Nessa has disappeared. Tarkleigh last saw her running to the Mud Flats. You must now search the surrounding areas for her.
When you find Nessa in the Mud Flats she has been transformed into a mermaid by the Brine King. You must now travel to the Brine King's Reef.
From the Western Forest, enter the Riverways, enter The Southern Forest (Act 6), and then search for The Cavern of Anger (Act 6). Inside the Cavern of Anger you will find The Black Flag. Search for the entrance to the Beacon. Use the The Black Flag"May the lubbers feel fear in their
nethers, and may our blades follow."
- Rot-tooth's Rallying Cry at the Beacon to summon Weylam Roth's ship, the Black Crest, which will take you to the reef.
After arriving at the Brine King's Reef, search for Nessa.
Quest Complete - You have defeated the Brine King and gained access to Act 7.