Black Manta, Queen Vassa, and the Brain team up to destroy Aquaman. Vassa goes to keep Aquaman busy by destorying his emergency relay system, but retreats after her missile attack is repelled and her merman followers beaten off.
Meanwhile, Black Manta uses gas bubbles that burst into flame to try to penetrate the dome of Atlantis, but Aquaman is able to return Black Manta's own shots with help from a group of dolphins.
Trailing the fleeing Black Manta, Aquaman and Aqualad find where the three villains are hiding out. When Aquaman tries to sneak up on them he's blasted unconcious by the Brain and brought aboard the villain's submarine. The Brain tries to encase Aquaman in a rock of solid salt, but Aquaman calls for help from a whale that smashes a hole in the sub. He manages to punch his way out of his cage and escape the sinking Brain sub. With the Brain sub crippled the villains turn on each other; Black Manta blows up the Brain sub and Vassa attacks Black Manta before fleeing herself.