Featuring the first appearance of Mera! Aquaman and Aqualad meet Mera, former queen of a watery dimension. But when the usurpers of the throne come after her, it's up to Aquaman to protect the exiled beauty!
On patrol, Aquaman and Aqualad spy a runaway, abandoned ship, ablaze, on the horizon. Racing to clear the ship from the sea lanes, the pair are intercepted by giant pincers, formed from a nearby coral reef. Upon freeing themselves from the pincer's grip, the pincers dissolve. Turning back to the ship, they are startled to see a wave of water, shaped like a magnifying glass, hovering above the vessel. The sun's rays, focused through the enormous magnifying glass, ignite the ship's cargo, causing an explosion, spewing burning oil out across the waves. Aquaman and Aqualad spy a woman swimming away from the wreckage at unbelievable speed. Aquaman and Aqualad give chase. Just as Aquaman is about to lay hands on the woman, she rises up out of the sea in a water bubble. Suddenly, the bubble pops, dropping the woman into Aquaman's arms. The woman identifies herself as Queen Mera of Dimension Aqua. She had spied the crew abandoning ship, when a fire in it's cargo hold had burned out of control. Using her ability to control water, she had pulled Aquaman and Aqualad away from the ship with the pincers, while simultaneously creating the magnifying glass to speed up the ship's foregone destruction. Mera is in exile from her world, as a powerful usurper to the throne, Leron, has captured her kingdom. Mera fled to Aquaman's world through an inter-dimensional portal, created by Dimension Aqua's lead scientist, Xebel. Evidenced by the dissolution of the water bubble, Mera is at a loss to explain the sudden absence of her powers. Just then, five submarines come hurtling out of the ocean, borne aloft on water spouts. Aquaman, Aqualad and Mera are barely able to evade the ersatz missiles. As the assault ends, Leron appears, riding atop his own water spout. Before the heroes can react, Leron solidifies the water around them to a steel-hard consistency. He demands Aquaman give up the queen, or they will all remain imprisoned there forever.
Aquaman commands hundreds of fish to leap from the sea, buffeting Leron, over and over again, by a seemingly endless horde of marine life. His concentration broken, the solidified water holding Aquaman, Aqualad, and Mera returns to normal. The trio make good their escape while Leron is occupied. Instructing Aqualad & Mera to keep a watchful eye on Leron, Aquaman departs to garner aid. Aqualad and Mera spy Leron, along with three of his followers, re-entering Aquaman's world from Dimension Aqua. As Aquaman returns, Leron catches sight of the three heroes. He opens a swirling pit in the sea, around them. Before they can fall too far, Aquaman is able to plunge through the water walls, with Aqualad and Mera in tow, escaping back into the ocean. Aquaman charges Leron, boasting that Leron is no match for Aquaman's abilities. Leron strikes with an immense hard water scimitar, but Aquaman counters with an even harder water shield. Leron's scimitar shatters on impact. Aquaman then launches into the air on a hard water platform, buzzing Leron and his followers. At this point, Aquaman starts pelting Leron's group with giant hard water spheres, driving them off. The mystery behind Aquaman's newfound abilities is revealed to be Quisp, the magical water sprite from the secret sea. Aquaman has called on his friend to help even the odds against Leron, and his followers. Quisp offers to raise an army of water sprites to help Mera win back her kingdom. As Quisp departs to gather his forces, Leron trails him, camouflaged in the guise of a shark, albeit one composed entirely of hard water.
Leron ambushes Quisp, leaving the water sprite unconscious on the sea floor. Then, Leron comes for Aquaman, Aqualad, and Mera. As they attempt to flee to the mainland, Leron captures them within a large polymer bag. To their surprise, Leron drags them back to Dimension Aqua. There, they are imprisoned within a spherical coral cage. Leron calls for Xebel to be brought before him. Leron demands that Xebel give up the secret for controlling the inter-dimensional portal, or else the queen dies. Xebel is given a short time to mull over Leron's ultimatum. In that time, Aquaman summons octopi through the portal. The octopi first render the guard unconscious, then, using an anchor and it's chain, hurl the coral cage against a nearby wall, shattering it. Aquaman, Aqualad, and Mera escape back to Aquaman's world, through the portal. Accidentally cornering themselves in an underwater cavern, all seems lost as Leron, and his followers, closes in on them. Just as Leron and his men reach the mouth of the portal, Aquaman wipes a smudge of oil from Mera's arm. Suddenly her powers return, and she violently expels Leron, and his followers, from the cavern with a powerful wave. Aquaman, Aqualad and Mera make a run for it. Leron is hot on their trail. Spying an oil tanker on the horizon, Aquaman rises up to the surface, riding atop two swordfish. He commands the swordfish to pierce the tanker's hull, flooding the sea with oil. Swimming into the oil drenched waters, Leron and his men suddenly lose their water manipulating abilities. Aquaman realized that it was only after Mera had swam through the burning oil, released into the sea by the ship she destroyed, that she lost her abilities. He correctly surmised that wiping the oil from her body would restore her powers, just as immersing Leron in oil would erase his. Mera is confused, though, as it is lead, not oil, that is detrimental to her people. Aquaman explains that practically all refined oil has a high lead content. Mera takes Leron and his men into custody, returning to her kingdom through the portal. Quisp arrives too late to say goodbye, but Aquaman assures the water sprite that they will see Mera again.