In the California home of millionaire Eliot Harlansan, a dire prediction is foretold by two agents of the terrorist organization, O.G.R.E. The sunken city of Atlantis will one day rise. When it does, California will take it's place at the bottom of the ocean. Harlanson is beside himself with fear that he could, possibly, lose his beautiful home. The men from O.G.R.E. convince Harlanson that the only way to save his house, and California, is to buy an atomic bomb and drop it on Atlantis. Harlanson agrees to do this. To ensure that Aquaman will be in Atlantis when the bomb drops, O.G.R.E. engages the services of the Black Manta. O.G.R.E. equips the Black Manta with a new weapon to use against Aquaman. O.G.R.E.'s intent is to keep Aquaman too distracted, in combat with the Black Manta, to prevent his death, and the destruction of Atlantis, from Harlanson's bomb. It takes Harlanson two weeks to procure an atomic bomb. In Florida, he boards his personal submarine, outfitted with the nuclear warhead, and sails for Atlantis. Outside the great domed city, the Black Manta, brandishing the weapon provided him by O.G.R.E., challenges Aquaman to face him. Aquaman telepathically summons an army of fish to assault the Black Manta. O.G.R.E.'s weapon disrupts brain waves, and with it, the Black Manta is able to scramble Aquaman's telepathic commands. Aquaman's fish army scatter in all directions. The Black Manta gathers his men and prepares to take Atlantis by force. Aquaman leaves the security of the city dome, to confront the Black Manta, personally. Unbeknownst to either combatant, Harlanson's submarine is closing fast on Atlantis.
With focused concentration, Aquaman is able to resist the effects of O.G.R.E.'s weapon, long enough to beat the Black Manta into submission. Aqualad and the Atlantean Guard deal with the Black Manta's men. Aquaman beats information about O.G.R.E."s involvement out of the Black Manta. Ordering Aqualad to guard the Black Manta, Aquaman begins patrolling the Atlantean perimeter, in ever widening circles. Searching for any signs of suspicious activity that might reveal O.G.R.E.'s intentions, Aquaman sees Harlanson's submarine en route to Atlantis. Not taking any chances, Aquaman summons a giant squid, and commands it to halt the submarine's approach. In a panic, and desperate to save his million dollar home, Harlanson releases the bomb on Atlantis. Horrified, the submarine commander informs Harlanson that, in the squid's grip, their vessel has been becalmed. They can't escape and they're too close to Atlantis. When the bomb hits, they'll all die. Harlanson breaks down. Aquaman races to intercept the bomb before it can impact the sea floor, but he is too far away. In horror, he watches the bomb strike the ocean bottom, bounce twice, then settle... without detonating. Harlanson's atomic bomb is a dud. Harlanson is enraged to find out he was sold defective merchandise and vows to rectify the matter.
Aquaman and Aqualad turn over O.G.R.E.s weapon to the US Governement. The King of the Sea is informed that government agents have already arrested the O.G.R.E. agents, who enlisted Harlanson's aid in destroying Atlantis. Information, garnered from those O.G.R.E. agents, allowed US Armed Forces to locate O.G.R.E.'s secret base, and dismantle the entire terrorist organization. Aware that O.G.R.E agents had reached out to Harlanson, a government agent, one Honey James, was sent to infiltrate the millionaire's life. Her information on Harlanson's movements and activities allowed the US Government to substitute an inert weapon, in place of the atomic bomb, with Harlanson none the wiser. Considered to be merely a dupe for the terrorist organization, Harlanson is allowed to return to his California home, astonishingly, without penalty. Aquaman, too, lets the Black Manta go free, feeling that his role as O.G.R.E.'s puppet was punishment enough to the villain's ego.