Percy Jackson has a twin sister. What happens if she was taken to Olympus after she was born and raised there for seven years and then gets sent down to Camp Half-Blood? What happens when she gets a mysterious letter on her eleventh birthday by owl? Read to find out. Marauders Era Disclaimer- All rights go to JK Rowling and Rick Riordan exept for Pearl and any plot changes that come with her and any other OCs that I may add.