Theory:Doctor Who television discontinuity and plot holes/The Android Invasion


 * The U.K. has never had a manned space program.
 * In the Doctor Who Universe it does.
 * The story was set approximately 5 to 10 years ahead of original broadcast date. At that time, the UK could have had a manned space program (in reality it didn't).


 * Why do they need to destroy their duplicate village?
 * Why shouldn't they? It's safer not to leave random clues as to your plans laying around, even if you think its unlikely someone will find them.


 * Chedaki and the rest of the fleet are left unmentioned at the end of the story, especially odd since the Doctor says the Kraals could take Earth by force if they wanted to.
 * The Doctor says this to the false Sarah, however, and might intend it as a gross exaggeratrion of the Kraals' military capabilities, only intended to lull them into a false sense of security (that he is not onto their actual, stealth-based plans). Given their dying planet and generally sneaky tactics, it is probable that Chedaki's fleet are not all that impressive, and opted for easier pickings when Earth proved not to be such a pushover.
 * The Doctor at one point mentions the Kraals can't use their more advanced weapons to bombard the Earth, otherwise it would ruin it the point they couldn't use it either. This suggest is less they could take the Earth by force, more they could flip the board so no one wins if pushed, and they're actually military would lose (say due to lack of numbers or resources) a more conventional fight.


 * As the Daily Mail reviewer in 1975 wondered, how can the Doctor use his own android against Styggron if all the androids have been neutralised?
 * The neutralisation of the androids did not require a continual interference field to be maintained. Once it had been switched on the androids automatically deactivated. All the Doctor had to do was switch-off the field and then re-activate his android.


 * Crayford has never looked under his eye patch to find his intact eye! Nobody at Space Control notices this acquisition, either.
 * The Doctor references that Crayford had been brainwashed. No one at Space Control has time to notice any changes before the invasion begins.


 * In part four, an android version of Sarah appears just after the real Sarah runs off after being confronted by an android version of the Doctor by the TARDIS. When the android Doctor appears inside Space Control, this android Sarah has vanished, and never appears again in the story.
 * This android was not necessary at space control. It had instructions to infiltrate another installation.


 * Would Crayford really possess enough first hand information to recreate the village and the surrounding forest so completely?
 * The mind analysis would provide more details than a human would consciously remember.


 * And given the Kraal's remarkable attention to detail, would they have made such rudimentary errors with the fresh-mint money and the calendar?
 * No one is perfect.


 * Additionally, wouldn't there be every chance that his intel on the personnel present and the running of the space center be very much out of date after a two year absence?
 * He has recently re-established communication with Earth, as is indicated.


 * What is the point of the elaborate village mock-up when they are only taking four androids with them anyway and their intentions are take over the whole planet, not just one small part of England?
 * The invasion would have happened piecemeal. They would have begun with the space center, set-up a workshop for making more androids, taken over the village and started working gradually outward from there.
 * They also are shown to have taken more than four androids.


 * How did the Kraals know to bring a duplicate android of Colonel Faraday as opposed to the Brigadier? They could not know the latter would be away at the time of Crayford's landing. Also, how did they know that he and Harry Sullivan would be first into the rocket ship and hence would be the very androids necessary to replace them.
 * These details, as well as Crayford's presence, had already been discussed and agreed upon in one of Crayford's earlier radio conversations.
 * Alternately, the form of the androids on board the rocket ship had not been fixed yet, and Styggron had the equipment to mold their shape to whatever form he needed once he'd captured whoever came aboard first.
 * It's a pretty logical conclusion for them to have reached. Harry is one of the first into the ship because he is the medical officer, as stated. Faraday is the senior officer, hence is welcoming back the "returning hero".


 * If all Sarah Jane's knowledge was absorbed into the Kraal computer, why not her dislike for ginger beer?
 * No process or equipment works perfectly, as seen by some of the odd details and behavior earlier in the story.


 * Sarah putting her key in the TARDIS lock interrupts the 'pause control' so it continues on its journey to Earth. This seems a potentially very dangerous feature for the TARDIS. If there hadn't been any other means of transport available the Doctor & Sarah-Jane would have been stranded forever.
 * The TARDIS has a mind of its own and knew there was another means of transport available. Alternately, the Doctor had a chance to return to the TARDIS before being captured and set the controls to do this, so-as to prevent a duplicate gaining control of the TARDIS.


 * It is never explained why the TARDIS happens to materialise on the Kraal home world when they are on their way to Earth. If it is just a case of the TARDIS going astray as usual then it is quite a coincidence that they land smack-bang in the one part of the planet which so closely resembles Earth.
 * This is just another example of the TARDIS's 'visual orientation circuits' (See Horror of Fang Rock) going wrong. They catch a glimpse of the Earth-like scene and mistake it for their destination.


 * Why do they have people from the village - it's stated that they wanted the androids to take over key positions - ordinary people hardly qualify as people in high positions.
 * The android versions of ordinary citizens were built as test subjects for the android-making process.


 * Why doesn't Sarah tell the Doctor about the fake Doctor and Sarah when she meets him at the UNIT base in episode 4?
 * She was panicked and they were in somewhat of a rush. She also may have assumed he had already figured out they'd made copies of them.


 * Why is he jumping off the cliff in the first place
 * The androids are not necessarily sentient, and this one just seems to be running wild.
 * This android is malfunctioning. Testing of the androids was just wrapping up when the Doctor arrived.


 * The Doctor now carries a portable robot detector. We'll assume he devised this after having realised how handy one of those would have been in "The Chase". Odd, then, that such a convenient little (plot) device doesn't even get a mention in "The Androids of Tara" or (by the same author, mark you) "Destiny of the Daleks".