Ocean Master: Year of the Villain #1

Ocean Master returns to Erin Shaw to explain to her his reasons for leaving her and Tommy to fight for Atlantis. He details how he escaped from being imprisoned as an enemy of Atlantis, and how he discovered the Marine Marauder had been capturing Atlanteans outcasts and transforming them into into hybrid monsters. After defeating the Marine Marauder with the help of an Ocean Elemental, he frees her hybrids and establishes the City of Dagon where all Atlantean outcasts are welcome, if they accept Orm as their king.