Literature
Remember
Looking out into the world around her she realizes that she can never escape. Everyday she's locked up in her tower the world keeps moving, even though her world stays still. The tower is invisible, but she can see out. And the pain of seeing the rest of the world not missing her would kill her if she wasn't immortal. If they knew her pain they might think twice before they decided to keep her up hear.
They don't remember though, it happened so long ago. Even the people who keep her captive have forgotten. They probably think that she has died, but they forgot they gave her immortality. It was meant to be a gift, so that she could look over