"The Girl in the Fireplace" began as an idea Russell T Davies had while working on Casanova, to somehow include the character of Jeanne Antoinette Poisson, otherwise known as Reinette ("little queen") or Madame de Pompadour, in a story that showcased The Turk, a mechanical wonder of the age.

The Turk was an animatronic man (head, arms and torso) that appeared to possess the uncanny ability to play chess. It toured the royal courts of Europe, confounding onlookers by beating them in every game. It was eventually discovered that this was no super-intelligent proto-robot, as there was a human grandmaster hidden inside The Turk's workings. But Davies wanted to retell part of that story, giving the clockwork automaton a more sinister motive.

(Incidentally, Neil Gaiman made a more explicit use of The Turk in "Nightmare in Silver," although in that story he was a Cyberman.)

Here are a few other things that you should keep an eye out for, the next time you watch.

(The episode is available on iTunes and Amazon.)

Early on, as the Doctor explores the spaceship with Rose and Mickey, he notes, "Dear me, had some cowboys in here! Got a ton of repair work going on," then uses the same phrase as he scans Reinette's mind. The phrase "had some cowboys in here," always said with a disapproving sigh, is a British idiom as used by builders and car mechanics alike. The "cowboy" in question isn't a fellow on a horse with a hat; it's a disapproving term for a sloppy workman. The inference being that your previous repair was badly done, and this craftsman (who would never do such a poor job) will have to fix their errors as well as sorting out whatever your actual problem is. Sometimes it’s a genuine response to shoddy work, but it can also be used to gouge up the price of labor.

As if to illustrate this point, the phrase appears again, out of the mouth of the Eleventh Doctor as he pokes around Amelia Pond's bedroom looking at the crack in her wall.

The original intention with the clockwork androids—actual working props designed by Neill Gorton of Millennium Effects and constructed by Richard Darwen and Gustav Hoegan—was that they would be hidden in plain sight, dressed in the same style as everyone else, but that their wigs would cast a shadow across their faces until the time came for their big reveal. In a conversation with producer Phil Collinson the production team realized there would be very few camera angles that would consistently hide their faces and not those of everyone else, hence the carnival masks.

Alternative titles considered for the episode include "Madame de Pompadour," "Every Tick of My Heart," "Reinette and the Lonely Angel" and "Loose Connection." This story had been planned as the second in Season Two, replacing "Tooth and Claw" as the historical counterpart to the extreme future depicted in "New Earth." However the episode order was changed when it became clear Steven Moffat had written a script that took the Doctor into new areas, emotionally speaking. The story was moved to the spot after "School Reunion," in which Sarah Jane Smith makes her return, to quell any fears about the Tenth Doctor departing too far from fan expectations.

It's David Tennant and Sophia Myles on set filming The Girl in the Fireplace, which was first broadcast #OTD in 2006… #DoctorWho #DrWho #fandom #whovian #BTS #BehindTheScenes

A photo posted by Doctor Who Official (@bbcdoctorwho) on May 6, 2016 at 1:45am PDT

Paul Cornell deserves credit for creating two items of Doctor Who mythology cited here by Steven Moffat, both of which made their first appearance in his 1992 Doctor Who: The New Adventures novel Love and War. This was the source for the nickname “the Oncoming Storm,” as used by the Draconians in the novel, but by the Daleks in the TV series. It is also the source of a gag Steven Moffat seems to be exceptionally fond of. Young Reinette asks the Doctor what monsters have nightmares about, and he replies "Me!" and laughs. That joke also appeared in a short story called "Continuity Errors" that Steven wrote for the Doctor Who fiction collection Decalog 3: Consequences.

Another aspect of the story that didn't make the final edit was that of the "Choleric Man" (played by Philip Harries), the owner of the horse that the Doctor rides through the mirror. He threatens whip his steed for running off, and the Doctor intervenes.

https://www.youtube.com/watch?v=Oj9IpD9BM_w

The gowns worn by Sophia Myles in this episode all have a fine history within the British television and film industry. Some of her dresses have appeared in, for example, the movies Aristocrats and The Madness of King George. One particular gown (as seem below when Reinette walks the grounds with her consort Catherine, played by Merlin star Angel Coulby) has the finest pedigree of all, having been first made for the 1982 Fifth Doctor adventure "Black Orchid." It later appeared on one of the extras in the video for Annie Lennox's song "Walking on Broken Glass."

[caption id="attachment_364516" align="alignnone" width="626"] 'Black Orchid' / 'The Girl in the Fireplace' (Photos: BBC)[/caption]

There were some problems with filming the horse jumping through the mirror, in that the crew could not bring an actual horse into Ragley Hall, Alcester (the location of the ballroom scene), and the stunt itself was initially considered too expensive to film. At first, this caused a rewrite for Steven Moffat in which he came up with two alternatives; the Doctor mounting the horse and being thrown off, thereby falling through the mirror (rejected for undermining the Doctor's heroic moment of self-sacrifice) and the Doctor smashing through the glass on his own, while the horse wanders off. Neither seemed satisfactory, so in the end, in order to make the horse jump happen, all the separate elements of the stunt—the horse, the mirror breaking and the background—were filmed in isolation and then edited together, with David Tennant's head being digitally jammed onto that of a stunt rider.

https://www.youtube.com/watch?v=I23kzao3EnQ

The Doctor's parting shot to the androids is "It's over. Accept that. I'm not winding you up"—an excellent pun, based on the clockwork nature of his adversaries and the British slang term "wind-up," meaning a deception or a trick. "I'm not winding you up" in this context means both "I refuse to recoil your spring" and "I'm not kidding."

Other rejected script ideas include a script rewrite that saw Reinette and the Doctor meet out of sequence, as would later happen with River Song. She would remember having met him at her convent school, and he would go there after the TARDIS leaves the spaceship that bears her name. This idea came from Audrey Niffenegger's novel The Time-Traveler's Wife, in which a man gifted with the power of time travel meets a woman and falls in love, but their various liaisons are chronologically out of synch. There was a second plot thread in which the androids were first attracted to Reinette's mind by the Doctor scanning it. Rose then offers her a gem that would erase the Doctor from her memory, leaving her safe, but she refuses, as she couldn't bear to forget him.

https://www.youtube.com/watch?v=3ao9-22T3d0

One thing to look out for is the decoration in the room in which Reinette has placed the fireplace for her home. When she's alive and the fire is lit, the room is bathed with a yellow glow and the panels look white and sky blue. After she dies and the room is dark, those blue panels take on a darker hue, and the whole wall starts to resemble the front of the TARDIS. Reinette must have come to appreciate the significance of blue and white squares from her reading of the Doctor’s memories.

NEXT: 10 Things You May Not Know About ‘Rise of the Cybermen’

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