Why did Chibnall wait until becoming a reviled show runner before producing stories like this? This episode may be up there with some of the most intriguing of all of Doctor Who, such as Warriors Gate. Or maybe it's too straight-forward to rank with Warriors Gate, I'm not sure. Regardless, there is a lot to unpack in this, the third episode of the six-part story which is season 13 of Doctor Who.
BTW - this is Season 13 of a show that restarted in 2005, and it is currently 2021, so shouldn't this be Season 16? Oh, right, the BBC skipped a couple years. That's the problem with modern Doctor Who, is that the BBC hasn't been dedicated enough to the cause to keep it on a regular schedule. But that's a distraction, I need to stay with the time stream rather than jumping between time streams.
Which is what this episode was about - that effect we have where we're in the middle of some bit of life, like walking down the street, and all of a sudden our mind is somewhere else, remembering a story from earlier in our life, or projecting into a future life, or having a thought of a completely different life, or whatever.
Inside humans is an associative data store where all our memories are stored. To access a memory, what's needed is the associated memory. Like, to remember this specific restaurant at a highway interchange on a road we rarely travel, we need to pull up the memory of an event which happened while driving down that highway just before we decided to go to that restaurant. And accessing that memory means pulling up memories of other arguments with other people. That's what this episode was like.
The Siege of Atropos
Even though this was a time-wimey episode with lots of twists and turns, one sequence of events is clear as a bell. The Doctor, Yaz, Vinder, and Dan, were all thrown into the Time Stream, and reliving various events. For Vinder, that meant reliving when he rated on the political leader. For Dan, that meant his relationship with Diane. For Yaz, that meant reliving being a police officer, and time with her sister. But, for The Doctor, that meant reliving The Siege of Atropos.
Therefore - sometime in The Doctor's previous incarnations, way in the past, thousands of years ago, when Swarm and Azure were actively fighting with The Doctor, there was a battle where The Doctor, and helpers, attacked and invaded The Temple of Atropos, in order to capture and subdue Swarm and Azure.
The image above is the first stage of that battle, when the four of them were outside the Temple preparing the final assault. In another phase, they were in front of the main gates, and set off a device to break through the gates. In another phase, they were in the tunnels, The Doctor saw the Fugitive Doctor in a reflection. In another phase, they entered the Temple chamber, faced down Swarm and Azure, and released the Moori who had been captured by one of the Passenger creatures.
This was when Swarm and Azure were put into the prisons from which we saw them escape in the 1st episode of this season.
There's a lot more to say about that in We finally know where The Fugitive Doctor fits into The Doctor's history
Bel and her Emoji Box
Commander Vinder has a past, and has people who care for him, and who he cares for. This isn't going to be one of those instances where The Doctor's Companion meets someone, falls for that someone, then decides to Leave The TARDIS to be with that person. No, Vinder has someone, and therefore Yaz doesn't get to ride off into the sunset with Vinder.
Vinder's woman seems to be an Agent of some kind, of the same level of accomplishment as Vinder.
Vinder was put through memories from earlier in his life, of having been a top level servant of his military, and having served "The Serpent" - a top political figure. But then he witnessed this guy make a nasty deal, for which Vinder reported the guy, and was then punished by being posted to the remote observation outpost.
Isn't this oh so much like Lt. Col. Vindeman who reported Pres. Trump for attempting to make a nasty deal? The general outline of Trump's deal, and The Serpent's deal, are roughly the same, vaguely. It's not the first time that Doctor Who has shown something roughly related to concurrent politics.
In any case - I'm sure that Bel and Vinder are very cute together, and they deserve to be together.
I'm very curious how it is she knows so much. Would the average person in that situation know about The Flux and the relative distribution of various forces like The Daleks or The Cybermen? No. How could she have a space ship that has a dashboard GPS system which is instantly updated with the latest distribution of Daleks and Cybermen in the Universe? This doesn't make much sense.
How she knows so much is likely due to her being a high level Agent of some kind. But how does her spaceship have such accurate data about the location of Daleks/Cybermen/Sontarans/etc?
And just what is the military force which Vinder and Bel worked for? Are they related to The Division?
Mason Street, near Edge Hill, that's near where Dan lives
The Williamson Tunnels are an series of extensive subterranean excavations, built for an unknown purpose, in the Edge Hill area of Liverpool. These were built between 1810 and 1840 by Joseph Williamson, the guy with the studly sideburns in these episodes.
If there were anything in England deserving of coverage by Doctor Who, it's these tunnels.
It's possible that The Temple of the Moori - notice that this is in a series of stone corridors - are meant to be related to these tunnels.
Williamson leased/acquired the land around Mason Street. The north end of this street is in the Edge Hill area. At the other end of Mason Street is a museum, the Williamson Tunnels Heritage Centre. Mason Street itself doesn't look like much, some not-so-good apartment buildings on one side of the street, and derelict buildings on the other side. But in the early 1800's, Williamson (a wealthy man) built his house on this street, so it may have been a more posh location.
Nowhere on that street is a segment which looks like Dan's neighborhood. Hence, his house is probably not on Mason Street, but a nearby street, as he says.