Finally, a truly great episode of Doctor Who!
Extremis dispatches with the rather tired monster of the week format while finally giving us the big reveal of the series: the answer to who is inside The Doctor’s box. With a truly intriguing premise and what appears to be a villain able to match wits with The Doctor, Extremis is the best episode of this series to date.
The episode opens with a flashback. One thousand years ago a Time Lord was about to be executed. The Doctor is told that the device is intended to completely kill a Time Lord and stop their regeneration. The Doctor is told that the execution must be performed by another Time Lord, and the executor apologizes for their choice but Time Lords are hard to find. Missy appears, and for a brief moment we are led to believe that it is The Doctor who will be executed. However, the executor demands that the prisoner kneel, and after a brief beat Missy is forced to kneel upon the execution apparatus.
One thousand years later The Doctor is still blind, and must rely on his sonic sunglasses which gave him a limited ability to see.
In the prologue of this episode, as well as in Nardol’s speech at the end of the previous one, it is implied that the greatest danger is that The Doctor’s prisoner would learn that he is blind. However, it seems that the greatest danger to The Doctor are the enemies from without, rather than whomever it is he has trapped in the box.
As The Doctor is contemplating his weakened state, The Pope arrives and asks for help. It seems that there is a book that has existed for centuries named “Veritas” (literally “The Truth”) which has now been translated into English. Any and all who read this book kill themselves. Naturally, The Pope wants The Doctor to read this book.
And while Bill is on a date with a young woman in her apartment, The Pope walks into the room. This was a stupid scene, but so stupid as to be funny. Bill’s date is scared off by the appearance of a very frazzled Bishop of Rome, and Bill goes inside the TARDIS to have it out with The Doctor. This scene shouldn’t have worked. It doesn’t match the tone of the episode (something very reminiscent of The King in Yellow), and the levity is a tad out of place for such a dark episode. But it works.
With Bill collected (not knowing that The Doctor is still blind) the crew ventures to The Vatican. There, in a hidden vault of heretical documents they discover the last surviving translator. He had locked himself within a cage containing Veritas. He’s emailed the Veritas document to CERN, which is a physics research facility in Switzerland. Look it up.
This part of the episode is a bit slow, but necessary to further the plot. The translator escapes and kills himself. Nardole and Bill investigate and find luminous portals to other locations on Earth. One of which is CERN. This bit is never really explained fully, and to be perfectly honest it’s the one major plot hole in the episode. But I was so enthralled with the mystery that I failed to recognize it until after I began writing this review.
At CERN they discover the staff are about to kill themselves. As an explanation for their motives a scientist asks Bill and Nardol to recite random numbers. They do, discovering that they recite the same random numbers. Every time.
This is one of the most important parts of the episode, and gives away the entire riddle without the viewer realizing it. Nardole discovers the truth first. Returning back to the portal generators, Nardole realizes they the beams of light are projecting holograms, rather than portals. He reaches his hand behind the generator, hoping that he’s wrong. He’s not. Nardole is disintegrated, crying in fear.
Meanwhile The Doctor attempts to read the document, stealing a bit from his future in order to gain sight for a few moments. However, the creatures the internet is calling The Monks appear. These Monks are terrifying, with half melted eyeless faces and a slow, almost zombie like motion. They inform The Doctor that this is a game. Everything is a game.
Nardole has disappeared, and Bill follows The Doctor through a portal into the White House. The President had killed himself after reading Veritas, which The Doctor had also read. Bill doesn’t understand, but the audience by now does.
They are all in a simulation. A war game, really. One that is so sophisticated it is a solipsistic nightmare: indistinguishable from reality. But it has one flaw: Random Number Generation. Computers don’t actually generate random numbers very well. One method of testing if you’re in a simulation is to create a string of random numbers. Computers aren’t particularly good at RNG, especially when multiple systems have to do it at the same time. The Doctor explains to Bill that they have all been trapped in a simulation. A nearly perfect simulation, one used by an alien force in order to gather data and plan and invasion.
This is a truly emotional scene, especially for Bill. She’s been fighting the realization that she was a simulation for sometime, and is unable to accept it even when the simulation ends and she disintegrates. This scene in particular is one of the ones that makes this series truly great, despite the lackluster episodes that have preceded this one. The scene in which The Doctor explains the harsh reality of their nonexistence to Bill underscores the amazing chemistry these two have. It’s a chemistry that this Doctor never truly had with Clara, even though some of her best episodes were those with The 12th Doctor.
The scene of Missy’s execution is one that is visited multiple times throughout the episode. As The Doctor is about to execute Missy, having sworn an oath to guard her lifeless body within a vault for a thousand years, a hooded figure approaches the scene. It appears that The Doctor has requested the presence of a priest.
The doctor approaches and we learn that it is Nardole, who reads to The Doctor from the Journal of River Song.
Only in darkness are we revealed. […] Goodness is not goodness that seeks advantage. Good is good in the final hour, in the deepest pit, without hope, without witness, without reward. Virtue is only virtue in extremis. This is what *he* believes, and this is the reason above all I love him, my husband. My madman in a box. My Doctor.
The Doctor returns to the scene of the execution and pulls the lever of the device. Missy falls to the ground. But she is not dead of course because the doctor is neither a murderer nor an executor. He is simply The Doctor.
This was a brilliant way to reveal the secret of The Doctor’s vault, something that most viewers had guessed even before this episode aired, but it gave meaning and gravitas to the revelation. And of course any scene that involves Michelle Gomez is a delight to watch.
Back in the simulation The Doctor confronts one of The Monks. When The Doctor asks why they don’t shut him off, The Monk replies that they are still gathering valuable information about him. But they have made a mistake. Simulation is too complete. The Doctor has been wearing his sonic sunglasses the entire time, recording everything. And since the sunglasses are psychically linked with The Doctor, he can email a message to his true self.
The Monk: What are you doing?
The Doctor: What everyone does when the world is in danger — calling the Doctor!
The real Doctor receives a message entitled “Extremis” and solemnly laments to Missy that his enemies are coming and they know he has been weakened. He asks her, begs her, to help him.
The solipsist dilemma that this episode presents is hardly unique, but the execution is superb. It’s a hard question to answer, whether or not you can tell if the reality you perceive is real. But at least in the world of Doctor Who, we know that The Doctor will always be The Doctor even if he isn’t real.
This is the first truly great episode of this series. Although we saw far too little of Missy, and Bill had almost no interaction with The Doctor, one can forgive these minor lapses considering the quality of the writing. There were a few plot holes, especially the glaring one of why the aliens would build a simulation that allowed for portals to different parts of their world, but these can be ignored in face of the overwhelming quality of the episode.
As a character piece this episode is unparalleled in its ability to explore how The Doctor will behave when he is at his weakest.