10 Traumatic Doctor Who Facts You'll Wish You Hadn't Heard

Simulation theory has been a topic of discussion on various corners of the internet for years now, so it’s surprising it took Doctor Who so long to get around to using it for an episode.

But when it eventually showed up in Series 10’s Extremis, it did not disappoint.

Steven Moffat’s script really leans into the psychological horror of discovering you live in a simulation, incorporating more references to (and depictions of) suicide than most people would think possible in a prime-time BBC drama.

What’s more, he really sells that these simulations aren’t just two-dimensional copies of the “real” characters – they’re in many ways sentient in their own right, feeling both the physical pain and the existential dread of the situation they find themselves in.

Which makes it all the more grim when you realise that this isn’t the only time the Monks have run a version of this simulation.

In fact, they've been creating full, realised copies of our world again and again and again, repeatedly putting billions upon billions of simulated humans through the same terrifying experience of realising they're in a game, before being “switched off.”

Even the Doctor has died multiple times over, as the Monks coldly inform him towards the end of the episode. Killing the Doctor once is a huge feat, so to do it on repeat takes a frightening level of power.