OK, as alien invasions go, one that makes it look like the aliens were always there is an interesting twist.
Also, Bill’s mom saves the day.
So, apparently, the Monks set up some kind of system where the greater humanity believes they’ve always been on Earth, guiding humanity at every step along the way, as these sort of benevolent authority figures who still demand love and total obedience. Anyone caught trying to remind people the Monks only arrived six months earlier is arrested and taken away. Bill, narrating events to her dead mother as a form of self-therapy, is doing her best to keep her head down.
Then Nardole shows up at her front door, totally fine. He got that bacteria, and his alien body needed a few months to recover. He also knows where the Doctor is, seeing as how the Doctor is making propaganda videos for the Monks.
For an episode like this, it comes down to the Doctor’s needing to find a way around some sort of all-encompassing memory alteration. The Monks must have a machine of some kind that does that, and he needs to be extra careful finding allies. He actually is able to do that, but his allies are basically Nardole, a few military types, and…that’s it. Bill has to pass a test to see if she would turn on the Doctor if he berated her enough and suggested the Monks were necessary because humanity had too many problems, at least the Monks were semi-benevolent because it could have been a much worse race–Monk propaganda suggests they defeated the Daleks, Cybermen, and Weeping Angels in the past–and yes, Bill will steal a guard’s gun and shoot the Doctor. He’ll even fake a regeneration a few episodes early. But no, Bill is sincere. Good joke. Good thing she didn’t take a gun from the one guy who forgot to switch to blanks.
Why did the Doctor think Bill would know a regeneration when she saw one?
So, yeah, now the Doctor can save the day. Why wait? He needed more help. That means asking Missy more directly. Missy gave up evil cold turkey, and sure, she could escape the vault any time she wanted to, but she’s taking her punishment like she should. And yes, she has encountered the Monks before and knows exactly how to defeat them: just take out whoever gave consent because that person’s brainwaves are being used to power the fake memory machine.
That would be Bill, and the Doctor will always look for another way. Though I was interested to note this episode may be the first time the Doctor suggested Missy/the Master is only almost as smart as he is.
But really, this was an episode for Bill to save the day. The Doctor can’t this time. The plan to break into the Monks’ pyramid base and overload the brainwashing machine with the Doctor’s own mind doesn’t quite work, even if the highlight there may be the fact Nardole knows his own version of the Vulcan nerve pinch. Bill can try by putting herself into the machine, but her mind kept going to one memory: her own mother. A pure love for a figure of overwhelming goodness in Bill’s mind then goes out to, oh, everybody, and the Monks are chased off the planet. Plus, since the Monks mess with memories, they can easily make the world forget they ever came by, so status quo returned.
But hey, Bill saved the world, and the Doctor does explain why he bothers if humanity has done so many stupid and harmful things: because there are still people like Bill in the world.
Or maybe Bill’s mom. She sounds like she was awesome for a character seen only in some silent images.