Theory:Doctor Who television discontinuity and plot holes/The Girl in the Fireplace


 * In the beginning of the episode shown 18th century French but after that, there were shown scene of space ship and appear title saying 3000 years later. So in fact, story setting should the 48th century, not 51st century (although this is clarified when The Doctor mentions to Rose that it is about "3000 years into your future, give or take").


 * The behaviour of the fireplace window is quite strange. When the Doctor is talking to Reinette through the fireplace, the time in France and on the spaceship is synchronized, as it is when he is on the French side of it. However, when he's on the ship side and not talking to Reinette, time flows much faster (and at a variable rate) on the French side. Interestingly, we never see any hint of this effect with the other time windows - Reinette doesn't seem to go missing when she walks through to the spaceship.
 * The Doctor states that there is a "loose connection" and so it's not like so many seconds to so many minutes. This would explain why Rose shouts that the Doctor would be furious if Reinette went through to the spaceship as the group don't know exactly how much time would have passed. As for the other windows not time jumping, perhaps it's only the fireplace that doesn't work properly. When people are communicating through the windows (like when the Doctor and Reinette are at the start of the episode) maybe the window recognises this and lets time flow correctly.


 * Why doesn't the TARDIS translate Reinette saying "Monsieur"?
 * This is standard French and very nearly all English people know what Monsieur and Mademoiselle means so maybe the TARDIS recognized that Mickey and Rose didn't need this translated. Or, as later established in The Fires of Pompeii, she may have used an English word, such as "Sir" at this point, for some reason. It could have also been a decision to reinforce what is said about her being French. Just because we hear Monsieur doesn't mean she said it.


 * As Mickey asks, just what is the horse doing on the spaceship? Did it just happen to walk through one of the time windows (and, if so, why was that window left wide open for anything to walk through) and avoid being taken apart for parts by the robots, or was it already on the ship and somehow avoided being taken apart for the year since the ship was stranded, and didn't show up when the Doctor scanned for lifeforms.
 * It is never made clear exactly when the horse walked through and it is stated that the robots needed Reinette's brain for their ship and so they could have just dismissed the horse if it wondered through after all but that one repair had been made. The Robots kept entering at different points in her life and didn't close all of them off. It's explained in deleted scenes, the horse had run from it's abusive owner, who asked the doctor if he'd seen it. The doctor then found it, not wanting it to die, took it into the ship himself.


 * Why doesn't the service robots' programming prevent them from using the crew for parts?
 * It is entirely possible that it never occurred to the crew that the robots would try to use them for parts, so they never thought to rule it out in the programming. It's also possible that in addition to the damage to the ship, the robots themselves were damaged and acted a bit outside of their normal programming, or they could just have been defective all along without anyone noticing until it was too late - perhaps they were new models without all the bugs worked out. A less likely but still possible explanation is that there was some sort of sabotage at work. The crew were quite possibly killed in the damage to the ship, the robots could have been utilising their assets.
 * Tardisode 4 shows that at least one crewmember was still alive when the robots came for repair parts.


 * If, as the Doctor says, the fireplace window is offline when the robots attack the party then how does the audio link clearly pick up Reinette's words shouted through the fireplace, which is nowhere near the window? Especially as there is no background noise of party goers screaming in this scene.
 * It's possible he turned off the ability to go through them but not the sound.


 * What happens to the robots after the Doctor leaves, since space age clockwork in France in the 18th century would change history?
 * It is likely that the robots would be burned or otherwise destroyed, as the people of 18th century French would have been terrified of the robots coming back to life. Also, space-age clockwork would just look like clockwork to them, which isn't anything new in the 18th century.


 * Why build the robots with their blades, knifes, knock out syringes or short range teleport what exactly is them point of any of them?
 * They are repair robots so the blades and knives would have been understandable (as of use for cutting ropes and wires). The knock out syringe could have been used in the event of coming across a 'stow-away' or hi-jacker, unbeknown to the programmers that they could uses the little imagination that they had to take over the ship themselves. The short range teleport would have been useful if they were in a place of danger such as a pipe leak, if there was something that was in urgent need of attention or simply if the crew needed the robots to do something for them and get it to them in as little time as possible. It's possible, and in fact likely due to the fact they knew how to keep a heart, eye, and presumably brain alive, that they were also medics, explaining the anaesthetic, and the teleport.


 * Rose and the Doctor's emotions seem very odd near the end of this episode when the time windows are broken and they are separated, in DW: Doomsday when Rose is sadly but safely trapped in Pete's World away from the Doctor they both express depression for a long time but in this episode Rose is trapped on a ship with only the company of Mickey and is likely to starve or die of thirst yet the Doctor seems fairly okay and Rose only slightly worse, why is this?
 * Mickey and Rose were in no danger: at any time they could enter the Tardis, lock the door and live in the Tardis where they will have food and drink for an eternity. As for emotions, in this story Rose kept hope that somehow the Doctor would eventually make his way back to them through his own means; the Doctor was spirited by the presence of Reinette) Also, by the end of the series it is heavily implied the Doctor and Rose were in love, but a considerably amount of time and critical moments of dependence occured during the few episodes after this one. Particularly, the Idiot's Lantern, when the Doctor had to seriously consider Rose's departure, and the impossible planet, when he was happy with the idea of living with her for the rest of his life.


 * The Doctor knew that time on the other side of the windows flowed faster than on the ship. When he left with the promise to return, why didn't he use the TARDIS to come back to the point shortly after his departure, instead of risking to be late?
 * He probably just didn't think of it in the heat of the moment. The Doctor has been shown to make mistakes many times—even though he's a Time Lord, he's still "only human".