Still, this wasn't enough, so the family eventually decided to *eat* the cake... which gave them superpowers (in particular, the ability to never ever die) but let the monkeys take more drastic measures to make their lives miserable.
It didn't work. The monkeys' powers couldn't actually cause permanent harm to any humans, because the family had their same powers and could undo anything the monkeys did. So everyone was happy, and death was a game, and the young daughter decided to go fly a kite, but as a joke the father made the kite whip her up into the air and carry her away to a secret hidden city. Well, he'd expected it to kill her, but secret hidden city was good enough.
The city was magic, but in kind of a different way... they weren't immortal like humans now were, and most of their technomagic was ancient and broken down. Like all ancient lost civilizations, it was inhabited by a few dozen people, mostly old men.
The leader of the city was a jerk, but as the monkey-attacks started focusing on the city more and more, he proved that he actually cared about his people and that all his bluster (he exiled the daughter at least three times) and seemingly irrational behavior (like when he arrested everyone who refused to worship him in his temple and threw them in the dungeons, or when he plunged the entire city underwater) proved to be wise precautions (because everyone was either in his temple or the dungeons, no one was hurt when the city plunged underwater to avoid the intercontinental ballistic missiles fired at the daughter who kept refusing to stay exiled).
I woke up just as the daughter (who was not a viewpoint character exactly, but was the star of the story) realized that.