Written by Steven Moffat, directed by Daniel Nettheim. Guest star: Michelle Gomez
“They read The Veritas – and chose hell.”
In the Haereticum (the Vatican’s secret library of blasphemy) there is an ancient book known only as The Veritas. Throughout history, anyone who has ever read it has immediately taken their own life. Now a new translation is online, and the danger is spreading. The Vatican appeals to the Doctor. Will he read The Veritas? But can even the Doctor survive the ultimate truth?
On a distant planet, an executioner named Rafando shows the Twelfth Doctor a mechanism especially designed for killing Time Lords. He then tells him that after the execution, the body will be placed in a quantum fold chamber in case of “relapses”. Missy is then brought in, and is ordered to kneel on a dais.
In the present day, sitting outside the Vault, the Doctor talks to Missy, who is inside, saying that no one can know that he’s blind.
Back on the planet, while the Vault rises from the lake, Rafando announces that the chamber is prepared. Missy begs the Doctor to let her live, while he places his hand on a lever.
Back outside the Vault, the Doctor gets a email titled, Extremis.
In the lecture hall, 15 men file in through the back door. Angelo greets the Doctor as Nardole enters. The Doctor is told that the Pope requested a personal audience with him. When he asks why he did not come there himself, Nardole tells him that he is here. The Doctor apologizes saying, “The Pope doesn’t zoom round the world in the Pope-mobile surprising people. Why would you do that?”
In his office, the Doctor is shown a piece of parchment that reads, Veritas, which literally means The Truth. Angelo tells him that an ancient Christian sect translated it, but committed suicide after translating it. A few months ago it was again translated, but again, all of them killed themselves after the translation. All of the bodies had been recovered, except one.
In Bill’s house, Bill has brought a girl named Penny home. Moira, thinking that she has brought a “Poor terrified man home” tells her that she has very strict rules about men, before seeing Penny, and apologizing. Later Bill is pouring a cup of tea when she hears the sound of the TARDIS materializing in her bedroom. When Penny asks what it is, she says it’s the pipes. The Pope then steps in the room and speaks rapidly in Italian before going back to the bedroom. Bill excuses herself and enters her bedroom where she sees the clergymen. Penny sees them, and freaking out, flees. Bill turns to them and says “You’re all going to hell.”
In the TARDIS, Bill angrily berates the Doctor for ruining her date, while he has Nardole explain what is happening to her. Angelo tells The Doctor that the Pope had given him an offer for confession that he had refused and that the offer still stands as he prepares a device to temporarily restore his sight.
On the planet, Rafando asks if the Doctor requested a priest as a cowled figure approaches. As the figure gestures to him to approach, Rafando checks the Fatality Index and says that divine intervention is allowed for 5 minutes. The figure greets him and reads from a familiar diary. The figure pulls back his hood saying that his missus would not approve, reveling himself to be Nardole, who had been sent on River Song’s behalf to prevent him from killing Missy, saying “Warning, I have full permission to kick your arse.”
At Vatican City, Nardole and the Doctor discuss why his blindness should be kept a secret before exiting the TARDIS. Angelo shows them to the entrance to the Haereticum, a portrait of the Pope Benedict IX, which is accessed by turning a candle. Angelo orders them to stay close because the layout is supposed to confuse the uninitiated.
At the planet, Rafando announces that the 5 minutes are over as Nardole pulls down his hood. Rafando orders that the sentence is now to be carried out. Missy asks the Doctor not to kill her, promising she will be good, nearly crying.
In the Haereticum, Angelo shows them the cage where the Veritas is kept. Suddenly a light shines from a wall with a figure in the center, before fading to nothing. Angelo goes off to check the walls for a breach, as the Doctor takes out his sonic screwdriver. They find the missing translator, named Piero in the cage. He tells them he has sent something to somewhere, before running off. A strange clawed hand then seen next to Angelo’s head. Nardole sees that Piero had shot out the lock, as the Doctor says so much for their forbidden library to Angelo, who has vanished. In the cage, Nardole and Bill see Piero’s laptop, which had been left behind. Checking it, they find out that he had mailed a copy of the translation to CERN. As Bill says that it is promising that one person read the Veritas and lived, a gunshot is heard and the Doctor’s Sonic Sunglasses (Which he is using to see) register his life signs dropping. The Doctor orders them to check on Piero, as the sunglasses register life signs terminated. Nardole and Bill accuse him of trying to get rid of them. He promises not to read the book as they leave. He then opens the Veritas, takes out the device and attaches electrodes to his temples.
In the library Nardole talks with Bill as they walk through the corridors. They find a hand holding a gun, confirming Piero’s death. The same light is then seen again. Nardole realizes that it’s a portal to somewhere. Curious, they step through.
In the cage the Doctor ask for help from Angelo as a sinister shadow is cast on a bookcase. He wonder how it will work: it will either temporarily restore his sight, or it will burn out his brain. He activates it and collapses.
On the planet Missy tells the Doctor that she is his friend. When he tells her that it does not matter, she tells him she knows it does not matter saying, “I know it doesn’t. I know I’m going to die. I have to say it. The truth. Without hope. Without witness. Without reward. I am your friend.” The Doctor then pulls the lever, causing lightning to arc out of the spheres on the top of the 4 columns on the dais and strike Missy. Missy collapses and dies as the Doctor swears to guard her body in the Vault for a thousand years.
In a 5-sided building, Nardole, and Bill exit a broom closet, where they are seen by a woman. She asks if they have clearance for floor 3. Asking where they are, the woman tells them they are in the Pentagon. Nardole and Bill retreat back to the closet, where they find themselves in a hub, with projectors arranged in a semicircle which project light on the wall. Stepping through the light, they find themselves in a corridor where they are greeted by Nicholas who takes them to the cafeteria, as they pass a sign that says CERN.
In the cage, the Doctor opens his eyes to find that his sight has been restored. As he wonders about the impact on his regeneration cycle, the same figure seen in the light appears. He asks for its help as it buckles leather straps around him to restrain him. The Doctor notices there are more of them as the figure closes the Veritas and takes it while the Doctor complains. The figure tells him that what they are doing is a game. The Doctor says “Good, because I win.” and uses his sonic screwdriver to turn off the lights as the figure yells his name. The figures restore them, but the Doctor has escaped with the laptop, and with it the translation.
In CERN Nicolas shows them to the cafeteria where he tell the personnel to give their last orders. He tells Bill and Nardole to look under the tables. There they find that the personnel have strapped dynamite to the table legs.
In a corner the Doctor opens the laptop and begins to read the email the translator sent to CERN. Suddenly, the effects of the device begin to were off as the figures surround him. Suddenly a bright white light flares onto the screen.
In CERN, when Bill asks why they are doing that, Nicholas tells them that they are saving the world. When asked how, he replies that this is not the real world. He says that the have not read the Veritas. Nicholas tells both of them to pick a random number and to say it at the same time. When they try, they both say the same number. Nicholas tells them that that is a “Shadow Test”, and apologizes to them as they escape and the building explodes. As they arrive in the hub Bill notices drops of blood on the floor. Inside Nardole realizes that the projectors are actually projecting the locations. To his horror, he figures out that the world is really a holographic simulation. To see if he is right, he steps into the space between projections causing him to dissolve into pixels.
Bill starts to reach out to the space, but steps through another portal. She finds herself inside the oval office. The Doctor reveals that he had listened to the translation, and that it tells of a demon, who wished to conquer the world, and to do that, he created a Shadow World that has Shadow People who think they are real. The Doctor tells her that he has deduced what it means. He tells Bill that it means that an alien race who wished to conquer Earth ran a simulation to assess the abilities of every person on Earth, especially the ones who were smart enough to realize that the world wasn’t real. The Shadow Test works by having people say random numbers. Since computers can only generate pseudo-random numbers, two people doing that will say the same numbers. He tells her that people kill themselves to escape the simulation. Suddenly, Bill dissolves into pixels, revealing the figure behind her. The figure tells him they have killed him many times. The Doctor tells them that they have fallen into a trap the had created: their simulation is too good. He then reveals that since he is linked to the sonic sunglasses, they will have a memory print of the last few hours. He then emails the recording to the real Doctor.
In the real world, the Doctor, after finishing Extremis, calls Bill who tells him she is doing the essay he told her to do. He tells her to call Penny that night. He then tells Missy, that she had told him she was his friend.
On the planet as the executioners go to the dais to take Missy’s body away, she wakes up and pushes them away. The Doctor reveals that he had sabotaged the execution machine into knocking Missy out instead killing her. After scaring the executioners away by tricking them into accessing his record of fatalities, the Doctor has Nardole help him move Missy to the Vault.
Outside the Vault, the Doctor asks Missy how he can save his friends when he is blind, saying “How can I save them when I’m lost to the dark?”