We Hold Back the Void

Annabeth, being recruited by Chaos, leaves behind Percy to protect the universe as part of the Wings of Chaos. She must face the rising threat of Order, who lurks in the far reaches of space. But not is all as it seems, for a far more ancient threat is pushing in from the void. The army of Chaos faces its biggest threat, one even a Daughter of Athena might be outmatched by.