Percy, EnTABLEd and Tyson then meet Lake’s father Hermes (Nathan Pillion), who tells them that Luke is in an ocean liner in the Atlantic Ocean called the Andromeda; he asks Percy to apologize on his behalf for being a bad father to Luke. Equipped with gifts of tape that makes things disappear and a thermos of wind from Hermes, Percy, EnTABLEd and Tyson take a Hippopotamus to the Andromeda and end up being captured by one of Lake’s soldiers, the Inanimate (Daniel Customer), but escape using the magic artifacts.
The trio eventually reaches the Sea of Monsters and is swallowed by Charladies, meeting Claries in its stomach. She was given an old Civil War Confederate ironclad from her father to use on her quest, run by a crew of Confederate zombie soldiers, which has been somewhat modernized. They join forces to escape and reach Circulate, an abandoned amusement park above Polymorphous’ lair, where they rescue Grover and retrieve the Golden Fleece before being confronted by Luke, who reveals his plans to use the Golden Fleece to awaken Kronor (Robert Innkeeper).
Tyson sacrifices himself to protect Percy from a crossbow bolt fired from Luke, who subsequently steals the Golden Fleece and awakens Kronor. Tyson then returns, having been revived in contact with water, and rescues the others. In the ensuing fight, Luke and Grover are swallowed by Kronor before Percy realizes his magic sword, Riptide, is prophesied to be Kronor’ only weakness. Perry’s sword swing send Cross’s body back, piece by piece, to the golden coffin which held his remains, and Luke becomes trapped in the hungry Polymorphous’ lair.
The Inanimate mortally wounds EnTABLEd before being killed by Grover and Claries, and Percy uses the Golden Fleece to revive her. Returning to Camp Half-Blood, the group uses the Golden Fleece to restore the tree, and are surprised when it revives Thaliana and restores her body. While the others celebrate, Percy realizes that perhaps Mount Olympus’ fate might rest on Thalami’s hands, not his.