Leaving Atlantis, Aquaman and Aqualad head out on patrol. Aqualad notices an anchor, from an old shipwreck, hanging down, instead of winched up tight, like normal. Pointing it out to Aquaman, he is stunned when Aquaman orders him back to Atlantis, and abruptly departs. Releasing that particular anchor is a signal to Aquaman, from American Intelligence agents, to meet at a secret rendezvous spot. Once passwords are exchanged, Aquaman meets with an agent known only as "The Tall Man". The Tall Man informs Aquaman of a plot, by the terrorist organization O.G.R.E., to erect a barrier around the United Nations building, in New York City. With the delegates of the nations of the world all held hostage, O.G.R.E will then demand a ransom, from each delegate's native country. The weapon that will create this barrier has one weakness. It cannot penetrate water. The Tall Man proposes that Aquaman erect a water barrier around Untied Nations headquarters before O.G.R.E. can get their shield up. To that end, Aquaman, approaching from the East River, cuts a channel around the entire U.N. building, then breaks through to pressurized water veins in Manhattan's bedrock. Released from the island's sub-strata, the pressurized water rapidly erupts up through the channels, breaking through the pavement, on the streets above. The water jets completely surround the U.N. Building, forming a fast moving, high pressure, water dome cascading over the structure. With a weapon given to him by the Tall Man, Aquaman is able to accelerate the speed of the water flowing through the "dome", making it even more impenetrable. With the barrier erected, agents of O.G.R.E., already inside the U.N. building, hold the delegates hostage, at gun point. The "Tall Man" is revealed to be Krako, a high ranking member of O.G.R.E. Krako underwent reconstructive surgery to make himself look like the Tall Man. O.G.R.E. had no device for erecting a barrier around the U.N. building. The plan, all along, had been to dupe Aquaman into creating the barrier for them. Aquaman is arrested by government agents, and learns the truth about the "Tall Man", he received his orders from. Crestfallen, the monarch of Atlantis breaks free from custody, and escapes into the streets of New York.
Outside the U.N Building, the US Army makes their first attempt to penetrate the barrier. A manned rocket shell is fired into the barrier. It careens off, hurtling into orbit. The soldier inside the capsule ejects out, before it reaches escape velocity. The Army's second attempt, a diamond tipped drill, also proves futile. Aquaman, wearing civilian garb, and using the alias "Joe Doakes", turns up onboard a tour boat, passing by the U.N. building. Suddenly, a young boy falls over board. Aquaman rescues the boy, but is revealed to the O.G.R.E. agents hunting him. Aquaman flees from the O.G.R.E. agents, only to run headlong into agents of the U.S. government, who are also in pursuit of him. Aquaman climbs the ship's funnel and leaps for the water "dome", surrounding the U.N. building. Behind him, a furious gun fight ensues between the government agents and the men from O.G.R.E. Aquaman hits the dome and is rapidly carried up by the water's momentum. Reaching the apex of the "dome", Aquaman is shot, like a bullet, across Manhattan Island, landing on the Statue of Liberty, on nearby Ellis Island. Aquaman, however, has failed to elude his pursuers. O.G.R.E. agents, patrolling the waters, spot Aquaman on the Torch of Liberty, and blast him with high pressure water cannons.
Aquaman swims down the cannon streams. An O.G.R.E. agent, stationed inside the Statue of Liberty's head, shoots Aquaman, on his way down. Aquaman plummets into the rive waters. The O.G.R.E agents hurl explosives into the water, from their boat, to finish Aquaman off. As police boats approach, the O.G.R.E. agents flee the scene. With the US Army racking up yet another failure in penetrating the barrier, the nations of the world cave in to O.G.R.E.'s demands, and make arrangements to pay the ransom. Disguised again as "Joe Doakes", Aquaman has made his way back to Manhattan Island. He witnesses an O.G.R.E. tank coming up from a subway station. Before the tank crew can get a bead on him, Aquaman escapes down a man hole. O.G.R.E has actually flooded the sewers, to close that avenue of approach off to the authorities. That act, though, actually aids Aquaman in reaching the U.N. building, unseen. The tank crew is just taking possession of the ransom money, when Aquaman exits from another man hole, and takes them by surprise. He quickly beats down the tank crew, and dodges when the tank fires upon him. The tank's cannon has the power to penetrate the water barrier. The missed shot has, momentarily, opened a hole in the "dome". Aquaman throws the ransom money, through it, then dives in himself before the water curtain reseals. Inside United Nations headquarters, Aquaman immediately comes under fire from the agents of O.G.R.E. He is rescued by the real Tall Man, who guns down all the opposition. The Tall Man, operating on an anonymous tip, had already been stashed inside the U.N. building, in anticipation of a threat from O.G.R.E. Outside the U.N. Building, Mera arrives, and uses her power to control and manipulate water, to turn the water of the "dome" hard, but brittle. It instantly collapses. An Army fighter plane bombs the O.G.R.E tank. The Tall Man rounds up the rest of O.G.R.E.'s agents, and reveals that it was he who had contacted Mera for assistance. Aquaman is cleared of all charges, and told to remain vigilant, for O.G.R.E. is still out there, and this is far from over.