All Hope Lost 
For three years, Percy Jackson has absent from the lives of his family and friends. To the world he was dead, but when the world needed him, he came back. With the possibility of hell on earth looming on the horizon, he turns to the people he trusts the most. His family. Racing against a very literal deadline, they search for a way to stop the gates of hell from opening, to keep the prophecy from ever being completed.
A war is coming, and it's going to take a sacrifice to win it.
Meanwhile, Percy battles within himself as he struggles to reconcile with what he did to survive. And when his actions are exposed to his family, they begin to wonder if they can trust him. They say when you can't trust anyone else, you can trust your family, but who do you turn to when you can't trust your own family?
A promise was made, and it's collection will be the tipping point of the war. This promise made in hell, a promise of life or death, is all it will take.
Hell is coming.
He's coming for Percy.