Percy Jackson, a young demigod, leads the defense of New York City when the Titan Kronos launches a massive attack. As the gods are busy fighting another powerful monster, Percy and his friends must protect Olympus from being destroyed.
During the battle, Percy faces dangerous enemies, betrayal, and difficult choices linked to an ancient prophecy about his 16th birthday. In the final fight, he confronts Kronos and helps save Olympus, changing the fate of gods and demigods forever.