Percy Jackson was betrayed. Betrayed by all he knew. Punished by the Olympians for a crime he didn't commit. He was thrown into the abyss but the creator of universe, Chaos, helped him to have a place in his immortal army.

When the world is in danger again, from something more dangerous than a titan, or even worse than Gaea, the gods find that they need more help than they have, but Artemis has help. The Blessed of Chaos, subject to an ancient prophecy, are back, but they are different than they were a few years ago, and they only trust a few people.