10 Disturbing Video Game Twists That Came Out Of NOWHERE
3. Caroline Is In GLaDOS - Portal 2
As the cold and hilariously cruel antagonist of the first Portal game, GLaDOS was the perfect incarnation of just how callous a fully sentient AI could be.
And then the sequel came around, and revealed that the hider of cake and bringer of puzzles wasn't as robotic as we might have thought. Because Caroline - who was the secretary of the company that made GLaDOS - had her consciousness placed inside the insane machine, functioning as a way to (slightly) control her murderous impulses.
Now, while it isn't made clear if this act physically harms Caroline or merely copies her consciousness, unused audio clips have her tell Cave Johnson that she doesn't want to be part of the AI, which means that either way, the whole thing is still incredibly creepy.