After a sea battle between the Olympians and the Titans, the Olympians find themselves shipwrecked on an island, and when Uranus' stars falls into the ocean, a dangerous wave of bubbles heads towards the island.
When Zeus, Hades, and Poseidon continue on a new quest in the search for the Helm of Darkness, they discover many things in the Underworld that Hades does not fear except a giant three-headed dog.