The Titans are stirring, and only Percy Jackson and the Olympians can stop them from destroying the world. Zeus, the King of the Gods, has been captured, and the Titans' only hope is to free Cronus, the most powerful Titan of all, from his thousand-year-long sleep.
Percy, Annabeth, and the rest of the demigods must travel to the Underworld and Tartarus, the prison of the Titans, to rescue Zeus and stop the Titans' plans. Along the way, they will face dangerous monsters, powerful gods, and the wrath of the Titans themselves.
But with the help of their friends, their courage, and their determination, Percy and the Olympians may just be able to save the world once again.