The tides are rising... and so is something far darker than the bottom of the sea.
When a shadowy reflection of Percy Jackson emerges from the depths, wielding the ocean and monsters with terrifying precision, Camp Half-Blood faces a threat like no other. The real Percy is trapped in the inky waters of a creek that's more than it seems, tangled in shadows and haunted by his own fears. As friends fight to save him, Percy must confront not just a mirror of himself, but the dark possibilities that lie within.
In a story of choice, power, and the weight of what could be, one hero will discover that sometimes the greatest battles aren't against monsters... but against yourself.