Theory:Doctor Who television discontinuity and plot holes/The Dalek Invasion of Earth


 * If this is during the middle of Dalek history, why did the Daleks on Skaro not use disks on their backs to exit their city?
 * It's not the middle of Dalek history. The Doctor was clearly mistaken when he said this. The disks appear to only be needed by this group of Daleks for this particular mission of theirs. And indeed, in episode 2 the Doctor explains exactly this to Chesterton.
 * The Daleks in The Daleks (TV story) have just spent half a millennium cowering in a nuclear shelter- we know they had the technology to travel outside their city prior to this, from Genesis of the Daleks (TV story), irrespective of whether The Dalek Invasion of Earth (TV story) takes place before or after The Daleks (TV story)- but they simply haven't had cause to use that technology, or build it into their current casings- power drawn from the floor is more efficient. As Barbara rightly notes in the earlier story, it's only a matter of time before they get themselves organised and learn to travel outside the city.


 * The Slyther changes appearance between episodes 4 and 5 as the production team were not happy with its appearance.
 * Many species change their appearance easily.


 * When Ian and Larry meet Ashton the Slyther cries for the first time, over Chesterton's line. He does not pause nor otherwise express surprise or horror.
 * Animal noises at night are not necessarily unusual or alarming - until they get too close!
 * Its a production error. The sound effect was probably added in post production.
 * As Chesterton was talking to, and concentrating on, Ashton, he possibly didn't notice the Slyther's cry- or at least didn't register it enough to recognise it as something alien- until it began to call again.


 * Two studio technicians are visible outside the Dalek saucer in episode 2.
 * They could be prisoners of the Daleks.
 * Production error.
 * What is the point of answering 'Production error' to everything? Yes, it probably was but the whole point of this forum is to try to find an in-universe explanation for something that doesn't make sense. If we simply label everything as a production error then there's no point in this forum existing!
 * Not the previous respondent, but there is a distinction that is worth pointing out. A plot-hole is an error in storytelling logic that affects the cohesiveness of the story (essentially there's a flaw within the writing/editing that makes the story fail to make sense), whereas a production error is simply a special-effect failure or otherwise unintended "glitch" that simply went unnoticed at the time or was unavoidable due to the demands of time, budget or just basic filmmaking needs. The latter are catalogued elsewhere on the wiki and aren't really the preserve of this section of the forum, as there usually is no real explanation for it beyond "the production team didn't notice it / couldn't afford to correct it or make it better", and since (as in this case) they can usually be politely ignored without any detriment to the overall story, treating it it out as if it's a plot-hole can often just be evidence that the pointer is being a bit overly nitpicky or pedantic.


 * Jenny and Barbara have to hold their own neck restraints in place.
 * It is not a problem, it looks more like they are trying to pull them off or give themselves room to breath.
 * It's probably too heavy for them.
 * Budget restraints ???


 * When the Daleks are in Trafalgar Square, cars can be seen to drive past.
 * Pushing it somewhat, but these could (just) be Robomen on vehicle-based patrol, or the resistance cells making use of discarded vehicles, as Barbara and Jenny later do.
 * Unforeseen production error.


 * Pleasure cruisers can still be seen on the Thames.
 * Like the theory above, this could be a patrol boat used by the Robomen which resembles a Pleasure cruiser.
 * Similarly, it may have been hijacked by the robomen and actually was one prior to the invasion.
 * If they are still, they could be desserted.


 * Boom mike shadows are visible in episodes 3 and 6.
 * Could be trees or lampposts.
 * Productin error.


 * Why do the Daleks need intelligence tests to determine who can become Robomen when they are mindless zombies?
 * Allegedly, the more intelligent the human, the longer the Roboman will function.
 * Also, they may be required to perform mental calculations.
 * Or possibly this test is to remove the clever ones?
 * It's an extension of the Dalek obsession with purity. They are so fixated on ensuring everything about them is "pure" that they even screen individuals they are planning to reduce to brain-wiped slaves for intelligence just to make sure they're getting "pure" robomen without any "substandard" individuals getting mixed in. Sure, it's based on poor logic and kind of pointless -- but bigotry so often is.


 * Just what is the Dalek doing in the river in episode 1?
 * The Daleks are in Dalekanium shells, and therefore cannot distinguish between air and water. The Daleks are probing the Thames for some reason; possibly a scientific expedition- are the fish a threat to the invasion?! or it is searching for the suicidal roboman's body.
 * Quite probably some of London's bridges will have been demolished in the anarchy and invasion, and the Dalek is too impatient to bother crossing the nearest one in order to join the patrol. At any rate, it makes for a nice, early gesture of power and adaptability to the critics of Dalek mobility.
 * It is patrolling the river to ensure that no resistance or renegade operatives are making use of it. Since it is basically a highly-advanced alien battle-tank, it is presumably watertight (or at least, watertight enough that a body of water such as the Thames poses no problem for it); ergo, it can traverse underwater, which is particularly useful for stealth purposes, as anyone travelling on or near the surface of the river may not expect Daleks from underneath them.


 * The Black Dalek, before addressing the humans, clears its throat.
 * Who says the Kaled mutants don't have throats of some sort at this point in their development?


 * Why did the Daleks locate their mine in Bedfordshire rather than somewhere where the Earth's crust is thin?
 * How do the Daleks know where the Earth's crust is thin?
 * They probably choose a small area that would have little resistance; if they drilled in New York there may have been more resistance.
 * They were making use of the shaft that had been drilled a century earlier by the abandoned Inferno project.


 * During the first episode, while the Doctor and his companions are exploring their materialization place next to the Thames, the TARDIS windows are clearly propped open (inwards). Examples are at 2 minutes 12 seconds through 2 minutes 16 seconds, and elsewhere during the same scene. Were they just traveling through space and time with the windows open?
 * The TARDIS exterior faithfully matches a genuine police box - the windows are seen to be open in other early stories such as The Web Planet. The TARDIS shell is clearly not as simple as a wooden exterior, which would imply that it cannot be airtight. The Doctor later describes to Donna that there is a shield protecting the interior. It has been stated that the interior is in another dimension to the exterior (such as The Robots of Death).


 * After taking Barbara and Jenny prisoner, the Dalek that takes them across the control room of the Dalek saucer can be seen bumping into the Black Dalek.
 * Even murderous killing machines can be clumsy sometimes.


 * In episode 4 when they meet Ashton, the interior is seen to have a window - something not seen on the exterior.
 * Not on the side we see.


 * In the prison where the Doctor is held on the ship, another set behind the railings can clearly be seen, complete with Daleks moving about.
 * It's part of the same ship, which of course contains Daleks.


 * At one stage in episode 2, a Dalek can be heard saying "All" - the start of the next line (This is because it was pre-recorded, and couldn't stop the recording in time).
 * The Dalek was saying something and was interrupted.


 * The paint design of the Black Dalek changes after episode 2.
 * The first one was the commander of just the flying saucer, the second one was in command of EVERY Dalek on Earth


 * The use of cardboard Daleks outside their ship.
 * Budget restraints.


 * This isn't really a continuity error. They're meant to represent Daleks, just as the high-quality models (and later CGI) are; high-quality Dalek models (and CGI Daleks) are not Daleks either.


 * During episode 5, when the Black Dalek moves through the door, a production assistant is clearly visible to the Dalek's right.
 * A Human Slave.
 * Production error.


 * The 'It is forbidden to dump bodies in the river' sign is visible during the miners' revolt in episode 6.
 * There's no reason to assume they don't have the sign posted in multiple places.


 * If the Daleks are drilling to the Earth's crust, wouldn't that blow it up?
 * They have other methods than the ones used in Inferno. The Doctor mentions that they are manipulating living energy to avoid explosions.


 * Judging by what Susan says to Tom about 'Grandfather getting old now' and her needing to look after him, it seems that she doesn't know about regeneration.
 * Perhaps it would be hard for her to explain regeneration to Tom or perhaps she knows when he is going to regenerate and she wants to be with him. Also, she does not know for sure that he will regenerate into a younger body.
 * All she says is that he's getting old now, which does make things physically difficult for him at times. This makes no implications whatsoever other than that Susan cares about the Doctor's well being.
 * More often than not, after regeneration, the Doctor has been vulnerable and depended more than usual upon the help of his travelling companions to get him through the difficult time- his fourth, tenth, and fourteenth regenerations are particularly clear examples. "Grandfather's old now- he, he needs me," as Susan says, without further explanation, can just as easily convey "I know I can't explain this to you, human, but I have to stay with my grandfather because he's so old now that he might well regenerate soon, and then he'll need someone to take care of him", as it can mean anything else.
 * There is no overly convincing way to square this point with later continuity, but it may be that Susan believes the Doctor is in his final incarnation, or at least close to the end of his cycle. The Morbius mind-bending sequence implies many previous regenerations, and Susan may be unaware that the 12-regeneration limit does not necessarily apply to the Doctor (though for that, and other controversies, it is perhaps better to pretend that "Mawdryn Undead" never existed...).
 * A Time Lord can also choose not to regenerate, so for all we know the Doctor may have expressed the intention of making his life with Susan his swansong (we know he has had a dark past...), before Ian and Barbara helped him get in touch with his heroic side and thus gave him new purpose.
 * The recent episode Twice Upon A Christmas retroactively makes it a plot point that the First Doctor never intended to regenerate, thus making this a more than ideal explanation, albeit we had to wait over fifty years to get it.
 * But, this contradicts everything in The Tenth Planet. There is no evidence to suggest that the First Doctor did not want to regenerate. The First Doctor even says "Its far from all over!"
 * Or perhaps she genuinely doesn't know. The series, at any rate, offers no canonical explanation of who or what Susan actually is.
 * TimeLords do get old.
 * Just because he can regenerate does not mean she would not look after him whilst he is in this "old" stage of this body. Naturally she would a) not want him to regenerate earlier than necessary (so she looks after him) and b) want to be there with him when he does regenerate so she can support him.
 * Key words here: "he's getting old now". The fact that he can regenerate later is irrelevant to this particular conversation; as far as Susan is concerned, he is getting old and needs help "now" at this particular moment.
 * In any case, as events show, this is really Susan just making excuses. She's in love with David and really wants to stay, but feels guilty for doing so because she also feels that her grandfather needs her and/or is afraid of hurting him by leaving. It's not about whether or not the Doctor can regenerate; it's about Susan really trying to talk herself out of her desire to stay as much as convince David. In this light, the Doctor closing the TARDIS doors is him basically saying "Susan, don't worry about me, and don't give up what you really want just for my sake. I'll be fine, go and live your own life."


 * When Tyler and the Doctor are hiding behind the walls, the last Dalek to pass by has the eyestalk pointed in the Doctor's direction, yet he does not notice Tyler or the Doctor.
 * There have been many Anti-Dalek attacks during the occupation; it is likely that many Daleks have been damaged (this one has poor sight from damage to the eyestalk).


 * When Barbara and Jenny are taken to the Dalek command centre, they devise a plan against the Daleks. They talk in full voice, while the Dalek guard is directly behind them. Its only response is a command to 'stop talking'.
 * As the Dalek that comes out of the river in episode 2 says they have heard in the time that they have controlled the earth many similar plots to over throw them that have all failed so they have probably got to a point where they don't pay any attention to them any more since they know that they are going to fail.
 * Possibly more of a production error, or an expediency to compensate for poor studio microphones. The viewers are supposed to suspend disbelief and assume they are whispering almost inaudibly (even though they clearly aren't).


 * In Episode 5, the Dalek supervising the mine clearance has broken speech-synch lights, and instead chooses to wiggle its eyestalk about while talking.
 * As stated above many Daleks are likely damaged after resistance attacks, and the Dalek may wave its eyestalk the same way a human slave-driver would wave their hand as another way of saying "hurry up!".


 * The Daleks have invaded Earth for their plan because they say that no other planet has a magnetic core, but magnetic cores are common and all the planets in Earth's Solar System have one.
 * Of the terrestrial planets, Earth has the largest magnetic core, and the largest magnetic field.
 * See The Stolen Earth for an alternate explanation.
 * Which would suggest that the Skaro system is close to our solar system, or at least the closest that contains an earth-like planet. One might ask why they didn't remove the core from their own planet? On the other hand, the core may be only one reason for choosing earth, and not necessarily the first one. If the events of The Daleks were in fact in the past relative to Earth, as the Doctor states, the Dalek survivors passed on memories of the travellers from Earth. So perhaps the Daleks regard Earth as a threat to their empire.
 * Or it is simply easier to invade Earth or the local species are a more durable work force.
 * In The Runaway Bride, the tenth Doctor learns that a Racnoss ship had been hidden at the centre of Earth at the time the planet formed. This could have resulted in Earth's magnetic core exhibiting truly unique properties.
 * In The Runaway Bride, the tenth Doctor learns that a Racnoss ship had been hidden at the centre of Earth at the time the planet formed. This could have resulted in Earth's magnetic core exhibiting truly unique properties.


 * I don't see what issue there is with the dating of this episode. All they say is that the invasion started ten years ago, not that the Daleks have been on Earth for ten years. They began with a meteorite bombardment and releasing a plague. There was no active opression or robo men for a long time. It's more than conceivable that calanders would have been printed. The humans might not even have known their misfortune was due to alien intervention until the Dalek's actually appeared. So taking that the meteorite bombardment began in 2157 (per the Dalek's master plan) and after seven years of global attacks, the Dalek's finally land at 2164 (when the warehouse is abandoned with the calender Ian finds) you have no continuity errors. In fact, if anything, it makes more sense. A three year operation to enslave the population and mine to the core makes more sense than a ten year one for a species as advanced as the Daleks.