Hundreds of years in the future, the population of Britain has fled an Earth ravaged by solar flares, aboard the mammoth Starship UK. But the Doctor and Amy discover that something about the enormous vessel is very wrong. The ship moves even though its engines aren't working, whole sections are closed off under mysterious circumstances, and the sinister robotic Smilers punish the disobedient. The Doctor finds himself assisted by an enigmatic female vigilante, while Amy learns the truth at the heart of Starship UK... but it's a truth that she can't bear to remember.

After writing The Time Of Angels / Flesh And Stone, Doctor Who showrunner Steven Moffat next turned his attention to the second story of the season. In particular, he wanted this episode to give Amy the opportunity to save the day, preventing the Doctor from making an understandable but terrible mistake, and thereby establish herself firmly as a worthy occupant of the TARDIS. Moffat was also keen to emphasise the fairytale nature of Doctor Who throughout the season. This adventure would embody that philosophy most fully, landing the Doctor and Amy in the midst of a fantastical, vaguely distorted and slightly sinister version of the real world. The script ultimately gained the title The Beast Below.

Assigned to direct the story, alongside Victory Of The Daleks, was Andrew Gunn. Gunn had begun his career making a number of short films; he eventually moved into television, directing for series such as The Bill, Life On Mars, Primeval and Survivors. The pair of episodes would be made as the second production block of the season. Cast in the role of Liz 10 was Sophie Okonedo, who had risen to fame after appearing in the dramatic feature film Hotel Rwanda. However, this was not Okonedo's first brush with Doctor Who. In 2003, she had provided the voice of companion Alison Cheney in the animated webcast Scream Of The Shalka, opposite Richard E Grant as a putative Ninth Doctor. At the time, it was planned that Scream Of The Shalka would inaugurate the official continuation of Doctor Who -- a plan that was quickly scuppered some months later following the decision to the bring the programme back to television.

Gunn planned to concentrate on filming Victory Of The Daleks early in the production block, and so the first scene shot for The Beast Below was Winston Churchill's cameo appearance, recorded at the bunker of the Joint Resilience Unit in Swansea on August 24th, 2009. This was the only footage completed for The Beast Below until September 7th, when the material involving the Doctor and Amy in the Star Whale's mouth was taped at ITV Studios in Cardiff. The next day, the team repaired to Upper Boat Studios to film the TARDIS scenes. On the 9th and 10th, Neath Abbey in Neath posed as the Tower of London.

The remaining location days for The Beast Below were spent at the Johnsey Estates, part of the Mamhilad Park Industrial Estate in Pontypool. On September 11th and 12th, scenes in the voting booth were recorded. A number of Starship UK settings were represented on the 14th, including Mandy and Timmy's classroom, where two of the pupils were played by Gunn's children. The remaining days -- spanning September 15th to 18th -- were chiefly spent on the mammoth London Concourse set erected on location.

September 21st took cast and crew back to Upper Boat, for sequences in the Vator, the Tower of London, the observation deck, and the overspill pipe. The next day, Gunn's team moved to the Orangery in Port Talbot, for material in Buckingham Palace. The 23rd was again spent at Upper Boat, mainly for a variety of insert shots.

After the end of principal photography, Moffat made a number of amendments to the script for The Beast Below. Gunn's schedule did not permit him to participate in the necessary reshoots, and so Doctor Who veteran Euros Lyn -- who had most recently worked on The End Of Time, the final story of the David Tennant era -- was pressed into service. On November 2nd, Lyn filmed an expanded opening TARDIS scene at Upper Boat, with Amy floating in space. Two days later, more material was recorded at Upper Boat for The Beast Below, most notably a new sequence involving the Doctor and Amy in the window room. Pick-up shots were the order of the day at Upper Boat on both the 5th and 16th. In between, on the 12th, additional material of the Doctor and Liz 10 in the stardrive corridor was taped: in Moffat's original script, the two did not meet properly until Liz 10 rescued him and Amy in the overspill pipe, but he now intended their first encounter to occur much earlier in the episode.

• Doctor Who News.
• Doctor Who Magazine Special Edition #26, 30th December 2010, “The Beast Below” by Andrew Pixley, Panini Publishing Ltd.