The Black Mirror episode 'Playtest' has one of the most terrifying, horror movie-like endings the show has ever seen. Black Mirror is a sci-fi, fantasy, horror anthology series that has a different premise each episode and is a collection of short stories. Most of the show's themes center around the unknown horrors that come with advanced technology. 'Playtest' is no exception and shows what could happen when experimenting with untested technology. Spoilers to follow.
'Playtest' has a ton of references to games and the gaming industry throughout the episode. Its main character—Cooper Redfield—even has the same last name as a popular character in another horror game series, Resident Evil. But what makes this episode scarier than a regular haunted house story is the twist at the end. Cooper is an American in London seeking adventure as a way to make memories before his worst fear comes true and he ends up like his deceased father who suffered from Alzheimer's disease and dementia. Rather than face his problems and talk to his mother, he runs away from home to get away from it all. He uses comedy as a way to deflect his emotions and as a coping mechanism.
Cooper desires to be a free bird and not have to get stuck taking care of another parent who's lost their mind. He is a thrill-seeker, and doesn't want to admit when he is scared. When his money gets stolen, he has to do odd jobs to get some cash for a plane ticket home. This is why he decides to test out a video game that is still not stable or open to the public. The game augments reality and provides a truly terrifying story by filling the location—a haunted mansion—with the player's subconscious fears.
If this alone was the premise of the story, it would already be one of the scariest episodes of Black Mirror. But it goes even further with the twist at the end of the episode. Throughout the episode, Cooper's subconscious fears are brought to life; like his high school bully, his love interest betraying him, and his fear of spiders. When Cooper uses his safe word 'stop' to have the game developers end the experiment, one of his biggest fears is explored—his fear of losing his memory like his dad.
It gets even weirder than that. Cooper 'wakes up' from the experiment and finally goes home to confront his mother. When he arrives back home, the game is still doing its job of projecting Cooper's fears into real life. His mother has succumbed to dementia and does not recognize him. It all starts to make sense when his mom says she needs to call 'Cooper' who is right in front of her. He hears the buzzing of a technological interference and the twist is revealed.
Before the experiment started, Cooper was warned not to have his cell phone on as it could interfere with the experiment, but Cooper has been tasked to take some pictures of the gaming equipment to sell to other companies and make more money at the suggestion of his love interest. So he turns his phone on. Cooper's mom has been constantly calling him throughout the episode, and when the gaming equipment is starting up, his mom calls him one last time causing the system to malfunction and fry Cooper's brain.
What makes it even more terrifying is when the viewer hears Cooper calling out 'mom' over and over again, and they realize this entire sequence happened inside Cooper's brain in less than a second. What makes the twist so terrifying is that Cooper's brain filled in the details of what might have happened in the game so quickly. The details were just things Cooper's brain remembered in the very recent past leading up to the event. These details are small things the conscious mind does not pick up on, but the brain stores in the memory.
The whole episode is sort of like Cooper's life flashing before his eyes. His past came back to haunt him, and his fears of the future were brought to the surface—causing him to have no choice but to confront them. Black Mirror has had some pretty crazy twists in the past, but this one takes the spot as most terrifying.
The moral of the story (other than to not always see technology as a good thing) is to confront the past (and call your mom). There is still so much the world does not know about the brain. It is a complex organ with so many fascinating functions. When the brain stops working, then the reality of that person goes with it. Brains are so powerful that Cooper didn't even know his reality was all in his head, which is what makes this episode so scary.