Theory:Doctor Who television discontinuity and plot holes/Castrovalva


 * The entire premise of this story is incredibly tenuous. Why does the Master bother to contrive the whole of Castrovalva for the Doctor's benefit when he could have killed him any one of a dozen different ways without the trouble? Once again we see the Master going to ludicrously elaborate lengths to ensnare and eliminate the Doctor having been happy to simply kill him in the scene/episode/story directly beforehand.
 * The Master does not want to simply kill the Doctor. Over the course of the series, it is established that the relationship between the Doctor and the Master is far more complex than that. Both before and after this story, the Master has many opportunities to kill the Doctor of which he does not avail himself.


 * "Event One" appears to be a reference to the Big Bang — the creation of the universe. However, it is repeatedly described in this story as "the creation of the galaxy", which is believed to be a quiet, tranquil coalescing of hydrogen predating the first stars rather than a dramatic cosmic event.
 * The term "galaxy" is used off an on throughout the series to refer to the Universe. It's an expression in such instances, rather than a specific astronomical phenomenon.
 * This is still a problem, because "Hydrogen In-Rush" does not at all describe the Big Bang, because no hydrogen (or anything else) existed before it. The first hydrogen atoms were created by the Big Bang, not the other way round.
 * To give the script the benefit of the doubt (and this is desperate), if you're going backwards in time, the primordial hydrogen would appear to be in an in-rush towards the plasma ball.


 * How does hydrogen enter the sealed TARDIS? And the hydrogen is visible (gaseous hydrogen has no colour).
 * The gas in question is never stated to be hydrogen. The superheating within the TARDIS at this time would undoubtedly cause some measure of condensation and rapid evaporation, causing water vapor - similar to the condensation process which occurred in the TARDIS in TV:Marco Polo (TV story).


 * How can the temperature within the TARDIS, which presumably has its own air-conditioning system, rise?
 * Extreme heat can cause even an air-conditioned interior to become hotter. The heat generated during Event One would be phenomenally high.


 * The security guards up on the radio telescope never come down.
 * They would have no reason to leave their post if other guards were handling the situation on the ground.


 * When the Doctor levitates in the Zero Room his coat tails levitate too.
 * In an anti-gravity field or something similar, his coat tails would be expected to levitate.


 * In the very last scene a fence is visible on the deserted planet.
 * Deserted means there was someone there, but no longer, so an old fence wouldn't be out of place.


 * Moments after the Doctor has regenerated, Adric is using the term and apparently showing some knowledge of the subject, yet there's no indication he should know about regeneration at this point.
 * Adric is an inquisitive person, and had ample opportunity to learn about the process from the Doctor, Romana, or K-9 during his travels with them.
 * He also had an unheard conversation with the Watcher, who was specifically there at that point in time to aid in the regeneration.


 * Romana's room is used in this episode despite being jettisoned in TV: Logopolis.
 * Just because The Doctor got rid of it does not mean that he did not go back and get it between the events of The Keeper of Traaken and Logopolis. He may also have done this to spite the Timelords, showing that despite Romana no longer being on the Tardis. She will allways be there, just in their memories. Or he may have done this in case Romana returned, as K9MKII had plans for the Tardis, he presumably knew that she could return, and kept it, just in case.
 * And, as hinted at in many episodes (and novels, etc.) and finally confirmed in The Doctor's Wife, the TARDIS herself keeps various rooms around as "records" and can generate whichever ones she wants.
 * And, as hinted at in many episodes (and novels, etc.) and finally confirmed in The Doctor's Wife, the TARDIS herself keeps various rooms around as "records" and can generate whichever ones she wants.


 * It's understandable that the newly-regenerated Doctor doesn't see the resemblance of the Portreeve to the Master, but why don't Nyssa and Tegan?
 * He is in disguise, and further has been shown to have significant capabilities to control the human mind.
 * Nyssa isn't a human though, and should probably be able to recognise her own father's face more so than Tegan.
 * The Master is, well, a master of disguise. The whole point is that he is able to disguise himself in a way that even people who know what he otherwise looks like might struggle to recognise him.