Chapter 1: Menace of the Man-Fish
Doctor Deering shows Aquaman and Aqualad his new invention: a machine that can scavenge the ocean floor for shipwrecks, or drill into undersea mountains for ore and oil, or suck up the vegetation from the ocean floor. He's quite proud of the machine, but that's not all. He's also trying to perfect a process by which normal humans can breath underwater.
As he's working in his lab, an explosion occurs which turns him into a water-breather. He is shocked by his sudden reversal of fortune, because he cannot do his scientific work in the ocean. Aquaman fetches another doctor, who uses Deering's machine to examine him. The doctor pronounces the transformation permanent. Aquaman and Aqualad try to make Deering comfortable, but his mind snaps and he vows to make the oceans fit for human habitation.
And so Deering uses his marvelous machine on land, ripping up skyscrapers...
Chapter 2: The Underwater Puppets
The police can't stop Deering or his machine. Deering steals skyscrapers to place on the ocean floor, and makes his own metropolis to live in. But it's still missing a vital element: people. He attacks an ocean liner, intending to bring the people on board down with him, but Aquaman and Aqualad save them in time. In turn, Deering captures Aquaman and Aqualad, and forces them to be his first two citizens, with the help of his machine.
Chapter 3: The Water Breathers of Sunken City
As they stand in Deering's undersea city, a giant pair of scissors attack them. Aquaman and Aqualad plead with Deering to free them, but he just runs into his machine. But all the scissors do it cut the pair loose. It's Mera, come to save the day! She ties up the machine in hard water bonds, immobilizing it. But Deering's machine is very powerful, and breaks free.
They battle, and come to a stalemate. So Deering goes again to get people for his city. Mera protects the people, and Aquaman comes up with a plan. They convince Deering to return to his city, and it is full of people. They are from Mera's world, and a ruse to trick Deering out of his machine.
But Deering has a remote control, and traps Aquaman and Aqualad. Unfortunately for Deering, at that moment his water-breathing malady starts to wear off. Aquaman calls in electric eels to short circuit the control, and they save Deering. Aqualad uses the machine to return the sky-scrapers to the surface city.
I don't really like the cover to this one. Aqualad looks okay, but Aquaman has an odd expression on his face that makes him look old, and his legs are miscolored.
Deering acts like becoming a water-breather is a huge loss, and a horrible thing. Of course, the two most famous water-breathers in the world are swimming nearby, and don't seem too upset. It's a symptom of Deering's short-sightedness that he doesn't even think of the other side of the problem. He's a scientist, and becoming a water-breather ought to fill him with thrill.
I can't even begin to tell you all the things wrong with Deering stealing whole skyscrapers and putting them on the ocean floor.
Mera comes along just in time and saves Aquaman and Aqualad, then teases them and says she ought to stay with them to keep them out of trouble. As before, her powers are implied to be much more powerful than Aquaman's powers.
Shorts in this issue: a one-page public service cartoon about name-calling and a one-page text piece on "Underwater Oddities"
Even Mera couldn't save this tale.