised version of Earth's history which served to reinforce their position of dominance over humanity.

At one stage, the Monks began to erase Bill's memories of her mother from her mind

Whithouse completed his first draft in mid-September, and the story was called The Lie Of The Land by the start of 2017. At one stage, Bill's memories of her mother weren't enough to free humanity from the Monks' brainwashing, and the aliens began to erase them from Bill's mind. It was then Bill's grief at the thought of forgetting her mother which shattered the Monks' influence. The interior of the vault was initially conceived as a spartan cell, rather than a grand hall with Missy's cage in the centre.

The Lie Of The Land was paired with episode nine, Empress Of Mars, as the sixth recording block of the Season Thirty-Six production schedule. The director was Wayne Yip; although he was a newcomer to Doctor Who, he had recently made Detained and The Metaphysical Engine, or What Quill Did for the 2016 spin-off series Class.

The first day of recording for The Lie Of The Land -- January 16th -- was spent in the Grangetown area of Cardiff. The home stormed by the Memory Police was on Avondale Crescent, their abortive attempt to arrest a citizen at the story's climax took place on Bradford Street, and Grangetown Primary School was the setting for flashbacks of the teenaged Bill. The Season Thirty-Six trailer was taped on the 17th, so Yip's next day of work was January 18th. Material in the Doctor's train carriage hideout was filmed at the Barry Tourist Railway in Barry; footage of a Monk executing prisoners was also captured there. The rest of the day was spent back in Cardiff, at Doctor Who's usual production home of Roath Lock Studios. A start was made on sequences in the Monks' Cathedral, and this work continued through to the 20th.

After the weekend, January 23rd to 25th focussed on the Doctor's rescue from the prison ship by Bill and Nardole. Daylight hours were spent at Roath Lock, where sets had been erected to represent the vessel's corridors and the Doctor's cell. After dark on all three days, however, cast and crew shifted to the nearby Cardiff Sailing Centre for scenes on the prison ship's deck, aboard the supply boat, in the harbour master's office, and on the dock. On January 26th, exterior shots of St Luke's University were staged at Cardiff University. The latter part of the day again saw cameras rolling at Roath Lock, first for the remaining material in the Doctor's cell, and then for inserts at the door to the Cathedral. The 27th took Yip's team to Cory's Building in Cardiff, from which the Doctor and his party launched their attack on the Cathedral.

Recording for The Lie Of The Land became more sporadic following the weekend, as Yip began to turn his attention to Empress Of Mars. On January 30th, Cory's Building was the venue for shots of Richard taking up a rooftop sniper position across from the Cathedral. There were intended to be two Monks blocking the entrance, both of whom Richard cut down. However, this sequence was dropped in editing and Nardole's dialogue was revised to indicate that the doors were unguarded. Back at Roath Lock, the usual set built for the Welsh-language soap opera Pobol y Cwm served as Bill's flat; several pick-up shots were also taped.

On January 30th, Peter Capaldi revealed that he would not be returning for Season 37

Meanwhile, on that day's edition of Jo Whiley's radio programme, Peter Capaldi revealed that he would not be returning for Doctor Who's thirty-seventh season. Although incoming executive producer Chris Chibnall had invited Capaldi to remain on the show, the actor had concluded that he was comfortable wrapping up his tenure after three seasons. This was effectively the same length of time for which Capaldi's two immediate predecessors, Matt Smith and David Tennant, had starred in Doctor Who.

The next day of work on The Lie Of The Land was February 3rd. The Doctor's opening speech was filmed on the prison cell set at Roath Lock, together with a number of pick-up shots. On the 5th, Cardiff's Mount Stuart Square was the venue for various scenes including the raid on the Cathedral, the crowd swarming a Monk, and Bill walking home. The nearby premises of Octavo Book Publishing and Marketing Services was then mocked up as the exterior of Magpie Electricals, while a drone captured aerial footage. It was back to Mount Stuart Square on February 12th, for shots of a Monk atop its plinth. The same day, more inserts were taped at Roath Lock, as was a specially-written scene featuring actors Amanda Mealing and Tony Marshall as their characters in the medical drama Casualty. Intended to appear on the family's television prior to the mother's apprehension by the Memory Police -- but ultimately dropped in post-production -- it saw physician Connie Beauchamp and receptionist Noel Garcia discuss a patient who was saved from her exploding automobile by a Monk.

More drone footage was captured on February 13th, this time at the Cardiff Sailing Centre and depicting the supply boat at sea. The Doctor and Bill gained access to the vault during recording at Roath Lock on the 20th. Material within the vault was filmed at the Coal Exchange in Cardiff on February 21st and 22nd. Part of the latter day was also spent back at Roath Lock, with a green screen used to capture a shot of the supply boat approaching the harbour. An insert of the Doctor's hand on the vault door was taped in the studio on the 23rd. Finally, young Bill on the playground was recorded on February 24th, near the Norwegian Church in Cardiff Bay.

Amongst the sequences omitted in editing was some of Missy's explanation about the Monks. Her previous encounter with them occurred on the planet Riga-Priam during her “goatee beard phase” -- a reference to the incarnations of the Master played by Roger Delgado and Anthony Ainley. The Monks' requirement that only a person who held power could consent to their dominion, as seen in The Pyramid At The End Of The World, stemmed from their assumption that such an individual would be well-protected, making it more likely that the psychic link would be passed down through generations. At the end of the adventure, the Doctor and Missy fondly recalled the sword fight between Delgado's original Master and Jon Pertwee's Third Doctor in 1972's The Sea Devils.

The Lie Of The Land was scheduled for 7.35pm, fifteen minutes earlier than the football-delayed The Pyramid At The End Of The World. Its lead-in was the 1981 adventure film Raiders Of The Lost Ark, while Casualty once again followed Doctor Who, as had been the case earlier in the season. Unfortunately, The Lie Of The Land was broadcast opposite the final of the popular Britain's Got Talent reality competition. As a result, its seven-day audience figure fell under five million viewers, making it the first episode since Episode Two of 1989's Survival to do so.

• Doctor Who: The Complete History #88, 2019, “Story 272: The Lie Of The Land”, edited by Mark Wright, Hachette Partworks Ltd.