Theory:Doctor Who television discontinuity and plot holes/Attack of the Cybermen


 * How did the Cybermen get into the TARDIS before the Doctor arrived. 
 * The Cybermen might be advanced enough to break into the Doctor's TARDIS. It's also possible that the Doctor simply forgot to lock it, which he's done in the past.


 * Why do the Cybermen let the Doctor tamper with his controls when they are holding Peri?
 * Odds are they aren't familiar enough with the TARDIS to realise that the Doctor could tamper with its circuitry from the room they locked him in.


 * It is established that the Cybermen went to Telos after Mondas was destroyed to use the freezing chambers. So why are there Cybermen in the freezing chambers in this story? They haven't come there yet.
 * Yes they have. They have been on Telos for ages. The ones we see in the beginning are probably survivors from The Invasion who have somehow got in touch with the rest of their kind.
 * Actually, it is clearly established that the Cybermen on Earth have traveled back in time to 1985. The Doctor is concerned that the Cybermen have discovered the 'secrets' of time travel, to which Flast (while they are both captive on Telos) assures him that they have only captured a time vessel, but that they don't understand why or how it works, just that it does.


 * It seemed like a very crude plan for the Time Lords to send him to stop the Cybermen against his will, without him knowing what he has to do?
 * He has been sent on this sort of mission before (TV: The Brain of Morbius)


 * Cybermen can not feel emotions, meaning they can not laugh, so when the Doctor threatened not to co-operate if Peri is killed and a Cybermen told him they'd kill him if he didn't, that Cyberman smirked when they said they'd still have his TARDIS.


 * The Cyber Controller has a bit of a tummy on him.
 * He also has a larger than usual head. Both may be designed to hold extra circuits or wires that make him a Controller instead of your average Cybermen.


 * The Cyberman guarding the Doctor and Flast tries to extinguish his flaming arm by batting it with his gun.
 * The Cyberman's head that the Doctor investigates, searching for the distress signal, contains no organic part.
 * It does at least have a silver chin, a nice piece of continuity.
 * Remember that the Cryons have been sabotaging the tombs; the cryostasis system in that cell seems to have failed, and any organic parts of the Cyberman would probably have rotted away.


 * Towards the end, when a Cyberman realises that Cyber Control is soon going to blow up, he makes 'leg it' motions to his companion.
 * Why does the Doctor berate himself for misjudging Lytton when they didn't even meet in Resurrection of the Daleks ?
 * An untelevised adventure, perhaps?
 * And is he really that nice anyway?
 * The audience knows how nasty Lytton really is, but the Doctor only has this story (and a brief sighting of him in Resurrection of the Daleks) to judge him on. On that basis, the Doctor's comments make more sense, even if his conclusion is a bit hasty.


 * Why is Lytton's distress signal still transmitting some months after the Cryons have made contact?
 * How do they do this, given that they are in the future?


 * How was Lytton able to build a sophisticted communications system with 1985 components?
 * Why does Lytton abduct Griffiths when he could have taken his policemen with him?
 * How can you turn a comet (a large snowball) into a bomb?
 * You don't have to actually turn it into a bomb. Just steering it into Earth would leave the planet in such a bad state that they wouldn't be able to organise any sort of defence against Mondas the following year.


 * Why do the Cybermen want to destroy the surface of Telos?
 * Why do they leave the Doctor in a room full of explosives?
 * If you paid attention to the episode, the Cryon that the Doctor was locked with said that the Cybermen left the explosives there, because they were useless in temperatures below 0, and the Doctor was locked in a freezer. The real question is why did the Cybermen let him keep his sonic lance.


 * There's at least one Cyberman left in the TARDIS.
 * Not necessarily - it might have left the TARDIS in between its arrival on Telos and the Doctor reclaiming it. A better question might be why it isn't better guarded, considering what a vital asset it would be to the Cybermen...
 * And even if it is, that's not necessarily a plot hole. It could have wandered around the TARDIS for decades until dying, or escaped later when no one was looking. Plus, with Kamelion dead, the Exxilon and the leftover Earthshock Cybermen needed a 4th for their nightly bridge game.
 * And even if it is, that's not necessarily a plot hole. It could have wandered around the TARDIS for decades until dying, or escaped later when no one was looking. Plus, with Kamelion dead, the Exxilon and the leftover Earthshock Cybermen needed a 4th for their nightly bridge game.


 * The Foreman junkyard doesn't resemble either the version seen in An Unearthly Child or Remembrance of the Daleks.
 * However, the story takes place in 1986, at least 23 years after the events of those stories, and as such the junkyard could have undergone any number of physical changes or even relocated in that time.