Cronus, who has assembled a vast army of titans, wants to seize and destroy the sacred Olympus. To help him, he summoned a mighty giant—Typhon. The gods go into battle against this terrible foe, leaving their home unprotected. And only Percy Jackson—the only one who has figured out Cronus’s military trick—steps forward. Together with his friends, the half-bloods, he stands to defend Olympus. Will they manage to repel the attacks of the monsters, or will the defenders have to die in an unequal fight? They can hope only for a miracle—and for the help of those gods who, for now, prefer not to take part in the battle.