Mer is another world. Most of the planet's surface is water, "The Twenty Seas" where there are creatures such as: Monkey-Birds and the Levithan. On Mer, Octopon was once a great city ruled by Primus, Primus was captured by the evil pirate Bloth, captain of the most feared pirate ship "Maelstrom" (who is after the Thirteen Treasures of Rule) and wiped out Primus's fleet, killed every heir to the throne of Octopon. But several of Primus's captains escaped with the treasures. 17 years later, Ren, a young teenager raised by a lighthouse keeper, learns he is the son of Primus and heir to the throne of Octopon. Joined by his companions: Niddler, loyal and cowardly Monkey-Bird, Ioz, a former pirate, Tula, a young ecomancer with the power to control nature and Zoolie, also a former pirate. Ren and his companions embarks on a quest as they travel across Mer in search of the Thirteen Treasures of Rule, where Bloth bids to take possession of the Thirteen Treasures of Rule and control "The Dark Water" tar-like water which swallow anything in it's path and engulf every island on Mer and destroy the world. By finding the treasures, only Ren and his companions can save the world from destruction.