Ham-sa108

We know UNIT is going to be appearing in the three-part storyarc that begins in “Extremis,” in which we will learn who’s in the vault.

It seems plausible to me that UNIT has something to do with how and why the Doctor is guarding a vault at a university on Earth.  Honestly, installing a vault on Earth and then sticking around to guard it for decades--possibly forever or at least for 12 more regenerations--does not seem like the most reasonable plan the Doctor could have settled on. And not just because it’s a plan that requires a lifestyle that is not at all compatible with the Doctor’s nature. It just doesn’t seem like the best plan for guarding/protecting the person in the vault. Why not keep the vault in the impregnable, indestructible TARDIS, which could have created the vault as easily as she creates new console rooms--and probably a more impregnable vault than you’d find most anywhere else at that? Plus, keeping the vault’s location unknown to anyone who might want to break out the prisoner would be better served not by installing it in one time and place--and pinning down its location to be discovered--but by keeping it on the TARDIS which is constantly hopping randomly through all of time and space based on her momentary whims and the Doctor’s.

So it seems to me that, if the writers are on their game, there must be reasons why the Doctor is on Earth. He needs to have found himself in a circumstance in which promising to stay on Earth indefinitely to guard this vault was the best option he had.  One possibility could be that someone was about to kill whoever is in the vault--for revenge, to protect the world/universe from them, for any number of reasons--and the Doctor bargained for their life by promising to make it his personal mission in life to ensure this person did no more harm if they were allowed to live. I can see him doing that for Missy/Master, the frontrunner for Most Likely to Be In the Vault among fans and the media. I can see him doing it for anyone he cared about--or even for a random stranger, in fact, depending on the circumstances. Indeed, he might have been willing to do it not because of who was about to be killed but because of who was about to do the killing (as when he was willing to kill Missy to keep Clara from killing her). I can see Kate Stewart or some other UNIT agent insisting that he would stay on Earth to assume his guard duties before she (or he) would agree to let the person live if he would guard them forever. It was UNIT (under Stewart) who felt the need to drug, kidnap, and handcuff the Doctor until he was essentially trapped on a plane in flight without his TARDIS to ensure that he would do what he could to save Earth (”Death in Heaven”). Kate said her father would have done the same. UNIT/Kate Stewart (and apparently Gen. Lethbridge-Stewart too) likes to be in control. UNIT went so far as to do background checks on all the Doctor’s companions, even abducting them and wiping their memories afterwards, as if it’s their right to make sure the Doctor chooses his friends well. It’s controlling and paranoid and creepy. So I can definitely see Kate/UNIT roping the Doctor into spending the rest of his life on Earth on the slow path to serve her/their needs--and not just for safety but for control.  I have not watched Classic Who (it’s hard to) but I did learn that UNIT has its origins as an organization in Earth’s 1960s. Lethbridge-Stewart first appeared in a serial called “The Web of Fear” set in (variously stated) 1968 or 1969 (or approximately 1975 but ignore that LOL). It’s the storyarc in which the 2nd Doctor faces the Great Intelligence in the London Underground--mentioned by the 11th Doctor in “Snowmen” as he flashes a map of the London Underground, 1967, at the man he has figured out is/will be the Great Intelligence. Within four years of this first meeting with the Doctor, Lethbridge-Stewart is heading up the newly formed UNIT.  Could the vault in 2017, guarded since (maybe) about 1967, have something to do with the Great Intelligence in 1967? ;-) Or at least with Lethbridge-Stewart and UNIT, perhaps even UNIT’s origins?