WMG / Doctor Who S30 E17/E18 "The End of Time"

Confirmed

The Time Lords are not dead, but they are trapped in a Pocket Universe as a consequence of the Time War

Contrary to the Doctor's belief, whatever ended the Time War did not kill the other Time Lords. It trapped most of them inside a parallel pocket Universe which they can't escape; the destruction/sealing off of Gallifrey made crossing universe boundaries difficult, and they were cut off from the power source for their TARDISes with no experience at jerry-rigging them. But they can still watch the main Universe and the Doctor.

Since the barriers are closed, they cannot interact with the rest of the Universe or inform the Doctor of their current status. Because they are not in connection with the universe the Doctor now lives in, he can't feel them anymore.

In an ironic twist, now that the Time Lords can't interfere in the affairs of the Universe, they wish to. Desperately.

• Status: Confirmed in Broad Strokes, Jossed in detail.
  • Fairly accurate description of Day of the Doctor and Time of the Doctor, though

The Time Lords were not wiped out in the Time War.

We know that at least one Time Lord survived the War by turning human and hiding. The Time War was supposed to have destroyed the Daleks together with the Time Lords, but every season the Daleks Keep. Coming. Back. What happened was, there was no Time War. The Time Lords got tired of The Doctor always attracting trouble, so they wipe his memory, force him to regenerate, and kick him out into the Universe all alone. Gallifrey and the Time Lords are still out there; it's just that The Doctor can't sense them anymore.

• A bit of an over-reaction, given that he only ever returned to Gallifrey when he was dragged there.
• Status: Existence of Time Lords confirmed, absence of Time War Jossed.

Donna will come back, possibly as a Time Lord.

She DID absorb all the Doctor's knowledge. While she got mind-wiped, there's people saying constantly that she's 'special', and she even has quantum irregularities. The fortune-teller even says "What will you become", after all.

• She didn't really get wiped—that is, the knowledge wasn't deleted. She was made unable to access it, but it's still there. Otherwise there would be no danger of her seeing aliens and suddenly remembering it all. This makes nonsense out of the idea that it's too dangerous because her brain can't hold it—she doesn't remember it, but it's still there, still being held.
• It's also ridiculously unlikely, in the Doctor Who world, for her never to see anything which reminds her of the Doctor and jogs her memory. This world gets invaded by aliens every year. She's not always going to miss the headlines.
• If Donna comes back as a Time Lady, then we should get to meet "Donna Noble II".
• Status: Confirmed in Broad Strokes.

The Time Lords will return during the last special

Roger Bailey and Timothy Dalton both are credited as "Time Lord" in The Waters of Mars and The End of Time. And Timothy Dalton was seen on set wearing what appear to be Time Lord robes.

• Status: Confirmed. Timothy Dalton is the Narrator.

The person who will knock is Donna's grandfather.

The Doctor knows he's doomed. Four knocks, then he's dead.

After "Waters," he returns to Earth - one last trip, to say goodbye. It's been good to him, so one last time - maybe before he goes to crack open the Time War and save the Time Lords - something that he knows will kill him, or drive him mad, but he's doomed anyway, right?

And he says goodbye to Earth, and starts the TARDIS.

And stops, because someone's knocking. One. Two. Three. Four.

And he knows he has to stay now. He goes to the door.

"Something's wrong with Donna."

Cue opening credits.

• This is based largely on the new teaser from the end of Waters. When the Doctor has his discussion with Bernard Cribbins, he says "She said 'He will knock four times,'" followed by a "I'm going to die." I'm sure those are out of context, but it sounds like the Doctor explaining how he knows that he hasn't got long - the knocking has already happened.
• Status: Confirmed in Broad Strokes. Jossed in detail.

The twin nuclear vaults are a Chekhov's Gun.

Best guess: The building's gonna blow up, and due to the way it's set up, one person needs to be trapped inside.

• Perhaps one of those spiky green aliens which I've forgot the proper name for?
  • Status: Confirmed in Broad Strokes. Jossed in detail. Wilf gets inside one of them to let another man out. Then the Doctor lets himself in to let Wilf out, absorbs all of the radiation and that causes him to regenerate.

The Time Lords in 'The End Of Time' are Lawful Evil.

Judging by the way the Time Lord President calls 'the end of time itself' their victory, it seems to be hinting that they are falling in line with the likes of necromancers/Necrons; that they believe the only way to keep time and dimensions in order is to destroy it utterly...

• Well, they're all wearing Prydonian colors, and the Prydonian chapter was sort of the Slytherin House of Time Lord society...
  • The Doctor's Prydonian, I think Romana was, and Borusa was fine until he went insane. Try again.
• Word of God (Russell T Davies) confirms this. He said "I've always known the Time Lords were evil."

Jossed

The "it" "returning through the dark" referenced in "Planet of the Dead" is the Master

He will apparently "knock four times". Go on, tap out the rhythm of the "drums" from Utopia/The Sound of Drums/Last of the Time Lords.

<waits>

See, it's four beats! Ergo, more Master.

Also, the Simm!Master is in the trailer for the last 2 specials. BOO YEAH!.

• Status: Jossed.

The man who will 'knock four times' is the Master.

• ...Tap Tap Tap Tap.
• ...Tap Tap Tap Tap.
• ...Tap Tap Tap Tap.
• ...Here come the drums...

  • I was right! Trailers for 'the end of time' (Specials three and four) prominently display John Simm as the master.
  • And it's been officially confirmed by the BBC that John Simm is playing the resurrected Master and Lucy Saxon will be returning with him (So she's probably the one who picked up his ring which seemed to contain his "Essence"

  • That's twelve.
  • Let's be honest. If their going to kill the Tenth Doctor off, he has to go out facing either the Daleks or the Master. They're the only two adversaries worthy of killing him off. And given that John Simm has actually been sighted on set, it's more or less a fact by this point that it'll be the Master. (Of course he might be teamed up WITH the Daleks. Wouldn't be the first time he worked with them)
• "The Waters of Mars" is an anagram of "Wars of the Master"...
• The Sun said it. It must be true.
  • Actually, that particular paper has been very accurate at times...
• How about the Midnight entity? It started off knocking twice- then when the husband knocked three times, it replied with three knocks. The doctor knocked four times. . . and it knocked four times back. Remember, this thing is able to Mind Rape the Doctor with contemptuous ease, and Sky specificially referred to it as male during her big villain speech. "He's waited so long, in the dark, and the cold, and the diamonds, until you came. Bodies so hot with blood and pain. . ."
• Status: Jossed. It's Wilf.

No, the man who will 'knock four times' is...

• It's quite possible Davis may want to bring back one last old face that has yet to be used to close out the 10th doctor. So, based on that, tropers, start your guessing...
  • The knocking man is Fenric!
  • The knocking man is Omega!
  • The knocking man is the Valeyard!
  • The knocking man is Other-Ten as the Valeyard as theorized above!
  • The knocking man is a Time Lord! (This time, this might actually be accurate in some way)
  • The knocking man is a Tommyknocker!
  • The knocking man is The Trickster!
  • The knocking man is Bilis Manger!
  • The knocking man is Sutekh!
  • The knocking man is The Celestial Toymaker!
  • The knocking man is The Beast!
  • The knocking man is Lucas Finch!
  • The knocking man is the Black Guardian!
  • The knocking man is Rassilon!
  • The knocking man is a Raston Warrior Robot!
  • The knocking... entity is Fate!.. What?
  • The knocking man is The Meddling Monk! ...what? He's been rumored to soon be played by Patrick Stewart (of Star Trek fame), the Meddling Monk is another Time Lord we've not seen since 1966 or so... come on, it's perfect. That is, if it's not the Master again.
  • The knocking man is the Watcher!
  • The knocking man is right behind you....
• Status: Jossed (see the above theory).
  • ...Well, that one sure played us for fools, didn't it?

The knocking four times thing refers to the creature from Midnight

Go re-watch the episode. When the Doctor knocked to get it to answer, it knocked four times.

• "What is it with humans and busses?"
  • The musical cues are exactly the same. Mind you, Murray Gold nicked some of his Midnight score for Davros. Hrm.
    • OK it is near confirmed at this point. First Carmen's prophecy in Planet of the Dead "It is returning from the dark" and now the Ood, "Because a shadow is falling over Creation. Something vast is stirring in the dark. And the darkness heralds only one thing, The End of Time Itself!" If that's not the creature or the master This troper will dance out my praise for RTD. Well should I dance the Humiliation Conga or the I fail dance?
• Status: Jossed (see two theories above)

The man knocking four times will be the Trickster, who will be responsible for the return of Gallifrey

During the Time War, there was a point where it seemed as if the Daleks were unstoppable. At this point, a Time Lord (probably not the Doctor or the Master) was approached by the Trickster, who offered to even the playing field in exchange for something in return. Accepting this offer, the Time Lord's decision caused the Time War to enter into a stalemate wherein the only means of ending the conflict was if both sides were destroyed simultaniously, something that the Doctor went on to cause.

Of course, the Trickster would have no interest in a universe inhabited entirely by Daleks, since it would be a realm of absolute order with no chaos whatsoever for him to consume. However, the removal of the Time Lords and the Daleks from creation ensures that the timespace continuum is far more unstable than it was before, a fact pointed out by the Doctor on many occasions, making it better suited for the Trickster's needs.

This will culminate in a situation wherein the Trickster is poised to create devistation on a cosmic scale and the way of stopping him will be if his deal with the Time Lord back on Gallifrey was unravelled, resulting in the Time War's conclusion being erased from history. Of course, this would have to mean that the Time Lord that did the deal in the first place would have to either have come back from the dead or never died in the first place, since the only way that the Trickster's deals can be undone is if the person who agreed to them revokes their consent (ala Andrea Yates). If the deal wasn't carried out by either the Doctor or the Master, likely candidates include Romana or Omega. In the latter case, the Trickster may have led Omega to believe that he could be released from the antimatter universe in the process somehow.

Alternatively, if the Doctor himself made the deal and simply forgot about it as Andrea Yates had forgotten hers, it could be that the deal was made in a timeline in which the Time War was decisively won by the Dalek side, wherein he'd been kept alive by Davros as a plaything. It could even be that the Valeyard is from this alternate timeline, the result of torment over untold eons at Davros' hands. When the Trickster came to offer either the Doctor or the Valeyard a means of changing the outcome of the Time War, the Valeyard's presence at the Sixth Doctor's trial could be all part of the deal. If this is true, then it would mean that when the deal was revoked, the Doctor would have to somehow Take a Third Option and ensure that the Time War ended in such a way that it resulted in neither the Trickster's altered timeline or the original outcome wherein the Daleks win. A Paradox Machine may be involved.

In any case, this would mean that "It is returning through the dark" refers to Gallifrey.

• Status: The Trickster: Jossed. Gallifrey returning: Confirmed.

Karen Gillan will be playing... Donna Noble.

Catherine Tate is confirmed as appearing in the last few 10th Doctor episodes. It's hard to imagine her having a part in whatever the events will be without remembering the Doctor, which has been established as fatal. BUT if the metacrisis mixed her with the Doctor enough, perhaps she has the ability to regenerate. Enter Miss Gillan as the 2nd Donna.

• Nice idea, but not true apparently. Karen will be playing a character named Amy Pond.
  • But what's to say that something doesn't happen causing her to lose all her memories, the metacrisis *and* regress to being a child or even a baby? True, she would no longer really be Donna but it'd still be a better outcome then Her Head Asplode or having her memory erased for a second time.
    • Status: Jossed. Donna is still mind-wiped at the end of 'The End Of Time', but alive (and so is her grandfather, surprisingly), and has somewhat of a happy ending.

Doctor-Donna is coming back

The Doctor only told Donna's family not to tell her about her journey. Another character (such as Martha, Jack, etc.) could contact her when another alien invasion kicks off, causing her memories to reappear, and for her to become Doctor-Donna again. Sure, they'll need to think of a way to fix the 'burning up' problem, but the Doctor Who writing staff are great at Ass Pulls like this.

• This seems pretty likely, as the whole 'burning up' problem was due to the Time Lord stuff still being stuck somewhere in Donna's head. Rather than getting rid of the information, the Doctor just wiped her memory. If the writers managed to Ass Pull Rose back from a theoretically inaccessible parallel world, they can figure out a way to bring back Donna and her Moment of Awesome.
• Another avenue for her return would be that enormous ring she was sporting in the last few episodes, which surely is a nod to the route left open for the Master. Well, that or it was a massive red herring/a really strange choice on the part of the costume department.
  • Word of God has it that the stinger was there to let future writers/producers justify the return of either Master or Rani, but nothing was certain by the airing date.
    • However Russell T Davies is Lying Liar Who Lies.
• Well, the problem was her conscious mind couldn't handle the sheer vastness of knowledge being a timelord imposed, in computer terms, a lack of RAM. Human minds themselves have the capacity to remember far longer than any single lifetime. The information is still in Donna's brain, just locked away. Finally, when we sleep, our brains organise the memories floating about into long-term storage. Basically, what I'm saying is that after some time (months or even years) Donna's mind will finish storing away all the timelord knowledge, which will then allow her to regain her memories without the mental burn-up, as instead of having the whole of history etc all at once, she'll just recollect the memories she's using at the time, like how a mechanic can know everything about how to fix stuff without having it on his/her mind constantly.
• So we have 3 possibilities; Donna regenerates (presumably upgrading her mind such that it can handle the influx), Donna adapts (possibly at some cost, time or otherwise), or something really complicated involving the Master, who may or may not be living in a ring that may or may not have something to do with Donna's. An ass-pull out of nowhere is also possible, but hardly counts as a theory.
  • Donna can't regenerate. She only got the Doctor's knowledge, not his physiology.
  • Or so the Doctor says, but what happened to Donna has no precedent in the entire history of the universe, and he didn't seem to double check his assumptions. There's plenty of room for him to be mistaken, just as he was about Jenny not regenerating. There's room enough for future writers to bring Donna back any way they like, and still point to something in the fourth series as 'evidence' that was always the plan.
  • Director's Commentary "josses" this. A scene where Donna hears the Tardis right at the end was cut precisely because it cast too much doubt on Donna being on a bus for good. If she comes back, it won't be because of anything that's been shown in the series, but only via the First Law of Resurrection.
    • Wilf's back in the 2009 Christmas Special. And RTD has as good as said that that means Donna's back, and they'd planned this from the beginning. (Which is presumably why they were so worried about leaving clues.)
• Status: Jossed. Donna comes back, Doctor-Donna doesn't.

The Drums are coming for the Doctor

Since the Master's death they've been looking for a new host, and as the last Time Lord approaches a regeneration they've found their chance.

• When the Master looked into the Vortex as a child, he saw something that drove him crazy, that stayed in his mind as the maddening sound of drums for the rest of his life.
• Whatever that something is, it is now coming for the Doctor - "returning through the dark".
• It will take a form resembling the Master's last regeneration, and when it arrives it will knock out the four-beat pattern of the drums.
  • It's been revealed that John Simm is playing the Master, not something impersonating him and Lucy Saxon is to play a part in his resurrection. That said "The Drums" may well be finally explained.
• It will act like a malign version of the Watcher, trying to manipulate the Doctor into regenerating into a destructive personality like the Master's, perhaps by playing on the Doctor's painful memories.
• Correct me if I'm wrong, but...when the Master asked the Doctor if he heard the drumming, did the Doctor ever say he didn't?
  • Yes, but the Doctor is perfectly capable of lying, and there was a hint of a pause first...
    • Well, I'll wear that. I just (as in, half an hour ago) gained this distinct feeling that he's going to start hearing the Drums, or at least announce that he can, before The Waters of Mars is over. It's based on the tenth teaser on this list, the fact that the prophecy thing isn't, "You're gonna die," but, "Your song is ending," and my theory that the Drums drown out any sense of morality a Time Lord has blah blah blah Valeyard.^note While I'm sick of these Valeyard theories, I can't stop thinking up more and more of them. It's almost like there's a 50th anniversary coming up or something.
• The something the drums are is either related to, or the whatever-it-was out of Midnight. It was in the 'cold' and the 'dark', which are recurring themes that pop up, and one place they appeared was in Sound of Drums/Last of the Timelords (the episodes he's reintroduced in)- the Toclafane said that was what they were fleeing. Oh, and in series 1 of Torchwood, the afterlife is described like that. So the Master died, and this... thing that gets into people's minds and drives them insane is coming from something like the afterlife? Hmm.

The knocking man is the Tenth Doctor

.Pounding desperately on the door of the TARDIS, with the Eleventh Doctor inside knowing he can't rescue him. Just because Word of God says that nobody has guessed it yet, and it's a tear-jerker.

• Wow! That would be heart wrenching. And cruel. And incredibly cool!
• Status: Jossed (see above).
  • You'll pardon me for being exceptionally relieved. I think we've had enough tearjerking for a while...

He will knock four times.

Deposing Harriet Jones. Saving citizens of Pompeii. Saving some of the Mars crew. The Tenth Doctor has knocked time's fixed points off-course three times. When he knocks a fourth time it'll all be over for him.

• Status: Jossed.

The Doctor will attempt to prevent the Time War, or at least save the Time Lords.

This is where he is headed when he activates the TARDIS at the end of The Waters of Mars:

"Have I gone too far?".

"No."

The Doctor realises that he needs one final act so that the laws of time are no longer at the mercy of the "Time Lord Victorious", even if it means dying in the process. This will be the "fourth time" mentioned above.

• Status: Jossed.

The Master's plan in "The End of Time" will involve some variant of The Doctor's "Tinkerbell Jesus" trick from "The Last of the Time Lords"

• The trailers show him firing energy blasts at The Doctor, an ability he's never had before. He is also shown covered in a blue, glowing light, much like The Doctor in "The Last of the Time Lords". There's no reference to the Archangel network being dissmantled following The Master's defeat, so it's entirely possible that the Master could use the same tactic (interfacing with the Archangel network to temporarily boost his telepathic abilities to omnipotent levels) for more malevolent ends.
• Status: Jossed.

The Master will have an Oh, Crap! moment once he realizes...

Everyone else is as power hungry as he is.

• This was This Troper's first thought. The Master is not a team player.
• Status: Jossed.

The drums are the Matrix, containing imprints of the Time Lords

Put into the Master's head when he was resurrected and made to believe they had always been there. The Time Lords knew he would run to save himself and keep the Time Lords' imprints safe, making him not the perfect weapon so much as the perfect safeplace for their 'essence', as it were.

And now they're back and ready to use it... maybe a council of them hid themselves; maybe they're coming from the past before Gallifrey was even destroyed (wibbly wobbly...). Either way, they're who is calling to the Master.

Speaking of which, he will knock four times. If this means signalling the return of the Time Lords, think about it. Who might want the Doctor dead out of revenge? They've killed him once before...

• Strongly supported by the next episode's opening scene—the Time Lord High Council was aware of the Doctor's plan to destroy them all, and the Lord President really did not want to die.
• Status: Jossed. Mostly.

Timothy Dalton's "Narrator" is the Valeyard.

• Status: Jossed. It was Rassilon.

The Master's device made it okay for Donna to remember everything.

Donna can't hold the Doctor's memories in her head, because she's half human, half-Time Lord. She's not entirely human, so the device doesn't actually turn her into the Master, but it does make her human half into a Time Lord; as a full Time Lord, she can remember everything that happened without suffering from Exploding Head Syndrome.

• Or she nicked River's TARDIS Diary so that she could write down her Time Lord knowledge, safely forget it, and then refer back to it if need be. (Exploding Head Syndrome is an occasional side effect, but she can get over it through interpersonal support).
  • Jossed. Donna's brain only went into meltdown AFTER the Immortality Gate was implemented. It's still very clear that without that safety measure, she would have died.

The Master needed a Stable Time Loop to pull off his resurrection, and the Doctor will disrupt it.

Lucy was never brainwashed, so if she says the Ancient Books of Saxon exist, they actually exist. Meaning the Master wull havenen traveled to Earth's past to start a cult worshipping him. The Doctor goes out of his way to explain to Wilf that he has to follow the Master's timeline, so he he can't prevent his resurrection. But there's nothing to stop him from stopping the Master from creating the cult that resurrected him, thereby reset-buttoning the poor guy again and foiling the Time Lords to boot.

• Jossed. And it was the Sacred Books of Saxon.

---

This episode happens immediately after "Day of the Doctor"

By the time of "The Wedding of River Song", he's forgotten about marrying Elizabeth I, something he clearly remembers having done when talking to Ood Sigma. Given that crossing his own timeline always causes him to forget everything until the final time he's experienced an event, the only way it makes sense that he'd remember anything that happened along the way is if it had just happened. Well, plus time to get an off-screen Expository Hairstyle Change.

• To be fair, he'd certainly remember proposing to Liz I regardless, because that happened before Eleven showed up.
• More likely, the 10th Doctor remembers a version of what happened with Liz, but won't remember the full thing till he experiences it again.

The Master inadvertently did humanity a whole lot of good in this episode.

The "Master Race" was generated using the same sort of body-altering medical reformatting as in "The Doctor Dances". While Rassilon undid the effect, there's no indication that he'd altered Time to do it; he didn't make it never have happened, he just undid the Master's template so everyone reverted to human. But when the nanogenes from the crashed Chula ship turned the victims of the gas-mask "plague" back to normal, they also repaired any injuries the victims had previously had, up to and including an amputee's missing leg. So if the Master did the same thing to every man, woman and child on the planet, it's entirely possible that Earth's entire population woke up in perfect health: the sick well, the injured healed, the disabled hale and hearty! How often do we see Nice Job Fixing It, Villain on a global scale?

The Doctor didn't take Elizabeth I's virginity.

As shown in "The Day of the Doctor", 10's memory would be spotty due to involvement with 11 and War. Not to mention that he was with her to try and solve the Zygon thing. The whole thing is a Not What It Looks Like scenario: the Doctor accidentally married Queen Elizabeth I, and the people who knew of this assumed he consummated the marriage. It didn't help the event took place at a time where numerous rumors(both at the time and historical) suggests she might have had sex(or even gotten secretly pregnant). The whole thing got out of hand, and Elizabeth blamed the Doctor for both leaving her and contributing to scandal still talked about by her namesake over 1700 years later. Even the Doctor considers he way have done the deed, since he can't remember.

The Time Lady who Wilfred repeatedly saw in "End of Time" was Oma Desala

Oh, come on! Opposes aliens that want to Ascend? Has a thing for a quirky doctor with glasses? (Not that kind of thing!) Appears when said doctor dies of radiation poisoning? It makes so much sense!

• Status Just for fun

The Time Lady who helps Wilf and the Doctor in "The End of Time" is...

Romana, as her final regeneration.

• Romana is definitely a possibility, but there's another likely candidate. Rewatch the scene where Wilfred asks the Doctor who she was. Instead of answering, the Doctor looks meaningfully at Donna, Wilfred's granddaughter. This troper believes that the Time Lady wasn't Romana, but the Doctor's granddaughter Susan.
  • Remember a Time Lady on the Council is killed by Rassilon? Considering the Kim Jong Il of Gallifrey is back to being President it wouldn't be surprising if he killed Romana.
• According to That Other Wiki, RTD intended for the Time Lady to be the Doctor's previously unseen mother. But her identity was intentionally left open ended so viewers could come to their own conclusion. So it could be any Time Lady, the Doctor's mother, Romana, Susan, Susan's mother, maybe even The Rani.
• Doesn't the ending of the second episode imply the Time Lady was Donna herself? As mentioned above, when Wilfred asks who the Time Lady was, the Doctor doesn't say anything but looks at Donna. Donna became a half Time Lord in the previous season's finale, and even though the Doctor erased the memory of all that from her head in order to save her, during "The End of Time" we see those memories may be coming back. So maybe Donna finds a way to access that part of the her brain without going insane, and eventually becomes a full Time Lord and moves to Gallifrey? That would also explain why the Time Lady seems to be so familiar with Wilfred, calling him "old soldier" and everything. It would also explain why she is so is so keen on trying to save Doctor number Ten from dying, even though she knows the Doctor can regenerate: Ten was always "her" doctor, so she has an emotional attachment to him, and doesn't want him to turn into someone else. Of course the Time Lady doesn't look like Donna, but that's what regenerations are for.
• The Time Lady could have been Clara,arguably even the same version of her that originally told The Doctor which TARDIS he should take.

The Time Lords created the Weeping Angels

In end of time part 2, Rassilon says " They will stand as monuments to their shame, like the Weeping Angels of old" so maybe Rassilon created the Weeping Angels to punish Time Lords, also anyone who has seen "The Five Doctors" special, where Borusa gets turned into a stone face and it's considered immortality would probably get what I'm talking about, maybe the stone face method was a prototype to the Weeping Angels being made.

The Time Lady Rassilon killed on the Council was Flavia.

She was Acting President once for the Doctor and seemed to be one of the more reasonable ones.

The scene with Martha and Mickey in "The End of Time, Part 2" was actually several years in the future.

It would at least explain why there was no mention of what happened to Martha's fiancé.

The Master deliberately allowed himself to be pulled back into the Time War

At the conclusion of The End of Time, the Master disappears along with Rassilon and his attendants as he is attacking them; it's implied that he got pulled back into the Time War with them.

He was, and it was on purpose.

What does the Master want most desperately at this point? To repair his dying body and/or regain the ability to regenerate. What is the one previously-established, sure-fire way in which a dying Time Lord may gain new regenerations? By using the Eye of Harmony. Which is on Gallifrey. The Doctor's TARDIS, and presumably by extension all TARDISes, used to contain a link to the Eye which powered it, but this surely isn't going to work anymore now that Gallifrey and the Eye have been destroyed.

So the only place and time that the Eye of Harmony still exists is on Gallifrey, inside the time lock. The Master has realized that the time lock doesn't apply to him due to the sound of drums paradox (indeed, the events of The End of Time hinge on that very point). So he must be calculating that, in the day or so of relative time left to Gallifrey within the Time War timeline, he will be able to gain access to the Eye of Harmony, heal himself or even regenerate, then escape under his own power.

As an added bonus, what's one of the Master's other established priorities? To get hold of a TARDIS. As long as he's on Gallifrey, why not steal one? He's done it before, he must figure he can do it again. And it's the perfect way to escape once he's done his business with the Eye.

That's the real reason he attacked Rassilon. Since when did the Master do anything truly altruistic?

• Confirmed in the Series 10 finale The Doctor Falls, when The Master tells the Doctor that the Time Lords fixed his condition, gave him a TARDIS and kicked him out before the Doctors saved Gallifrey.

Donna's wedding song was Don't You Forget About Me.

Because she forgot her best friend, she subconsciously picked that song, not sure why, her Time Lady brain trying to drop hints.

Some Time Lords escaped at the End of Time.

Gallifrey was back in the non-timelocked Universe. Not for long, but you can bet that some Time Lords like to live and jumped into their TARDISes (?) and ran. After all, they knew the Doctor survived, and on whom would you bet your money - the Doctor, or Rassillon? Thought so. The Survivors will rebuild a whole new Time Lord Society. It may be the only way to bring back the Master - or to explain the appearance of the Time Lady which Wilfried met. Timelock, remember?

The mystery Time Lord was the Master's father

Two people disagreed with the Lord President's plan in the end; the mystery Time Lady that was desperately trying to save the Doctor and a Time Lord whose face we never saw. This Time Lord was the Master's father. Upon learning that it was the President (and to an extent all of the other Time Lords and Ladies) who drove his son insane and was responsible for all the harm he caused, he joined forces with the mystery woman to try and stop the End of Time. Unfortunately, the Master was too preoccupied to notice him there.

• Jossed. According to the tie-in novel “The Missy Chronicles”, it was the Patriarch of the House of Steelhaven. For standing against Rassilon all of his family was murdered, except for one who was born with a defect that made her unable to regenerate.

The Master brainwashed himself to be obedient to the original should he ever be duplicated.

Because he's Crazy-Prepared, and it would probably be as easy as looking into a mirror and saying, "I am the Master! If you ever discover yourself to NOT be the original Master, you will obey me. If I'm dead, obey the oldest clone. In case of a tie, obey any obvious hierarchies dictated by circumstance, or simply form one randomly." This, obviously, resolves the question of how the Master Race managed to function as well as it did.

A few Masters survived Rassilon's device.

Either due to coincidentally being in remote areas, having prepared for this eventuality, or having died before the device activated and regenerated, de-linking them from the template. What's more, they don't remember Redemption Equals Death-ing, so they're just as mad as ever.

• Considering who you are speaking about, it doesn't count as guessing until you declare that The Master will be gone forever.

Rassilon was possessed or acting under the influence of the Black Guardian in The End of Time

If you assume that Claire Bloom's character was the White Guardian, then the Black Guardian is bound to be lurking around somewhere. Most likely, he (she/it) knew how desperate the Time Lords were and offered Rassilon a way to escape the time lock (which Rassilon then presented as his own plan to the unknowing High Council) in return for killing the Doctor (which was Turlough's initial goal in Mawdryn Undead while also being controlled by the Black Guardian). This would also fit in with the White Guardian's comments (the Black Guardian will be waiting for the third encounter) at then end of Enlightenment after the Doctor had defeated the Black Guardian for the second time.

• Alternately, the Black Guardian manipulated both the Daleks and the Time Lords. The Black Guardian probably hoped to use the ferocity of the Time Lord/Dalek war, and feed off of the psychic energies released during the conflict. The Black Guardian may have escalated the conflict by manipulating not only them, but possibly arranged the personal history of Davros, using him from the very beginning. The Black Guardian seems to be enough of a Chessmaster to pull off something like that.

Claire Bloom's character in "The End of Time" (a.k.a. the Church Lady, the Woman in White, the Woman on Wilf's TV, etc.) is...

• ...Romana.
  • Timothy Dalton's Time Lords appear to be a fairly sinister bunch. Given their history, though, it would make sense for there to be good ones as well, and what better choice to represent them than a regenerated Romana?
  • She opposed Rassilon's plan. The Doctor taught her well. Also, Rassilon probably overthrew her after she had him resurrected.
  • The EU maintains that she had become president of the council by the time of the beginning of the Time War, so she'd most likely have kept a seat on the senate even after being removed. Plenty of opportunity, and also lots of calls to bring her back.
    • There was also (I believe) mention of a "President Romana" in one of the Annuals released way back in 2005 or 2006.
• ...Donna.
  • Donna did turn into a (half) Time Lord in "Journey's End", so it's perfectly possible that at some point she will regenerate and somehow end up on Gallifrey.
  • The Lady affectionately refers to Wilf as "old soldier", which makes it sound like she knew him personally before she even contacted him. Donna is the only person we know of who both has a personal connection to Wilf and could one day become a Time Lord.
  • After Wilf asks the Doctor who she is, the Doctor looks at Donna and the camera focuses on her. The Doctor must've realized that at some point Donna will be able to integrate with her Time Lord side and will regenerate into the Lady. However, he doesn't want to tell this to Wilf, because he fears that Wilf might try to speed up the process and inadvertently cause Donna's brain to fry.
  • The Lady seems to know the future, and she tells Wilf what he must do in the days to come to help the Doctor. It's possible that Donna learns to cope with her Time Lord mind before Wilf dies of old age, so Wilf is able to tell here what happened during "The End of Time". And when a future version of Donna realizes those events are about to happen while she's on Gallifrey, she knows just what to do.
• ...Susan.
  • Wilf asks the Doctor who she is. The Doctor's answer is to Glance Significantly at Donna. Need I say more?
  • So the Doctor was telling Wilf "That woman you saw is to me what Donna is to you [granddaughter]?"
  • This theory also explains the Church Lady's otherwise enigmatic comment about being "lost... so long ago."
• ...the Doctor's mother.
  • She's a Time Lady, looks pretty old, tries to help Wilf save the Doctor's life — and the Doctor's reaction when he sees her.. Sorry for not making this clearer, for people who haven't seen the episode yet. But if you have, you'll understand.
  • Word of God confirms this. The commentary for part two has RTD saying that's who she is. HOWEVER, since this wasn't confirmed in story, and with RTD no longer involved in Doctor Who, this could change.
  • It should also be remembered that RTD delights in being a lying liar who lies. He has said things more than once that were proved lies within a season.
• ...Susan's mother. (i.e. either the Doctor's daughter or daughter-in-law.)
  • Why not?
• ...Ace.
  • The EU is rather... confused about her eventual fate (with The Sarah Jane Adventures notably giving a different answer to the one required for this theory to work), but the original plan, also used in Death Comes To Time, was that she would join the academy and become a Time Lady - and given how soon the Time War follows... This gives us a great chance to bring her back.
• ...Flavia.
  • She was actually Acting President in the Doctor's place at one point.
• ...the Rani.
  • Just For the Lulz.
• ...Jenny.
  • That would mean the Doctor suddenly realised that there might be an opportunity to prevent the Time War. That would be a twist.
• ...the Master.
  • Don't tell me it wouldn't be hilarious.
• ...the White Guardian.
  • She was dressed all in white, knew exactly what to tell Wilf to get him to do the right thing at the right time, and randomly appeared and disappeared without obvious technological help. And considering that the Rassilon and the other Time Lords where trying to destroy time (and the Doctor trying to control time in The Waters of Mars), it would be weird if she didn't show up to nudge things back in the right direction.
• ...Rassilon.
  • The Doctor was calling her "Rassilon", not the Lord President.
  • Jossed. Rassilon turns up again in Series 9, still Lord President, and wanting revenge on the Doctor for, among other things, stopping him in "The End of Time".
• ...the TARDIS.
  • Whenever she appears onscreen, the TARDIS's theme starts playing.
• ...all of the above.
  • She's not Susan, Romana, Jenny, Donna, or the Doctor's Mother: She's all of them. Each woman took turns taking in that form, for reasons I still haven't quite worked out yet, but they did one goal: The above theory about setting up Ten's regeneration.
  • When Ten and Donna pretended to be brother and sister, a Roman commented on their family resemblance.
• ...playing everyone.
  • Expanding on previous theories, Donna can't consciously use her timelord knowledge, but she can use it unconsciously. That was how she led Wilf and the Doctor to where the Master was. She gets in contact with either, Susan, Romana, Jenny, or The Doc's Mom, and they all conspire together to save both the Time lords, and the Doctor himself. First,The time lady, as any of them besides Donna (at least the Donna of the present) guides Wilf to the Doctor at just the right moment (something the Doctor himself is starting to notice. Because it's through Wilf that he gets the message about where the Master is, and the weapon that allows him to defeat Rassilon. Now the Gun is important. Why? Because both Rassilon, and the Master had to believe that the Doctor is willing to kill one of them to save others. If he had just used his Sonic Screwdriver, the Master might not have performed his Heroic Sacrifice, and the Doctor would have been killed by Rassilon, ensuring that the Timelords really were all gone. Next while all this is going on, The Time lady gathers up other Timelords who weren't on board with Rassilon's plan (but kept their mouths shut in order to ensure they weren't caught) haul ass off the planet so that when the Doctor sends it back, they don't get caught. But wouldn't they still be pulled back when the link is broken? Nope, cause they made their own link: Wilfred. Hence another reason for the Time lady's contact with him. Whether it's permanent or not, I can't say. Finally, as many here have pointed out, Ten had a few issues. He was a good guy at heart, and he always tried to do right, but as The Waters Of Mars showed, this could go wrong. The Doctor was heading down a dark path, and as the people who loved him most, they decided that they had to save him. The problem was, Ten really liked his current form, and would likely never willingly regenerate (he might not even no how) so once again, Wilf comes on the scene, as it would clearly take a situation like saving a friend to get the Doctor to willingly put himself in a situation where regeneration was likely. As Eleven, he will hopefully learn from his previous self's actions, both good and bad, and eventually, the escaped timelords may reveal themselves to him, allowing him to move on completely. The only flaw was that one of them needed to be there to trigger the Doctor's ephiphany about how to stop Rasillon, meaning that either Susan, Roman, a future version of Jenny, a future version of Donna, or the Doctor's own mother is trapped back in the Time war, but it was a small price to pay to save their people
• ...responsible for saving the Doctor's life.
  • The prophecy is that he would die, but as Ten himself reveals, Regeneration (to him specifically) is just like death. There were two interpretations of the prophecy. One where he dies for real, and one where just the Tenth dies and regenerates into the Eleventh. Her communicating with Wilf, convincing him to come along, and in turn bringing his service revolver, which the Doctor finally took when it seemed the Time Lords were returning was all part of a big plan to have all the right tools in place to allow the Doctor to continue living in a new form.
• ...the former wife of the Doctor.
  • And Susan's grandmother. The First Doctor was pretty old physically (he must have been in that same regeneration for a long time), like she is.
• A later form of the Doctor.
  • Why not?
• An aspect of the Doctor's psyche
  • The War Doctor knew that there was a chance the Final Sanction would work behind his back, and wanted to make sure when the time comes he'd have the will to stop it. The Woman is similar to the Dream Lord in that she is part of the Doctor's personality, and like the Valeyard was given physical form somehow. She represents the Doctor's pragmatism, comforting him/herself into being capable of pulling the trigger. The reason why she spoke to Wilfred was because of his and the Doctor's close friendship, making it easier on 10 when he kills the Time Lords a second time.
• The Moment.
• Dio Brando.
  • You thought this guess would involve a character from Doctor Who itself, but it was actually him, Dio!

The Tenth Doctor's superhuman stamina/endurance was what enabled him to put off his Regeneration for so long.

While not Superman-powerful by any stretch, Ten would qualify as a superhuman given some of the things he endured: massive radiation (at least the kind in Smith and Jones), getting electrocuted on top of the Empire State building, arsenic, and the insane jump he made in "The End of Time".

The Master is attempting to bring the Time Lords back... and will succeed

Mostly because several sources are claiming it, but also because he seems very annoyed they're gone. His reaction- almost angry, then disbelieving- in tSoD, his insistence he's making a new Time Lord empire... it stands to reason that if he can come back in the last two specials, he'll pick right back up. But this time... well, maybe he'll succeed. (After all, on a more practical level: the Time Lords being gone comes across much more as a built up, RTD story arc than anything. It makes sense it'll end when RTD leaves, with actual resolution, rather than stay a background aspect of the universe.)

• Status: Confirmed AND Jossed.

The regeneration device didn't fix the Master.

It used him as a template. He's still dying, but now everyone else is too.

The Master is the reason why the Time Lock is still in place.

Which is why Rassilon had to use the rather round-about way of using the Master himself to break out. After all if the Time Lords established a time lock surely they had a way to get out of it? Granted the Daleks or the Doctor may have had a hand in this, but if the Master had a way to get out he may have had a way for everyone else to stay in. Either he stole the key to get out from the Time Lords or the Daleks stole it, which is what the Cruciform was about and he took it. He then used to to get out, and lock the door before travelling far enough through time and space that no matter who wins he'll never be found. Rassilon giving him the drums was in part revenge for deserting them like that. As for the key, it's probably stuck in the same era of Utopia, buried deep from any of their clutches. The Master's not stupid enough to use it.

The Ultimate Sanction would've made the Time Lords Eternals.

The Ultimate Sanction's plan was to destroy time itself, allowing Rassilon and the Time Lords to become creatures of consciousness alone existing outside of time^note by default. Sounds similar to the Eternals, beings from the Classic Series who exist outside of time and have godlike power over those below. It might explain why they fled the universe, though it's also possible some of the Eternals wanted the new company and that's why they didn't interfere.

The "I don't want to go" didn't actually come from the Tenth Doctor.

It came from the remnants of John Smith left in his mind, who doesn't know if any of his personality will still be around after the Doctor regenerates.

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