Sixteen-year-old Thomas wakes up with no memory in the middle of a maze and realizes he must work with the community in which he finds himself if he is to escape.

Percy hurries to Camp Half-Blood after his high school is invaded by demonic cheerleaders, and joins his demigod friends on a quest through the Labyrinth, while the war between the Olympians and the evil Titan lord Kronos draws near.

Athena's arrogance throws a wrench into her plans to improve King Minos's labyrinth.