Have you ever wondered if, just maybe, Percy actually had a twin sister? One that he never met. If so, then you are correct. This story is about a young girl named Pearl. She was Percy's twin sister, but because they were twins, their powers interacted with each other, making them way to strong together. So, the gods had to separate them. Pearl was raised on Olympus, knowing exactly who she was, while Percy was raised in New York, not knowing who he was.
Note: I have read other stories kinda like this, and I didn't like some of them and decided to make my own. Please read it!