History YMMV / DoctorWhoS36E12TheDoctorFalls

* UnexpectedCharacter: The First Doctor, as past Doctors usually only come back for multi-Doctor anniversary specials. And in the revival, the only ''vintage'' Doctors to have an actual, non-stock footage onscreen role up to this point were the Fifth and Eighth ones, whose original actors were both still alive and in good enough physical shape to act (Tom Baker is suffering from arthritis). Eventually, Colin Baker and Sylvester [=McCoy=] would return as the Sixth and Seventh Doctors [[Recap/DoctorWho2022CENThePowerOfTheDoctor at the end of the next Doctor's era]], alongside the First, Fifth and Eighth.

* OnlyTheAuthorCanSaveThemNow: The Doctor is already PowerfulAndHelpless to find a way to restore Bill's humanity under the circumstances, but this trope doesn't kick in until he falls on the battlefield in a way that precludes regeneration. If not for Heather, who's regained her personality ''and'' gained new abilities since last seen, arriving as Bill weeps over the Doctor's body, KilledOffForReal would be the only fate left for the Doctor and Bill. This trope also applied to the Master down the line -- Missy is last seen dying and unable to regenerate in the woods before Floor 507 is blown to bits, but they are the show's most popular standalone villain and has JokerImmunity on their side, ultimately returning in a new form at the top of Series 12.

** The Master is shot, does not regenerate, and is likely burned to ash... [[Recap/DoctorWhoS21E5PlanetOfFire Like that's]] [[Recap/DoctorWhoTVMTheTVMovie ever stopped]] [[Recap/DoctorWhoS29E13LastOfTheTimeLords him before]].

* ShockingMoments: Many, many things, from Bill and Heather reuniting, to Missy betraying her past incarnation, to Mr. Saxon betraying his ''future'' incarnation, all generations of Cybermen, archival footage of most revival-era companions (including Clara, implying that the memory block Twelve put on himself at the end of "Hell Bent" was lifted, but barring Mickey and Rory... and [[MyFriendsAndZoidberg Adam]]),[[note]]The former two didn't really spend a lot of prominent time with him on their own- they often took a backseat to their love interests or came bundled with them; Mickey even decided to leave because he felt overshadowed. The latter got the boot for bad conduct on day one aboard the TARDIS, then became a TragicVillain when he [[DeathByAdaptation returned in the comics and got killed ]][[RedemptionEqualsDeath in the act of choosing to make amends]]. Leaving Rory out is gonna leave a lot of unhappy fans, though![[/note]] and the return of the First Doctor, now played by Creator/DavidBradley.

** Similarly, their having the "Death in Heaven" breed's rocket powers. In an episode showing off the ''different'' portrayals of the Cybermen over the decades, right down to "The Tenth Planet" breed's speech pattern, all of them take too much from the most recent brand. (Somehow, though, no one minded when the same was true of the Dalek variants in series 9's premiere episodes; of course, nobody really misses the days ''trying to go off the carpet'' was enough to stop a Dalek). The fact that the Master had some involvement in these Cybermen's development possibly justifies this, especially if Missy ''got the idea'' for flying Cybermen in Series 8 from lingering memories of her previous self having seen them.
** Some aren't too keen on the idea that the Cybermen evolved naturally on several different planets besides Mondas, {{retcon}}ning the long-standing assumption that the Cybermen's presence on other planets was the result of colonization and conversion of the natives by the Mondasian Cybermen.
* UnexpectedCharacter: The First Doctor, as past Doctors usually only come back for multi-Doctor anniversary specials. And in the revival, the only ''vintage'' Doctors to have an actual, non-stock footage onscreen role up to this point were the Fifth and Eighth ones, whose original actors were both still alive and in good enough physical shape to act (Tom Baker is suffering from arthritis and Colin Baker has gained significant amounts of weight due to diabetes; Sylvester [=McCoy=] ''could'' potentially return at some point, though he is in his 70s).

* AuthorsSavingThrow: The Twelfth Doctor mentions how Cybermen always show up wherever humanity and humanoids in general go -- "parallel evolution" he calls it, which not only means that the Big Finish Cybermen origin story "Spare Parts" is still canon, but also amends the gigantic continuity error that was the Expanded Universe comic "The World Shapers" (in which the Cybermen are depicted as originating from the Voord on Marinus).
** Also, if you wonder how Mondasian Cybermen can look like Cybus Cybermen (in episodes like Closing Time, where WordOfGod declared unaltered new series Cybermen to actually be the Mondasian ones; Steven Moffat wanted to use the originals but the budget to make a bunch of old-school Cyberman costumes wasn't there, but that left us without an InUniverse explanation.) This episode sheds light on it - apparently, Cybermen originate in ''way'' more than just two places and usually end up looking quite similar; every origin will probably create every variant given enough time. This explains pretty much any instance of any sort of Cybermen being where they're not supposed to throughout the series in ''any'' era.
** And, of course, if that still isn't good enough for an old-school Cyber-fan, say hello to ''three generations together.''

** Also, if you wonder how Mondasian Cybermen can look like Cybus Cybermen (in episodes like Closing Time, where WordOfGod declared unaltered new series Cybermen to actually be the Mondasian ones; Steven Moffat wanted to use the originals but the budget to make a bunch of old-school Cyberman costumes wasn't there, but that left us without an InUniverse explanation.) This episode sheds light on it - apparently, Cybermen originate in ''way'' more than just two places and usually end up looking quite similar; every origin will create every variant given enough time. This explains pretty much any instance of any sort of Cybermen being where they're not supposed to throughout the series in ''any'' era.

* ItWasHisSled: The First Doctor appears at the end. It helps that the promotional material for "[[Recap/DoctorWho2017CSTwiceUponATime Twice Upon A Time]]" heavily featured the First Doctor.

** One group felt this is the happiest ending a companion could ever get, [[EarnYourHappyEnding and that it was well deserved]] [[TraumaCongaLine after all the heavy shit she went through]]. Also, it subverted StuffedIntoTheFridge and avoided BuryYourGays, which both would have been played straight had she died.

** And, of course, if that still isn't good enough for an old-school Cyber-fan, say hello to ''every variant ever seen!''

* MemeticMutation: Near-instantaneously, the moment where the Saxon Master cockily says, "See this face? Take a good... long... look at it. This is the face that didn't listen to a word you just said!" exploded online in both video clip and GIF form, because many people surmised right away it could be used as one ''hell'' of a forum weapon.