It's safe to say that Black Mirror isn't the nicest of shows. Since it debuted in 2011, the show has been spitting out episodes that provoked reactions ranging from "wow, that's dark," to "I feel physically ill and I need to lie down."

But looking back on the show's nineteen episodes, it's hard to pinpoint which moments, exactly, are the hardest to watch. Which moments are the most likely to stick in your head for the rest of your life? Which moments will re-emerge into your thoughts one night years in the future, and keep you laying in bed for hours, parsing through all the little implications and horrifying details?

There's a lot to pick from, but these are the ones that surpassed all expectations and went horribly dark, even by Black Mirror's standards/

(Warning: Spoilers ahead.)