The Greek and Roman demigods will have to cooperate in order to defeat the giants released by the Earth Mother, Gaea. Then they will have to sail together to the ancient land--Greece itself--to find the Doors of Death--
Demigod Percy Jackson, still with no memory, and his new friends from Camp Jupiter, Hazel and Frank, go on a quest to free Death, but their bigger task is to unite the Greek and Roman camps so that the Prophecy of Seven can be fulfilled.
Everywhere Gray and Barkley swim, fish are whispering of a growing threat, of a shark named Finnivus who will eat anything or anyone, and won't stop until he has seized control of the entire ocean. Finnivus has an armada of vicious battle sharks to help him expand his empire, and Gray realizes that it's up to him to save the Big Blue. But first he must train with Takiza, the wise and mysterious fighting fish who has promised to teach his young apprentice...
Gray and his alliance of peaceful shivers, Riptide, Coral, and AuzyAuzy, have beaten the bloodthirsty emperor Finnivus and his vicious Indi Shiver armada to smithereens, sending them swimming as fast as they can retreat. But there's no time to party. Finnivus may have been humiliated, but he's still out for revenge. This is the ruler who feasts on the heads of every shark he conquers, after all.
Gray is already bigger than all the other sharks in his clan, or shiver. He can't stop growing, and when his hunger gets him into trouble, he's banished from the reef. Luckily his best friend Barkley comes with him ... but their hunt for food forces them to journey deep into the dangerous Big Blue.