When Percy is no longer a son of Poseidon, but a son of Chaos called Omega, he finds that he has a sister named Jessica who, along with her friends, gets into the army of Chaos. Percy has been betrayed by his fellow campers and doesn't wish Jessica to go to Camp Half-Blood, so he convinces her to become a daughter of Chaos. One day, Chaos gives them a mission that involves saving Olympus, Percy grudgingly agrees. Because every member of the army has to keep their hood on, will Annabeth and Matthew, another son of Poseidon, along with the whole camp and Olympus, find out who Percy and his army are? Will there be a fresh start or will everyone's past determine the future?