|The Doctor discovers a long lost secret Harry Potter novel.|
A long time ago, we learn about the Doctor's oath, how and why he swore it, who he swore it for. Yes, we know who is in the vault.
Today, the Doctor is still blind when he gets a visit from the Pope. Apparently some weird stuff is going down in the Vatican. An ancient text called The Veritas has been translated and anyone who reads it immediately commits suicide. So the Doctor, Nardole (filling in whatever the sonic glasses can't convey to the Doctor) and Bill (whose date with a woman named Penny gets interrupted by the Pope) are off to a secret chamber deep underneath the Vatican.
There the gang discovers a cardinal with the Veritas... and a laptop with a translation of the Veritas. The cardinal says he's "sent it", then runs away. A gun shot later tells us that another reader of the Veritas has taken his own life.
There are portals opening up in the secret chamber. While the Doctor is working on reading the Veritas (yes, he's blind; more on that in a minute), Nardole and Bill explore the portals which are transports to different parts of the world. In one of them, Bill and Nardole discover a group of nuclear scientists who have read an emailed translation of the Veritas (that'll teach you to click on those questionable links in your emails) and are preparing to blow themselves up in a mass suicide.
Escaping from the suicidal scientists, Nardole realizes that the portals are not transporting them to other parts of the world but are holographic simulations. Then he discovers to his horror that he too is a simulation and vanishes. Bill is a bit bugged out by this and she follows a trail of blood through a portal, in search of the Doctor.
Backing up a bit, the Doctor is trying to jump start his eyesight to read the Veritas. The Doctor is borrowing from his future to be able to see but time is running out. Yes, there are aliens behind all this, tall, gaunt aliens of rotting flesh (yuck!) cloaked in red hooded robes. One of these alien monks takes the Veritas but the Doctor escapes with the laptop that has the translated Veritas on it.
But whoops! The Doctor's eyesight is fading again as he stumbles through a portal.
Which brings us back to Bill whose portal takes her to the White House to find that the president has killed himself because he too read the Veritas. The Doctor is there behind the Oval Office desk. He's read the Veritas. Or rather, he used an app to have it read to him.
The Veritas is the story of demons come to Earth to conquer it but create their own Earth to learn about Earth and practice how to best conquer the real thing.
This world, the Doctor tells Bill, is not the real thing. It is a simulation and they too are simulations. Bill vanishes with this knowledge. Leaving the Doctor alone with an alien monk. "The Doctor" tells the alien they made this world too good. His sonic sunglasses have been recording everything. The simulated Doctor sends all this information via an email...
To the real Doctor waiting outside the vault and his sonic sunglasses. Brought up to speed, the Doctor calls Bill who is not on a date with Penny as she thinks Penny is way out of her league. The Doctor says no, Bill should call her... NOW, in fact. Something is coming, something very bad and the Doctor thinks they're going to be very busy.
OK, let's get this out of the way.
WHO'S IN THE DANG VAULT?!?!
Well, it's Missy.
OK, bit anti-climatic. The most common guesses involved the Master, either Michelle Gomez as Missy or John Simm's version. The story of the vault, who is inside it and the Doctor's oath to guard it is told in flashback. Missy is set to be executed and the Doctor, as a fellow Time Lord, is there to act as witness and executioner. The process also includes an oath to guard the body for a thousand years in case, you know, the deceased tries something.
The Doctor appears to carry out the execution but he may have messed with the wiring bit. Missy isn't dead. The Doctor notes he made an oath to guard the body but there's nothing in that oath that says that the body has to be dead. Nardole helps the Doctor put Missy in the vault.
So Missy's in the vault.
C'mon! This is Steven Moffat we're dealing with. We still have not actually seen inside the vault. We're presuming a lot of things that have not been confirmed. Like actually seeing Missy in the vault.
Extremis is a particularly mind trippy episode as it goes full bore Inception. What we think is real isn't real. It really pulls the mind into a knot to realize that the bad guys have been controlling the game from the point the Pope and his posse of Cardinals come calling on the Doctor.
Nardole gets a couple of bad ass scenes in this episode with his appearance at Missy's execution and his standing up to Bill. Don't mess with the only person in the universe who has been officially sanctioned to kick the Doctor's ass.
We find out the Daleks love to gossip about the Doctor. Missy mentions she knows the Doctor has been on Darrilium because that's what the Daleks say.
Dalek 1: How are you doing?
Dalek 2: Exterminate this! Exterminate that! I need a break.
Dalek 1: Did you hear what's up with the Doctor?
Dalek 2: I heard the Doctor was on Darrilium.
Dalek 1: Yeah. And he's there with his wife!
Dalek 2: His wife? No way!
Dalek 1: Yes, way! It's his last night with her before he meets her for the first time!
Dalek 2: Bugger! You need a flow chart to make sense of this.
Dalek 1: Tell me about it.
Dalek 2: Well, time to get back to work. Exterminate!
Dalek 1: Exterminate!
All joking aside, things have taken a darker turn from the previous episodes and not just literally for the Doctor who is still blind. It has been established that Time Lord's can regenerate at will, not just in a time of crisis; seems a quick regeneration would fix up the Doctor's vision. Maybe that will still happen. But we've seen regeneration has a re-set; the Doctor goes back to his current form before changing to a new body. So the Doctor could regenerate in the next episode (for example) but not change form until, say, the end of the 2017 Christmas special.
There's a lot to think about has we head into the back half of Series 10 and Peter Capaldi's swan song as the Doctor.
Until next time, remember to be good to one another.