The TARDIS lands on Apalapucia, a planet ravaged by a plague which is fatal to beings with two hearts. With the Doctor consigned to the Ship, his companions become separated across two time streams which move at very different rates. Amy is forced to venture into a medical facility, where she is stalked by Handbots carrying lethal medication. Meanwhile, the Doctor manages to synchronise the time streams, enabling Rory to go in search of his wife. But when he finally finds Amy, he discovers that she has been waiting thirty-six years for rescue -- and may no longer want to be saved.

Having contributed Rise Of The Cybermen / The Age Of Steel to Doctor Who's twenty-eighth season in 2006, Tom MacRae hoped to continue writing for the series. He next began work on an adventure called “Century House”, which was initially planned for Season Twenty-Nine and then deferred to Season Thirty, only to be replaced with Midnight. By 2010, MacRae had become acquainted with Doctor Who's new executive producer, Steven Moffat, who invited him to submit further ideas for the programme. MacRae decided to attempt a narrative in the tradition of Moffat's own time-bending stories such as 2006's The Girl In The Fireplace. He also wanted to focus on Amy Pond, and write an adventure specifically designed for her, as opposed to one which was suitable for any companion. As such, MacRae recalled the Doctor's description of Amy in her first story, The Eleventh Hour, as “the girl who waited”; this referred to the fourteen years which elapsed between her first meeting with the Doctor as a child, and his return to bring her aboard the TARDIS.

Moffat was intrigued by MacRae's proposal, which was entitled “The Visitors' Room”. One slot was still available for Season Thirty-Two at this point, and it was decided to commission MacRae's script as one of five contenders. Over the course of the writing process, “The Visitors' Room” came to focus almost exclusively on the Doctor, Amy and Rory while eliminating some secondary characters who were used to set up the premise. In particular, this allowed MacRae to introduce the aged version of Amy much sooner than had originally been the case. The result was more of a character piece, whereas the emphasis had originally been on the prison break elements.

The Handbots were first envisaged as cloaked entities whose hands emerged from the folds of their robes

Over successive drafts, MacRae's adventure went through alternative titles such as “The Visiting Hour” and “Kindness”, before The Girl Who Waited eventually proved to be the obvious choice. Another aspect of the story which evolved considerably was the Handbots, whom MacRae first envisaged as cloaked entities whose hands emerged from the folds of their robes. Later they became more explicitly robotic, although MacRae intended for them to wear various uniforms and, disquietingly, have actual human hands. At one stage, he included a scene in which a Handbot's hand was severed, but then began moving around on its own.

Moffat grew increasingly fond of The Girl Who Waited during its development, and he finally decided to schedule it as the tenth episode of Season Thirty-Two. As such, it displaced The God Complex, which became episode eleven. However, MacRae would now have to implement a significant change to his script. The production of the story would occur in parallel with Closing Time, which primarily featured the Doctor and reserved only a cameo appearance for Amy and Rory. The Doctor's role in The Girl Who Waited would therefore have to be correspondingly minimised. This practice of double-banking was necessary to ensure that there was enough time to make the thirteen episodes of Season Thirty-Two alongside the 2010 Christmas special, A Christmas Carol; a similar approach had been adopted for Midnight and Turn Left during Season Thirty.

To accommodate this requirement, MacRae revised his scenario to add the stipulation that the Chen-7 virus only affected beings with two hearts. This meant that the Doctor could be confined to the TARDIS for most of the adventure, whereas originally he had accompanied Rory into the Two Streams Facility. The Doctor's exchanges with Rory and Amy would now be delivered via Rory's spectacles, so that Matt Smith would only be needed for a couple of days' filming.

The Girl Who Waited was made as part of the sixth production block for Season Thirty-Two (albeit labelled “Block Five”). It was paired with The God Complex, and assigned to director Nick Hurran, who had previously recorded one of MacRae's scripts for Bonekickers. There was considerable discussion about the aged version of Amy, and whether she would be played by Karen Gillan or an older actress. Gillan herself was keen to tackle the role, and Moffat concluded that audiences would be less sympathetic towards the character if she were portrayed by somebody else.

The first footage shot for The Girl Who Waited was of the Check-In Girl, recorded at Doctor Who's regular studio home in Upper Boat on February 23rd, 2011. Hurran otherwise concentrated on The God Complex for the first two weeks of the block. Work on MacRae's story finally resumed with three more days at Upper Boat spanning March 1st to 3rd. The principal concern was material in the entrance corridor and the two visitors' rooms, although scenes in the airlock were also taped on the final day. March 1st marked the first on-set use of the Doctor's long green coat; on screen, it would initially be seen in episode eight, Let's Kill Hitler, which had not yet entered production. Its introduction was part of a plan to evolve the Doctor's appearance throughout Smith's tenure. Meanwhile, it was only at this stage that the script was amended to include the scene in which a Handbot exposed the secondary delivery system in its head.

On March 7th and 8th, Hurran's team was at work at the Millennium Centre in Cardiff Bay, for material in the check-in area and the coffee bar. The 9th was spent at Uskmouth Power Station in Newport, which offered spaces suitable for the industrial area and the engine room. Cast and crew returned to the Millennium Centre on March 10th. On the 11th, sequences in the surreal mansion grounds -- which had originally been written for a forest environment -- were filmed at Dyffryn Gardens in St Nicholas. The week ended back at Upper Boat on March 12th, for the start of recording on the gallery set.

After a day off on Sunday the 13th, the remaining scenes in the gallery were taped at Upper Boat on March 14th and 15th. The latter day also saw work in the gate area, along with some inserts. On the 16th and 17th, the venue for sequences in the engine room quarters and the service area was the Johnsey Estates in Pontypool's Mamhilad Park Industrial Estate; additional pick-up shots were also recorded there. Hurran filmed TARDIS scenes and more inserts at Upper Boat on March 18th. Given the volume of material which featured the Doctor on his own, the standing TARDIS set was also required on the 23rd. The final recording for The Girl Who Waited took place at Upper Boat on April 26th, and consisted of the footage necessary for the “ghost” effect which depicted the Chen-7 patients' overlapped timelines.

The adventure originally closed with the Doctor ruminating that he couldn't keep upending Amy and Rory's life

There were numerous cuts to The Girl Who Waited in editing. When Amy entered the check-in area, she learned that it was a replica of the Mayfield Avanti Spaceport. She later asked Interface for a picture of the real spaceport, which helped her deduce the location of the temporal engines by noticing that there was an extra door in the simulation. The adventure originally closed with the Doctor ruminating that he couldn't keep upending Amy and Rory's life; this would have foreshadowed the end of The God Complex, in which the Doctor returned his companions to Earth. The biggest change was to the sequence of events at the heart of the episode. As scripted, Rory encountered the older Amy before the young Amy was shown entering the gardens. Consequently, the depiction of Amy venturing towards the temporal engines and leaving a note for the Doctor in lipstick was meant to explain the outcome that viewers had already witnessed. The final version instead presented events in a more chronological order.

The Girl Who Waited aired on September 10th, and saw Doctor Who moving to the later time of 7.15pm. This was to accommodate its new lead-in, the ninth season of the ballroom competition Strictly Come Dancing.

• Doctor Who Magazine Special Edition #30, 21st March 2012, “The Girl Who Waited” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #69, 2018, “Story 221: The Girl Who Waited”, edited by John Ainsworth, Hachette Partworks Ltd.