Aquaman and Mera are having different visions of Aquababy's future, and arguing about it, when Aquababy wanders off.
Meanwhile, a strange submarine enters the waters around Atlantis, and the three inhabitants discuss conquering the city. The leader, Tamerkhan, is searching for a mate for his daughter Liat. The third is the four-armed warrior Attucka. Tamerkhan and Attucka were in the service of Genghis Khan until his death, then fled to the oceans at the fall of the Khan's empire. Tamerkhan, a great scientist, invented a formula that kept the two alive. He had his daughter Liat with a captured princess. Tamerkhan's science allows the three to live and breathe underwater.
Aquababy sneaks onto the ship and knocks over a potion that makes him grow into a teen-age boy. He then confronts the trio of Mongols, and Attucka is about to kill him when Liat claims him to be her mate.
Aquabab-- er, boy and Liat go out and meet the now searching Aquaman and Mera. They have a hard time adjusting to his sudden age, and to his desire to marry Liat, but they deal and invite the Mongols over to dinner. Aquaman is understandably suspicious, and posts guards around Tamerkhan's Dragon Ship. The guards weapons are stolen by the ship, and they run to warn the city...
In the city, Liat makes Aquaboy pledge love to her alone. He resists, until Tamerkhan hypnotizes him with an amulet. As the guard rushes in to warn Aquaman, he turns to Aquaboy for help, but Aquaboy is on Liat's side now and knocks out Aqualad. Mera appeals to him, but he's too far gone.
Tamerkhan takes Aquaman out onto the balcony to surrender in public, and Mera uses her power to give Aquaman a weapon. But Tamerkhan has a ring that dissolves Mera's creations, and Aquaman is forced to surrender.
Mera spies on the trio, and learns that Aquaboy is in a hypnotic trance, then, when discovered, she throws herself onto Tamerkhan, claiming that Aquaman is too weak for her. She suggests that Aquaman and Attucka have a duel to the death, and once Aquaman is dead, she will marry Tamerkhan.
During the fight, Mera grabs Tamerkhan's amulet, and throws it to the floor, yelling for Aquaman to smash it.
Aquaman smashes the amulet, and is knocked out by Attucka. Aquaboy, with his senses back, rushes to defend his father. Attucka is threatened by Aquaman, but in turn has Aquaboy at his mercy. In addition, Tamerkhan has Mera. Aquaman surrenders to spare Aquaboy, but Attucka wants to kill him anyway. Liat puts an end to that fantasy, and the two go to the alter, Aquaboy no longer willingly.
But the ceremony isn't finished when Aquababy's spell runs off and he becomes a baby again. Tamerkhan gathers equipment to recreate the accident, but Aquababy steals his ring and swallows it. This allows Mera to act, and she frees Aquaman and traps Tamerkhan and Liat in their ship, even as Aquaman punches Attucka onto his own sword.
Mera and Aquaman enter Tamerkhan's ship, and find that they've died, from old age. They push the ship into the Dungeon Depths.
What a cover! Aquaman is battling a mongol with four arms while a young man whose uniform is exactly the reverse of Aquaman's is threatened by the same four-armed sea freak.
Aquaman wants his son to be a great crime fighter, Mera wants him to be a genius scientist.
Second issue in a row where Aquababy sneaks aboard a ship. He's a curious little tyke.
A coloring error on page 12 gives Aquaman a dark shirt like Aquaboy's. On page 19, Aquaboy suddenly has a yellow shirt.
The Dungeon Depths were last mentioned in issue #19.
Shorts and notable ads in this issue: a one-page public service cartoon about the library, a one-page Cheerios ad cartoon featuring Rocky and Bullwinkle, a one-page text piece on "Farmers of the Sea", a half-page "Cap's Hobby Center" cartoon, and a DC subscription ad featuring Metamorpho (who will appear on an Aquaman cover in a few issues).
A fun tale with a grown up Aquababy (who still doesn't have a proper name).