Speak to Vishra just inside the zone and pick him up as a quest mercenary.
Approach the center barrier at -198, 5, -889 and it will drop.
Defeat Queen Dulseris with Vishra.
We recommend sending Vishra in to fight while you start out standing by one of the seashells.
Shortly into the fight you will see a message about the queen summoning protectors. Click on the three seashells quickly to bring the barriers back up, otherwise the Epic x4 protectors will join in the fight.
Click the gem at -98, 7, -866 to pick it up.
Return to Field Marshal Vishra in Scarstone to complete the quest.