Though Atlantis sits nowhere near any fault lines, it, nonetheless. is at the epicenter of a massive seaquake, that does untold damage to the city. After assuring his people that Atlantis will be rebuilt, stronger then ever, Aquaman sets off for, essentially, a "coral quarry", to collect the necessary raw materials to rebuild. With him are his wife, Mera, their infant son, Arthur, Jr., and Aqualad. While in the canyon, the royal family of Atlantis are suddenly beset by a "stampede" of ocean going sea life. Whatever has spooked the fish, bearing down on them, has terrified them all so deeply, that they resist Aquaman's telepathic orders to turn back. Arthur, Jr., who had wandered off while the adult heroes collected supplies, finds himself in the direct path of the fish horde. Aquaman orders the fish to turn away, over and over, to no avail. Horribly, Arthur Jr. is overwhelmed and swept from view. The royal family is griefstricken and in shock at the sudden loss. Then, Topo, an octopus, lifts Arthur, Jr. up. At the last second, Aquaman's cephalopod companion had rescued the infant heir to Atlantis. On their sea mounts, Storm and Imp, Aquaman and Aqualad scour the canyon to determine the cause of the fish stampede. Aqualad's mount, Imp, is suddenly spooked by the appearance of an enormous eye, peering out at the two riders, from within the coral canyon. Aquaman is skeptical as to what Aqualad thinks he saw, but then the sea floor is violently rocked by the emergence of a giant hand. The hand grabs Aquaman, and lifts him up above the ocean's surface. Held fast in the incredible grip of the hand, Aquaman is unable to wrest himself free. The hand holds Aquaman there, high above the waves. Aquaman has one hour to escape and return to the sea, or else he will die from dehydration. The countdown has begun.
Aquaman summons a pod of whales. Aqualad fastens rope around the whale's tails, and around the giant forearm. The whales pull mightily, but the rope snaps before they can drag the arm below the waves. Aqualad leaps onto the giant hand, and attempts to break it's grip on Aquaman, but proves too weak to prevail. Mera creates a giant hard water hand, and uses her construct to try to pull the living hand into the sea. She, too, fails. As the hour draws to a close, Aquaman loses consciousness. Inexplicably, the giant hand, suddenly, releases him. The hand pulls back down below the water's surface, and down, again, under the sea floor. The royal family returns to Atantis, and discover that a recently opened fissure has unearthed a heretofore unknown, ancient part of the underwater city. Within the fissure, are the remnants of the ancient laboratory of Dr. Tryton. Dr. Tryton was the ancient Atlantean scientist/engineer, who designed and erected the Atlantean dome. Aquaman picks up a crystal rod resting on one of the lab tables. The rod channels the holder's natural body energy, releasing it in bolts of devastating power. Recognizing the name, "Dr. Tryton", Aquaman pays a visit to the Atlantean library's archives. Therein he finds scrolls detailing Atlantis's last days, as a surface city. Increasingly worse earthquakes and tidal waves were plaguing Atlantis. The city was on the brink of destruction. Dr. Tryton conceived of a protective dome, that could be erected around the city, saving it from ruin. Time was short, though. Atlantis would never be able to muster the manpower needed to erect the dome in time to save the city from the next series of quakes and tidal waves. Dr. Tryton ingested a growth formula that transformed him into a giant. His strength and colossal size allowed him to construct and erect the dome alone. Tragically, the earthquake that sank Atlantis also buried, and entombed, Dr. Tryton, underneath the fabled city. Aquaman realizes that, impossibly, Dr Tryton has survived. It is his stirrings beneath Atlantis that were responsible for the recent destruction. His presence that had terrified the fish in the canyon. Taking up the crystal rod, Aquaman returns, alone, to the coral canyon. Entering the cavern where Aqualad had spied the eye, Aquaman descends, ever deeper, in search of Dr. Tryton. Suddenly, the gigantic hand bursts through the cavern wall, blindly groping about for the Sea King. Aquaman blasts the hand with the crystal rod, but is too slow to escape a second hand. Held again in the giant's grasp, Aquaman is hurled down a hole in the cavern floor. Embedded in the sea floor, at the bottom of the hole, Aquaman discovers an atomic warhead. A second opening in the coral cavern wall is evidence of where the missile came through. Aquaman has little time to ponder the situation, for, suddenly, the manta-shaped submarine of the Ocean Master comes crashing through the canyon wall.
The Ocean Master had altered the missile's trajectory by remote control, but had been unable to track it down until now. Now that he has recovered the warhead, he intends to use it to black mail the United States. Aquaman informs the Ocean Master that this type of missile is designed to detonate if stolen, and that they are in terrible danger. Ocean Master scoffs at the idea, blinds Aquaman with a black light ray, then fastens a towing hook from his submarine to the missile. Aquaman snaps the tow chain with a blast from the crystal rod. Ocean Master fires a volley of miniature trident projectiles from his belt. Aquaman uses the crystal rod to incinerate the majority of them, then bats the last one away. He is finally able to convince the Ocean Master to allow him to disarm the warhead, before Ocean Master takes it. Aquaman reasons that Ocean Master's manta ship is the best bet for transporting the missile away from Atlantis. Just as he prepares to take Ocean Master down, the villainous marauder blasts him with a sonic pistol. Aquaman is revived by Aqualad, and the two set off for Ocean Master's manta ship. Ocean Master is just about to escape, when the monstrous form of Dr. Tryton explodes from the sea floor, and grabs the manta ship in his unbreakable grip. Gone is the learned man who was once Atlantis's greatest scientist. Whether from the long centuries of imprisonment, or the mutative effects of the growth serum, Dr. Tryton has been reduced to a raging, bestial ogre. Wrenching the missile away from Ocean Master's manta ship, Dr. Tryton begins crushing the submarine's hull. Aquaman again blasts Dr. Tryton with the crystal rod. Dr. Tryton releases Ocean Master's vessel. With the missile still held in his grip, Dr. Tryton leaps into a deep ocean chasm. There is a sudden flash of light. Aquaman hurriedly ushers Aqualad into cover. The warhead has detonated. Whether purposeful or not, Dr. Tryton has, once again, saved Atlantis from destruction. Though his scheme is thwarted, the Ocean Master escapes, to plague Aquaman another day.