The city of Atlantis, once home to one of the world's most advanced civilizations, is now a sunken kingdom ruled by the greedy King Orm. With a vast army at his disposal, Orm plans to conquer both the other ocean kingdoms and the surface world. Standing in his way is Aquaman, half-human, half-Atlantean, and true heir to the throne. With the help of Princess Mera, Aquaman must retrieve the legendary Trident of Atlan and accept his destiny as protector of the depths.