The royal family of Atlantis are enjoying some down time, outside the city's walls. Aqualad, his sea horse, Imp, Tusky, a walrus, and the infant, Arthur, Jr., are playfully roughhousing, to Aquaman's great amusement, and Mera's great concern. Mera's fears come to fruition when Arthur, Jr.'s life is suddenly placed in jeopardy. Too forcefully bucked from Imp's back, the tiny heir of Atlantis is sent hurtling towards an outcropping of rocks. Before anyone can react, Arthur, Jr. is saved by Aquaman's evil half-brother, the Ocean Master. Aquaman and Aqualad demand Ocean Master release the Prince of Atlantis. Ocean Master responds by callously tossing the baby away. Mera projects a hard water hand to catch her son. Furious, it's all Aquaman can do to stay his hand from striking his half-brother. The final straw breaks, when Ocean Master taunts the King of the Seas, by firing a harpoon at Iron Jaws, a 600 year old turtle. For the first time, Aquaman violently attacks the Ocean Master. The two are locked in mortal combat when, suddenly, the ocean seems to explode all around them. It takes several moments for the "First Family of The Seas" to recover. When they do, two things become readily apparent. First, the Ocean Master is gone. Second, and, by far, more disturbing, there are suddenly pockets of evaporated ocean water surrounding them. Aquaman has little time to investigate the strange phenomena, as just over the horizon appears an immense scorpion shaped submersible. It is the signature ship of the the Scavenger.
The Scavenger boasts responsibility for the ocean's continuing dissolution. He seeks a device, called a "time decelerator". The sea will die if it is not given to him. Enraged, Aquaman attacks the scorpion ship, but it's hull proves impregnable to his blows. Aquaman summons a bull whale, to ram the Scavenger's ship, over and over. Still the scorpion ship remains unscathed. Aquaman summons torpedo rays that release 600,000 volts of electricity through the Scavenger's submersible, to no effect. Aquaman angrily informs the Scavenger that he has no knowledge of the time decelerator. The Scavengers refuses to believe Aquaman's "lies" The device will bestow immortality upon it's possessor, and the Scavenger means to have it. Just then, the manta ship of the Ocean Master descends on the Scavenger's scorpion ship. Ocean Master fires a heat seeking torpedo on the Scavenger's ship, but the scorpion ship merely ices over, thwarting the missile's guidance system. Ocean Master fouls the waters with colored dye to conceal his movements from the Scavenger. Under cover, the Ocean Master stealthily moves his manta ship into an attack position. Steering by sonar alone, though, gives the Ocean Master no warning that his ship is moving into a large pocket of evaporated ocean. No longer buoyed by the sea, Ocean Master's manta ship crashes to the sea floor. Laying prone on the jagged rocks, Ocean Master is in no condition to defend himself from Aquaman and Aqualad, who rapidly close on his position.
Rather than attacking, Aquaman enlists the Ocean Master's aid in opposing the Scavenger. The three split up to ferret out the Scavenger's location. With the surrounding ocean waters evaporated for miles, Aquaman and Aqualad are forced to trade in their sea mounts, Storm and Imp, for a pair of sea crocodiles, which can speedily scamper across the sea floor. Unbeknownst to them, The Scavenger has located Mera and Arthur, Jr., and taken them hostage. The Scavenger reveals his hostages to Aquaman, demanding the time decelerator, in return for their continued well-being. With the seas now an arid wasteland, The Scavenger smugly believes that Aquaman is powerless to enlist aid against him. Aquaman is quick to prove him wrong, as an army of giant squid, octopi, and sea snakes come slithering across the sea floor, to assail the scorpion ship. Outside the evaporated pocket, giant manta rays plummet through the mantle of ocean water to dive bomb the Scavenger. Aquaman joins the fray, desperately trying to pry open a hatch to gain entry into the scorpion ship. The assault is a complete failure, and Aquaman's marine denizens slink back across the pocket, returning to the sea. Aquaman and Aqualad, too, are greatly weakened from their prolonged absence from the sea. The Ocean Master arrives with news that he has located the time decelerator. Ocean Master leads the Scavenger to a nearby cave. The scorpion ship's sensors do, indeed. detect the presence of the time decelerator. As the scorpion ship descends into the cavern, Ocean Master prepares to detonate a series of explosives he has planted within the cave. Aquaman quickly stops the Ocean Master, before he can kill the Sea King's family, still on board the Scavenger's ship. Aquaman catches up with the Scavenger, who has exited the safety of his scorpion ship, but he's too late to keep the villain from activating the time decelerator. A viscous fight ensues. Just when the Scavenger is about to gain the upper hand, he suddenly, rapidly, regresses back into infancy, then into nothingness. Aquaman detonates Ocean Master's booby trap, destroying the scorpion ship and the time decelerator. With the scorpion ship destroyed, the seas return to normal. While the threat from the Scavenger has ended, Ocean Master has escaped, and will, no doubt, challenge Aquaman another day.