Brought to you by "Mommy Dead & Dearest," the HBO documentary on Gypsy Rose Blanchard:

"In the Disney movie Tangled, the girl's mother keeps her locked in a tower her whole life. In the end, Mother Gothel dies, because Rapunzel stands up to her and says she wants to leave the tower. But Tangled is a fairy tale, and real life isn't. Things don't end the same way in real life. I found that out the hard way."

... have your character identify with a character from a book or fairy tale and take inspiration for what to do next from said story, only to have it backfire horrifically.

(the documentary is pretty good, I recommend it).