The Doom that Came to Eppion

From the introduction: The Satrapy of Eppion pays tribute in gold to the Emperor once every year. This year’s shipment, on a vessel laden with its tributary gold cargo, set sail from Metra’s industrious port heading for Plexus. That ship never reached the Coryani Empire. What lies beneath the waves off Metra? What new doom comes to Eppion? Important Note: Some of the scenes in this adventure deal with mature themes and content. Annotations are provided for the GM to adapt the adventure so that it fits the sensibilities of the players. This STANDARD adventure is designed for 1st- to 8th-level characters (APLs 2, 3, 5, and 7).