In the Doctor Who episode "Extremis" we learn that

The Earth is simulated by a race of aliens, (refered later as "The Monks"). That this truth had been discovered centuries earlier and put in a book, The Veritas, written in a forgotten language that has just been translated

The Veritas contain informations on the limitations of the simulations, and can proove that people are simulated

Thus being said, the Monks have no interest in letting the Veritas exist in the simulation, actually they would get a much more representative simulation if the limitations of the simulation were kept secret.

Moreover, we see them directly influence the simulation, by attacking people. So why didn't they destroyed the Veritas centuries ago? Thus keeping the simulation more realistic.

Related question here.

  • 2
    I thought they did, but people kept bumping into the limitations themselves, such as the random number counters, so they were able to recreate the Veritas again and again. But I could be wrong; I'm planning on rewatching some episodes with friends in the weekend, so I'll get back to you.
    – Mr Lister
    Jun 2, 2017 at 10:35
  • 1
    There's always a lot of holes in DW. I mean, they'd get a much better simulation if they just made everyone use a different pseudorandomnumber seed, too. The Monks said that they've already killed the Doctor many times, so this was one of many simulations... perhaps in each they do different things to experiment, and this was the one where they included a "what happens if people find out they're simulated" test. Jun 2, 2017 at 11:58
  • @starpilostix I know that Dr Who often has plot holes. But this particular episode seems to be FULL of it. And I'm not sure if it's a plan by Moffat (we are missing informations to get a surprise reveal later on) or a key episode which is poorly written. I Just want to be sure I didn't miss anything
    – Edelk
    Jun 2, 2017 at 13:03
  • 1
    I was a bit disappointed with the follow-up episode, since they never mentioned it again, apart from the remark at the beginning that the Doctor had received an email. That was all. As if this episode hadn't really happened! Ehm, wait.
    – Mr Lister
    Jun 2, 2017 at 13:11
  • 1
    However they generate it, their simulation are near perfect and seemingly of all of history any errors that DO crop up are going to be hard to spot and track down, as long as they still lead to a similar-enough prediction of the present situation. (I still wonder whether the 'female Pope' thing was meant to be a clue, another 'historical error'... I know a secret female Pope was rumored IRL, but not IIRC, that PARTICULAR Pope) Jun 2, 2017 at 14:05

3 Answers 3


The Monks could be testing Veritas as a weapon.

If the Monks' goal is to eliminate humanity, then the simulations have shown that all that the Monks need to do is convince our species that we do not possess free will. Stage magicians have ways to influence a person's choice of random numbers. Perhaps the Monks have already developed similar techniques and were testing their effectiveness.


I saw it as a parallel to The Matrix

  1. You want as real a simulation as possible so you give up some control to the simulation itself
  2. Sooner or later the simulation has flaws, which participants notice

I saw Veritas as the parallel to the conundrum of The One. Sooner or later someone figures it out and sees through the false to the real. So Veritas wasn't something they could control, lest their simulation be less realistic than it needed to be. I mean, they let the simulation Doctor email the real one. That would seem to indicate they valued realism over security.


the monks wanted people to find out that it was a simulation as this would warn them about people who are actually smart enough to figure out that they are in a simulation and the monks would be able to see what they will do if they find the Veritas.

DOCTOR: Yes. Let's bring the story up to date, Bill. Imagine an alien life form of immense power and sophistication, and it wants to conquer the Earth. So it runs a simulation. A holographic simulation of all of Earth's history and every person alive on the surface. A practice Earth, to assess the abilities of the resident population. Especially the ones smart enough to realise that they are just simulants inside a great big computer game. BILL: But this is, this (knocks on the desk) This is real. I feel it.

  • Is there anything in the show to suggest that this is the case?
    – Mithical
    Jul 23, 2017 at 14:59
  • the doctor says it himself @mithrandir
    – HN17
    Oct 11, 2017 at 16:44

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.