Theory:Doctor Who television discontinuity and plot holes/The Five Doctors


 * Why does the First Doctor look completely different, and the Second and Third Doctors look older than they were when they regenerated? (I know the production reasons, I want to know if there is an in-story explanation. I guess you could say that the Second Doctor didn't actually regenerate at the end of The War Games and this is part of the Season 6b theory but it doesn't explain it for the Third Doctor.)
 * This is speculative, but Time Lord ageing does not appear to operate in quite the same way as ours. River Song speculates (and apparently acts) the ability make herself look younger, as she in fact ages, in order to shock, and various incarnations of the Doctor go through allegedly lengthy periods off-screen with only minimal signs of ageing. Notably, for instance, the 13th incarnation (11th Doctor) sustains two hundred years between The God Complex (TV story) and Closing Time (TV story) without apparent physical ageing of any sort, whilst a mere few years prior to this, the 11th incarnation (10th Doctor 1.0) is physically shattered and ancient, after a mere century added to his biological age by the Master in The Sound of Drums (TV story).
 * Arguably, then, the inference is that artificial ageing - rapid, the consequence of time manipulation - see also The Leisure Hive (TV story), without access to the TARDIS - The Time of the Doctor (TV story), or, simply when already weakened and frail with age (also The Time of the Doctor) leads to a visible ageing process which is beyond the control of normal Time Lord biological defences, whereas, when it comes to simply the passing of time, a normal, healthy Time Lord with a nearby TARDIS connected by symbiotic link (see The Deadly Assassin (TV story) and its reference to Artron energy) is easily biologically capable of keeping that in check. Thus, for instance, Time Lords are clearly not overly concerned by regenerating into bodies whose physical appearance suggests an already significantly advanced ageing process - the Doctor in Spearhead from Space (TV story) may bemoan his hair, but he doesn't complain that his newest life looks to be already middle aged at best, for instance, because, barring accidents, his third incarnation could have easily the same life expectancy as his thirteenth.
 * In turn, then, when we consider multi-Doctor stories, Time Crash (TV story) establishes that the time differential effect which comes into play here is one of these phenomena of time which artificially ages a Time Lord, but, like the tachyonic ageing effect in The Leisure Hive (TV story) is temporary, and will reset when the stimulus is removed or undone. Why, then, does the Hurndall Doctor so radically fail to resemble Hartnell at all? Well, perhaps because this incarnation died of old age forced on him by an outside influence - The Tenth Planet (TV story).  This incarnation was already old and frail enough that such things were fatal once- pulled out of time and subjected to centuries worth of artificially inflicted time passing, according to Time Crash (TV story) and its theory, the original Doctor is only able to survive at all through being in what is, essentially, a paradoxical partially regenerated state. He can't regenerate, as that would well and truly fracture the timeline, given that he's currently embroiled in an adventure with his actual next incarnation, so instead, as in Twice Upon a Time (TV story), he endures in a sort of halfway-house state, marinading in regeneration energy, his face "all over the place".


 * It's also possible that they're not the same incarnation, to begin with. The Hurndall Doctor identifies himself as "the original", and recognises Susan on sight. Who knows where he was abducted from, except that the sky resembles that of the Death Zone, and he appears rather wiser to Rassilon's ways than the second, third,and fifth Doctors. Perhaps this is the first incarnation of his life-cycle as the other (Lungbarrow (novel)), who subsequently went on to fake his death, deliberately fade into the background for his next eight incarnations through Time Lord history The Brain of Morbius (TV story) before finally, in a tenth incarnation that somewhat resembles his first, stealing the antiquated TARDIS he built so long ago, rescuing his granddaughter from the ancient past, and erasing himself from Time Lord history - inadvertently erasing much of his own memory into the bargain. The Watcher in Logopolis (TV story) is thus so significant because its actually the end of his first regenerative cycle and a last-minute top-up as per The Time of the Doctor.


 * The mini-episode Time Crash (TV story) explains that when two or more Doctors meet up, the earlier Doctor(s) will appear to have aged proportionately, and that when they are returned to their own place in the Doctor's time stream will revert to their proper appearance. Since this is a Fifth Doctor Adventure, set in the Fifth Doctor's present, and the earlier Doctors are all time-scooped from their own place in the Doctor's time stream, this effect will be seen on all of them, explaining the Second and Third Doctors' apparent ageing. It doesn't really provide an in-story explanation for Hurndall though, unless we accept that Hurndall is an aged Hartnell (Hartnell was in his late 50's when he left in 1966, Hurndall in his 70's for The Five Doctors).
 * This is not apparent with the War Doctor in The Day of the Doctor though? Yes, he's already old in appearance but he hasn't aged even more like he should have due to his meeting with future Doctors whereas the Tenth Doctor has physically aged due to this.
 * Given it's the War Doctor present since its him using the Moment to contact his future selves, you'd expect Tennant and Smith to de-age to some extent to match him. Not too much of a problem though since Tennant and Smith didn't look that much older, at least compared to the actors in the Five Doctors.
 * Furthermore, "Time Crash" seems to suggest that the time differential "shortening" effect is worse the longer the time "gap" that exists the incarnations that are meeting (that is, the Fifth Doctor doesn't just look older but looks particularly older because he is meeting a self who is several centuries in his future). Essentially, in this case Doctors One-Three look older because there is a lengthy gap between themselves and the Fifth Doctor, and the differential is aging them "up" to compensate. If the Fourth Doctor had also been present, then in-story this effect might not have been as severe (though, of course, in reality the actors would have aged the same regardless, but just go with it).


 * After being frozen by Borusa, the Brigadier clearly moves his head to watch Borusa go.
 * The Brigadier has had training to resist such mental attacks see PROSE: No Future.
 * They're not physically frozen by Borusa, just being mentally controlled by him. Slight movements aren't unreasonable.


 * The Cybermen following the Master into the Tomb do not react at seeing the Doctor.
 * They do see him (one or two even watch as he and Tegan run off), they just aren't concerned with him at this point.


 * The Master's first crossing of the chessboard is in a perfectly straight line, with a brief pause in the centre. Where is his application of Pi supposed to come in?
 * It's possible the sequence only runs in one dimension.
 * Pi can certainly be used to calculate a straight line, and since we don't know what calculation the Master and the Doctor used it for, we can't really dispute the result.


 * If the Time Lords can offer the Master a new life, then why is Borusa so worried about his own mortality?
 * Just because they can offer a Time Lord a new cycle of regenerations doesn't mean it's not exceptional to do so. There's no reason for the High Council to grant Borusa more regenerations. Besides, Borusa is not after more regenerations, which after all, can go wrong, and do not protect one from devastating injury, but true immortality.
 * Borusa could have very easily lied about his capability to grant new regenerations.
 * The Master is inhabiting the body of non-Time-Lord Tremas at this point - presumably the offer is to turn this body into a regenerating Time Lord; it's not until many years later that we see Time Lords handing out new regenerations to the Doctor, and that was only at the very end of his final life - perhaps Borusa would have had to wait around until he was nearly dead of old age and hope that other Time Lords were around to grant him a new cycle at that point?


 * The Master meets the Fifth Doctor on his way to the Tomb, then offers to lead the Cybermen to the Tomb. He is then beaten to the Tower by the First Doctor, who only started his journey when Susan and Tegan arrive back. They were delayed chasing the Third Doctor.
 * The Master is stalling for time, trying to come up with a plan to get the upper hand over his captors.


 * Like in Earthshock a Cyberman uses the phrase 'Excellent' when they are said to have no emotions. Maybe the Cyberleader has a limited sense of emotion.
 * Or the phrase might simply be a stock phrase the Cyberman has been programmed to say, but is otherwise as meaningless as "Have a nice day". The word "excellent" doesn't necessarily convey emotion, simply that something that occurred is in line with their purposes.


 * How could the Brigadier say "Nice to see you again!" to the Master after the latter has just regenerated and so the Brigadier wouldn't recognise him at all?
 * He figures it out like the Third Doctor did. The two incarnations of the Master don't really look that different. Also there is nothing to indicate the Brigadier hadn't met the Master in his current form at some earlier time. Additionally, unlike the Doctor, who changes outfits with each regeneration, the Master is still wearing a basic black outfit.
 * Consider also that the Brigadier is, essentially, encountering a sinister bearded man dressed in black holding the Doctor at TCE-point sneering about how he's been looking for an opportunity to kill the Doctor for a while. Given that this description fits many of his previous encounters with the Master down to the letter, it is hardly an entirely unreasonable leap for him to make.


 * No reference is made to the Doctor's newest companion, Kamelion, who only joined in the preceding serial; even the android's former owner, the Master, makes no reference to him.
 * PROSE: The Crystal Bucephalus accounts for why he does not feature. As for the Master it is not clear where in the Master's personal timeline he is taken from, nor would the Master be particularly interested in Kamelion given the circumstances.


 * How can the Second Doctor know that the Time Lords sent Jamie and Zoe back to their own times and wiped their memories of him when he regenerated at the end of the War Games? It is clearly Jamie's recognition of the Brigadier that tips the Doctor off, since Zoe does not mention the Brigadier by name during the scene.
 * See Season 6B, a theory created by fans and later supported by Terrance Dicks in his Past Doctor Adventures novel Players, that suggests the regeneration did not occur immediately after the end of The War Games and that the Doctor went on to have several adventures working for the Celestial Intervention Agency before finally regenerating. This theory is also intended to cover discrepancies surrounding The Two Doctors.' Even without Season 6B, it's clear from prior dialogue that the Second Doctor remembers the events of The Three Doctors, leaving open the possibility that the fate of Zoe and Jamie was communicated to him by his future self.
 * The Second Doctor has been hiking across the Death Zone with a version of the Brigadier who knew both the Third and Fourth Doctors. It is possible that the Brigadier found out what happened to Jamie and Zoe from the Third or Fourth Doctors and then informed the Second of it at some point when they were walking.
 * To say nothing of the fact that he doesn't know their fate. He says "the Time Lords erased all your memories of me", or something very similar. However in The War Games, the Time Lord explicitly tells him that they will remember their first adventure with him (The Highlanders and The Wheel in Space) but not travelling with him. Would the Second Doctor really not remember that difference? Interestingly, in The War Games, the Second Doctor assumes that Jamie and Zoe will lose all memory of him too, before the Time Lord corrects him! As stated by someone else, in The Three Doctors, the Second Doctor sees his own future. The Third Doctor is exiled to Earth, without a working TARDIS, He is working with the Brigadier and Benton, who are not much older than they were in The Invasion. His memory has been significantly wiped. He is made to carry out missions for the Time Lords (further removing a need for Season 6B). He already has a new BFF (Jo). And there is no sign of Jamie or Zoe. No one even mentions either of them in passing. So, what would the Second Doctor think had happened? And, as noted, at the start of The Five Doctors he still remembers the events of The Three Doctors? And again, crucially, his comments about Jamie and Zoe are not what happened in The War Games. It is what the Second Doctor thinks happened to them, not an actual memory.
 * He could have simply been removed from his time stream moments before regeneration, after having witnessed Zoe and Jamie being wiped of their memories.
 * From The Five Doctors:

SECOND DOCTOR: You're not real. When you were returned to your own people, the Time Lords erased your memory of the period you spent with me. So how do you know who we are? Answer! However, in The War Games: DOCTOR: They'll forget me, won't they? TIME LORD : Not entirely. They will be returned to a time just before they went away with you. They will remember their first adventure with you, but nothing more. and (The Doctor watches on the trial chamber viewscreen as a confused Zoe walks down a corridor.) TANYA: Oh, Zoe. Zoe, are you all right? ZOE: Oh, yes. TANYA: Are the Doctor and Jamie gone? ZOE: Yes, I've just seen them off. So, Zoe does remember the Doctor and Jamie (and considering the events of The Wheel in Space, is certain to remember them for the rest of her life. And the Doctor watches this discussion on the monitor. And the Time Lord tells him they will remember him. So clearly the Second Doctor in The Five Doctors can not be a Second Doctor from after The War Games. It has to be one from before The War Games, who is making an educated (but incorrect) guess about his future.
 * The time lords could have granted him a last request to visit the Brigadier.
 * I'm a little amazed people analyse the Second Doctor's interactions with his companions so much when its made very clear that the third Doctor is taken from a time before he met Sarah Jane yet still remembers her. Explicitly clear in fact to the extent that its clearly intentional that some kind of memory meld or precognition within their own incarnation is going on. He's even fully aware what his forth incarnation is going to look like.
 * IF Jamie and Zoe were returned to their timestreams with only their memories of their first meeting with the Doctor, then they would no longer retain the deep affection they developed for him over their lengthy travels together; they would only remember that first meeting with him, and thus on meeting him again they would only react to him as a near-stranger that they met once, not as an old and close friend they instinctively trust to protect them from harm. It is how familiar and close they are acting towards him that is suspicious.


 * How does the Doctor know the Time Scoop didn't kidnap Jamie and Zoe from a time when they were still travelling with the Doctor?
 * Because he can see they have aged since then.


 * Susan recognises the Cybermen when she sees them outside the TARDIS, yet she stopped travelling with the Doctor long before his first encounter with them.
 * She sees them in this adventure when she is with Tegan who names them so she knows what they are called from there. She may also have become aware of the Cybermen while living on Earth in the 22nd century, from historical records of events such as the Battle of Canary Wharf and other Cybermen incursions on Earth that may have become public knowledge by then.
 * Some off-screen stories have indicated the First Doctor and Susan had met the Cybermen before.


 * The First Doctor and Susan stop to rest in the Death Zone. Susan then points out the TARDIS with surprise and delight, though it is in an open space not ten metres before them
 * Perception filter at work? Or, they were tired from walking and just hadn't noticed it there.
 * The camera angle is poor, but its inferred that its around the corner!


 * If Borusa can use the time scoop to bring the Doctors into the Death Zone, could he not use it to take the Daleks, Cybermen, Yeti and Raston Warrior Robot out?
 * He most likely took out most of the obstacles but no one can make it perfect. Plus there is no reason to think just because he can put them in, he can take them out. After all, a parachute only works one way. It is also possible, as implied by his becoming the baddie, that his most recent regeneration has left him mentally unbalanced, and so he is perversely amused at the idea of leaving enemies in the zone for the Doctor to face. As he remarks after being unmasked, slightly derangedly, 'It's a game... within a game'.
 * This is pretty clearly covered when Borusa tells the Doctor he intentionally gave him enemies to face as well as companions to help him, as 'a game... within a game'
 * Mad as a spoon though he certainly is by this point in time, it may well be the case that if Borusa had purged the entire Death Zone of enemies then one if not all of the Doctors would have quickly realised that something even more downright suspicious was going on than a simple attempt on their lives.


 * If the transmat can take Borusa, the Fifth Doctor, Chancellor Flavia and her guards directly to the Tomb of Rassilon, why the elaborate plan to use the Doctors to find it?
 * The transmat could only take people to the tower after the force field was lowered, as was explained.


 * Despite the few, somewhat tame obstacles the Doctors encounter, they make their progress to the Tower with relative ease.
 * Borusa most likely took most of them out. Plus many could have died off.
 * Borusa wanted it to be a game, but he also wanted the Doctor to win.
 * The Doctor is a hardened adventurer and covert agent, accustomed to both physical danger (such as the monsters in the Zone) and mental attacks (such as the "phantoms" and the pervasive psychic oppression of the tower). Borusa did not choose him (five times over) at random... Had Borusa - who has presumably spent most if not all of his life in the comforts of the Capitol - attempted the quest in person, it is doubtful he would have fared so well. One need only remember how quickly Rodan fell to pieces on her first experience of the Gallifreyan great outdoors ("The Invasion of Time").


 * What is the structure the First Doctor and Susan encounter the Dalek in? Aside from the Tower, no other structures are seen throughout the whole of the death zone.
 * That doesn't mean there aren't any. It could be the remains of a downed Dalek scout ship, dumped in the zone by Borusa. Susan does suggest that they are on Skaro.
 * However, the Daleks wouldn't likely build a corridor that reflects their own lasers in their own ship. One of the other competitors in the Death Zone in the past may have built it, or there may be several caverns like it all across the Zone. Doctor Who Magazine referred to it as the Mirror Chamber.


 * When each of the Doctors are taken out of the Doctor's time stream, only the Fifth Doctor is affected. Why aren't the Second, Third and Fourth getting the same reaction when the First Doctor is taken out and so forth?
 * They probably had the same reaction but it was not shown on screen or perhaps the previous Doctors were taken out of time at the same instance. Or perhaps only the Fifth Doctor felt the effects as he was at the time the "current" Doctor. Further, it's doubtful the other Doctors felt the effects as, like the Fifth, the other Doctors were among witnesses who would have asked the Doctor if he was alright when he yelled in agony (the Second Doctor was standing in front of the UNIT receptionist and the Fourth, putting aside the fact that he was in an insert from Shada was punting with Romana) or, in the case of the Third Doctor he was driving, and had he been affected, when we first saw him he wouldn't have been so pleasantly enjoying a drive in Bessie (in fact he'd be lucky if it didn't make him crash).
 * The effect only reached the Doctor in his "current" form relative to when the events were occurring.
 * In a "linear" sense, the previous Doctors are presumably being snatched out of time too quickly for the effects of having the selves before them being snatched to reach them. As the Fifth Doctor wasn't being snatched out of time, however, he was able to experience the full effects of it occurring.


 * Why doesn't the Fifth Doctor remember the events already (likewise the Third, Second, etc.).
 * This is an issue faced by every multi-Doctor story and requires suspension of disbelief from the audience. It can be rationalised that the memories of the interaction were suppressed by the Time Lords, which is supported by dialogue in School Reunion suggesting Sarah Jane and the Tenth Doctor *may* have no memory of meeting during The Five Doctors, or Sarah Jane, did not know if the Fifth Doctor was an earlier incarnation and her's - the Fourth Doctor - was the most recent, or they may just chosen to have not mentioned it.
 * A further rationalisation is that the lack of memory is yet another effect of the 'time differential' that aged the Fifth Doctor when he met the Tenth Doctor. The Doctor's memories of previous encounters with his past selves may be distorted or incomplete due to the time differential shorting out. He may recall some details, but he does not have a complete memory of the event. Also note that in The Fires of Pompeii the Doctor tells Donna that there are some moments that are in flux, this is also mentioned in The Waters of Mars, the moments when the Doctors are taken out of time are these types of moments.
 * In The Day of the Doctor the Tenth Doctor comments that he will not remember the events. If past Doctors did remember these events, then it would create a paradox, and the universe would cancel out this paradox by forcing the Doctors to forget. Some Doctors may retain vague memories, such as the Second Doctor mentioning his meeting with Omega, but not specifying that he remembers meeting his other selves at this time.


 * The TARDIS is virtually indestructible. Why are Turlough and Susan so concerned about the ring of bombs the Cybermen have placed around the ship?
 * The key word here is 'virtually'. They may recognise the type of bombs being used as a kind that could harm the TARDIS. They both have personalities prone to worrying as well.
 * In addition, the TARDIS defenses may have been shut down when it was immobilised in the zone. As shown in TV Journey's End, the TARDIS is extremely vulnerable without its defences.


 * Who is controlling the Yeti and why?
 * Either it is working on some kind of default setting to destroy all humans it sees, or the Great Intelligence (being spread out over the astral plane) has been drawn to this lone, active one of its servants and is taking this chance it has to avenge itself on the Doctor and the Brigadier.
 * In The Name of the Doctor, it shows the Great Intelligence in one of the Time Scoop scenes and he could have purposely been abducted by it to kill the Doctor as he revealed at the climax of The Name of the Doctor of his plan to re-write the Doctor's entire history, turning all his victories into failures. He isn't shown on the board showing all the Time Scoop abductees because he doesn't exist fully as a physical form.
 * It could be Rassilon guiding them to the tower.


 * During Borusa'a initial unmasking and subsequent conversation with the Fifth Doctor, he holds the model of the Master from the board and says 'I gave you an enemy to face', as if taking credit for the Master's presence in the zone. However, he stated earlier in the story that the other members of the High Council insisting on involving the Master did 'not please' him.
 * The Doctor doesn't know that, and it allows Borusa to save face. Also, Borusa may have known the High Council's decision and even manipulated that decision. He then would have feigned disapproval in order to disguise his plan.
 * It's not uncommon for people, particularly a somewhat insane person, to rationalise to themselves and others that they had control over events which they truly did not.
 * Borusa was presumably pretending to disapprove of the plan to send the Master into the Death Zone because if he hadn't, people might wonder why he was so eager to send the Master into the Death Zone.


 * Susan's reunion with her grandfather doesn't seem to be as emotional as one would expect given the Doctor's reaction to her departure in The Dalek Invasion of Earth.
 * Almost immediately after they are reunited, they are running for their lives from a Dalek.
 * Also, although Terrance Dicks obviously didn't know this at the time he was writing The Five Doctors, in Susan's timeline (and the Master's) this has to come after Legacy of the Daleks, so she's already been reunited with him.
 * Leaving aside the fact that it adds the problem of Susan not reacting to the Master after seeing him murder her husband (Tegan identifies him so she must know who he is), the version of events given in Legacy of the Daleks actually increases the problem: Not only do Susan and the Doctor meet for mere seconds in that story and not speak to each other, but if you accept the book's claim that Susan ages far slower than human and still appeared a teenager at that point, this must take place centuries later from her viewpoint (and hasn't even happened for the Doctor).


 * Why doesn't Sarah Jane just find her own way up the slope she fell down? The slope isn't deep, you could walk up it.
 * She was in fog and disorientated after being taken to the Death Zone.
 * There were no suitable slopes on location. The camera angle used, was the best possible for such a tricky situation.


 * The statements that the ring grants you immortality contradicts the statement in The War Games, when the Second Doctor said that "we can live forever barring accidents".
 * He may not have been referring to the ring at the time; or may not have known of the ring, he may have only known of Rassilon.
 * The Doctor was presumably not speaking 100% literally at that time. Although not exactly "forever", Time Lords can live for an extremely long time through the regeneration process.


 * Susan, at this point is married to David and should have four children, Ian Campbell, Barbara Campbell, David Campbell Jr and Alex Campbell. Where are they? they would, presumably, seeing how affectionate Susan is the the 1st Doctor, still be young.
 * Susan, being the Doctor's granddaughter, is not stupid, and she is younger than the Doctor, her senses are probably better. If she felt, or heard, the Time Scoop coming, she would have presumably either a) hidden her children to keep them safe, b) asked David to keep them safe, or c) it's not late enough in her timeline for the children to be born, after all, Ian, David Jr and Barabara are adopted, because we do not know how old they were when they were adopted by David and Susan, they may have already been teenagers, and thus, may already be grown up and be married with children of their own, and Alex was born 17 years before David, Susan's husband died, so presumably, because David cannot have been older than 30 when he married Susan, and she, presumably as they adopted three children, was not old enough to have children, Alex was not born at the time of the Five Doctors, as Susan stated that she was 15 when she left the Doctor, and looks to be about 10 years older, possibly 15, when she was reunited with her grandfather, thus her husband was only about 40, or 45, at the latest, so still in the years able to have children, so Alex may not be born yet.
 * She only "should" have children if one believes certain stories in other media. It is not at all uncommon to find televised Doctor Who that contradicts a comic, novel, short story or audio adventure. Television production crews have never regarded themselves beholden to stories in other media — especially not in this case where the story in question was published after the production of The Five Doctors.
 * Actually, historically, Doctor Who TV stories don't contradict other media (or at least the novels, BFAs and later comics) that much more often than they contradict other TV stories. But the fact that in this case the TV story came first means that any discontinuities have to be charged to those later stories, not to this one.
 * Even *if* you accept that she has those children, they would presumably only have been taken by the Time Scoop if they happened to have been physically right next to her at the particular moment it came for her.
 * Indeed, Borusa probably quite deliberately chose a moment when she was alone to use the time scoop on her. He only took people he wanted to be in the game.
 * He was mad, but we saw that he wanted the Doctor to win the game and gave him specific companions to help him. Placing the children in the Death Zone would have slowed him down.
 * Really, the only contradiction in this question is the one that already exists between the novel Legacy of the Daleks and the BF audios about Susan. It's inconsistent that she has both Alex and the three adopted children, period. If she has Alex, that fits into The Five Doctors one way; if she has the other three, it fits another way, and neither one has any continuity problems.


 * The First Doctor fails to recognise the Master, despite them knowing each other since youth (plus the established ability of Time Lords to recognise each other); even though the Master has changed appearance, the Third Doctor recognises him instantly.
 * Since the Master is not in a Time Lord body, but the stolen body of Tremas, it's possible "Time-Lord recognition" doesn't work (which may explain why the Ainley version of the Master was able to disguise himself in other Davison-era stories) so the First Doctor doesn't recognise him as one of his kind.
 * The first time we see the Doctor and the Master meet out of order, other than multi-Doctor stories like this, is in Legacy of the Daleks, which makes it clear that the Doctor had never broken the rule (about Time Lords meeting out of order) before. So, if the 3rd Doctor and the Tremas Master ever met, the 8th Doctor must have forgotten about it.
 * Considering how similar the two incarnations look and act, it's possible that the 3rd Doctor mistakenly recognised the Ainley Master as the Delgado Master, and then a bit later realized that it was a different incarnation. However, it's unlikely that the Master had the same distinctive facial hair, dress sense, etc. in the Academy days.


 * It's explicitly stated that the Doctor doesn't exist 'in any of his regenarations'. Does this mean that the remaining 6+ Doctors were also taken to the Death Zone?
 * Doesn't matter if they were, seeing as it is most likely only the doctors before the Fifth that have their memories erased, they would all know what was happening and how it would end, so all they would have to do is simply avoid their past selves, which seeing as they would know where they were wouldn't be that difficult, til their predecessors won.
 * Time is relative. The Time Lords would not have necessarily looked beyond the version of the Doctor "current" relative to the events going on at that point.
 * While time travel naturally creates complexities, presumably the Doctor's encounters with Gallifrey and the Time Lords located there occur in a linear fashion -- that is, the Gallifrey we see in "The Five Doctors" exists at the exact same time as the Fifth Doctor. Ergo, they don't register any future Doctors because, at that point for both the Doctor and Gallifrey, there are no future Doctors; the Sixth, Seventh etc. Doctors don't exist at that point for either of them.


 * Sarah tells the Third Doctor that she "remembers" the Cybermen, and he fails to react to the comment in any way. Since he never fought the Cybermen with her, he should at least be mildly perturbed that she revealed a spoiler about his future.
 * Maybe, but he's got more pressing issues to worry about.
 * Also, the fact that the Doctor keeps encountering things like the Cybermen, the Daleks etc. presumably isn't that surprising to him any more.


 * If Borusa can get into Rasillon's tomb by teleport why does he need all the Doctor's incarnations to be there at all?
 * He needs somebody to get into the tomb the hard way so as to take down the force-field around it. Only then can he use the transmat.


 * The Fifth Doctor and the Brigadier both treat immortality with scepticism, despite having witnessed it first hand in Mawdryn Undead and Enlightenment.
 * Their disbelief is with the idea of successfully becoming immortal. The Eternals are naturally immortal, and Mawdryn became immortal in a disastrous way. That one might successfully achieve immortality would look even less likely.


 * How does the Third Doctor know what his next incarnation will look like when he says to Sarah Jane "teeth and curls" when she mentions that she saw him change into the fourth?
 * Sarah Jane makes hand movements/gestures, indicating first curly hair and then wild teeth, and only after that does the Third Doctor say the line about 'teeth and curls'.


 * At the end, The Third Doctor tells Sarah-Jane that it's nice to meet her, then says he will "explain later" (really helpful, that) if this story really is set after 3 has met Sarah already, how does this line make sense?
 * The way I interpret it is that he was referring to "meeting" her as the First Doctor in this story.


 * The Eleventh Doctor later claims that he took the Seal of Rassilon from the Master in the Death Zone (which is true); however, it is clearly seen that Sarah takes it from the Doctor and pockets it herself. Assuming they returned immediately following the events of this episode, when and why did she give it back to him? (This is alluded to in the production notes for the transmission version; Richard Molesworth suggests she kept it for herself.)