A rash of criminal acts, perpetrated by a masked marauder, have drawn the attention of the Liquidator to Atlantis. Lord Ragnar, of the Atlantean Guard, requests that the Liquidator stay his relentless pursuit of evil, to give the Atlantean King, Aquaman, the opportunity to bring the marauder to justice himself. Upon receiving the news that the Liquidator has become involved in the manhunt, Aquaman collapses. Aqualad rushes his mentor to an Atlantean hospital. There, after long moments in a severe comatose state, the Sea King revives. With no memory of his collapse, Aquaman forcefully exits the hospital, intent on mustering his troops, and hunting down the marauder plaguing Atlantis. Aqualad races to join his mentor in the hunt, but Aquaman does not wait for his junior partner. Climbing atop his mount, Storm, Aquaman races off into the sea, leaving Aqualad far behind him. Aqualad, riding his own mount, Imp, pursues. Upon investigating the sounds of battle, Aqualad discovers that the Atlantean Guard has been ambushed by the marauder, and only Lord Ragnar is left to tell the tale. Aquaman arrives, still acting erratically. Aquaman demands to know why Ragnar is not wearing the golden helmet he awarded him for valor, and is instead sporting a silver helmet. No sooner has Ragnar responded to the King's inquiries than Aquaman collapses again. Aqualad and Lord Ragnar return the king to Atlantis, where he is left to recover, in his bedchamber. The Liquidator also arrives in Atlantis. Following the trail of evil has brought the Liquidator to Aquaman's very doorstep. Aqualad and Queen Mera block the Liquidator's path to the royal bedchamber. Suddenly, the doors burst open, and a, clearly, deranged Aquaman confirms the Liquidator's accusation that he is the marauder.
Aquaman blocks the Liquidator's initial attack, then flees the throne room. With Aquaman revealed as the marauder, Lord Ragnar commands the Atlantean Guard to detain their king at the gate. Aquaman is too strong, though. He overpowers the guards and escapes into the open sea. The Liquidator takes off in hot pursuit of the Atlantean Monarch. Refusing to believe that Aquaman could truly be a criminal, Aqualad and Mera set off in pursuit of the Sea King, as well. With the royal family out of Atlantis, Lord Ragnar takes this opportunity to seize the throne, and surprisingly, he very quickly garners the support of the Atlantean citizens. Far away from Atlantis, the Liquidator has cornered Aquaman. Aquaman summons the denizens of the sea to aid him, but they refuse to answer his telepathic commands. As the Liquidator moves in for the kill, he is struck from behind by Aqualad, who rams his mount, Imp, hard into the Liquidator's back. The Liquidator catches Aqualad and prepares to punish the young hero for his interference. Aqualad cries out to Aquaman for assistance, but Aquaman, instead, flees while the Liquidator is so occupied. Suddenly,the Sea King doubles back and rescues his junior partner. They quickly put some distance between themselves and the Liquidator, eventually, finding a suitable hiding place. Under cover, the two heroes bear witness to a meeting between Lord Ragnar and the Liquidator.
Lord Ragnar warns the Liquidator that Queen Mera has sided with her husband. The Liquidator vows to punish all who stand with the Atlantean Monarch. Lord Ragnar, as the new King of Atlantis, pledges to use all his power to aid the Liquidator in slaying the royal family. Aquaman comes to the realization that it is Ragnar who has been the masked marauder of Atlantis all along. Ragnor has, in some fashion, transferred his own evil thoughts to Aquaman, drawing the Liquidator to the king and away from Ragnar. In some way, Ragnar has also shielded his evil from the LIquidator so as not to face it's dread punishment. Mera appears and closes with the Liquidator. Aquaman breaks cover and races to protect his wife. He is suddenly overcome with waves of evil thoughts. He attacks the Liquidator, then spins at incredible speed, churning the ocean water up into a spinning cylinder, that protects Aquaman from the Liquidator's lashes. Lord Ragnar abducts Mera, drawing her away from the battle, so that she cannot aid her husband with her water manipulating powers. Aqualad pursues the treasonous Lord Ragnar. Aqualad instructs his walrus companion, Tusky, to steal the helmet from Lord Ragnar's head. With Lord Ragnar's helmet removed, Aquaman immediately regains his senses, and the Liquidator finally sees the true evil in Lord Ragnar. Fearing the Liquidator's punishment, Lord Ragnar fires his weapon at the canyon walls all around them, burying the Liquidator under tons of rock and debris. Aquaman, however, is not so easily deterred. He evades Lord Ragnar's weapon's fire, and summons an armada of sharks that cut off Lord Ragnar's escape route, before descending on the Atlantean traitor. Justice served, Aquaman sets about freeing the Liquidator, before returning, with his family, to Atlantis.