Chapter 1: The Man Who Vanquished Aquaman
In Mera's world, a statue is being dedicated to Aquaman. He is put on the spot as an advisor asks if there will be a royal wedding soon. But he's saved by the arrival of Poseidon, who claims to be the brother of Zeus, who has come to take Mera back to his kingdom to rule as his queen.
Mera tells Poseidon that she loves Aquaman, and Poseidon decides to prove he's better by creating a seahorse mount out of a tiny fish. Aquaman controls the seahorse until Poseidon figures it out. Mera still won't go with him, so he turns the seahorse into a dragon and starts to destroy Mera's kingdom.
To save her kingdom, Mera agrees to go with Poseidon. But Aquaman doesn't like that, and attacks Poseidon. Poseidon is about to kill him when Mera intervenes. She and Poseidon vanish intot he past, and Aquaman is blamed for not protecting her, and his new statue is destroyed.
Chapter 2: The Golden Apple of Doom
Before Mera's people get too angry, Aquaman shows them that he stole one of Poseidon's time-pods. He and Aqualad follow Poseidon into the past. There they petition Zeus for the return of Mera. Zeus arranges a contest of skills, and gives Aquaman an amulet to neutralize Poseidon's powers.
Poseidon's friends overhear this, though, and steal the amulet without letting Aquaman know.
Zeus has the pair go after a Golden Apple, and Poseidon immediately uses his bag of tricks to manacle Aquaman to heavy weights. Aquaman escapes, but loses precious time to Poseidon. He finds the vault the apple is supposed to be in, and goes inside... only to be locked in by Poseidon.
Chapter 3: The Creature that Went Berserk
Aquaman uses his telepathy to order fish to get the apple away from Poseidon, and to steal his trident. A giant manta ray frees Aquaman.
When Aquaman returns to Zeus with Poseidon's trident and the apple, Zeus is delighted and amused. But Aquaman explains that he had help, which wasn't allowed by Zeus' rules. Zeus declares Aquaman the winner anyway. In a snit, Poseidon captures Mera and takes her back to the present.
Mera creates a water monster with her powers, but Poseidon temporarily takes her powers away so she can't control it. Unfortunately, the monster then breaks his trident. Aquaman and Aqualad arrive in time to save the pair and destroy the monster. Poseidon realizes he's wrong, and returns to the past with Aquaman's help.
After the growing relationship with Mera in the last few issues, this cover shows someone stealing Mera away from Aquaman (and Aqualad). Enough to get the curious reader to open the book, I suspect.
Poseidon comes from the distant past, but Aquaman and Aqualad are in Mera's parallel dimension. Does this mean that the Greek gods lived in a parallel dimension? This is certainly a very different Poseidon than Aquaman faces in the current series.
Aquaman tells Poseidon that everyone in Atlantis can communicate with fish.
Why don't Mera's people use their powers to stop Poseidon? You'd think they would at least try, but they let the dragon ravage the city, which forces Mera to choose to go with Poseidon. Then they blame Aquaman for not putting up a fight!
Poseidon calls Aquaman "Minnow" as an insult. Funny, that's what Aquaman calls Aqualad later in the book and in his TV series...
Zeus likes Aquaman, and is willing to help him out. He gives Aquaman every advantage.
Shorts and notable ads in this issue: 3/4-page cartoon ad with the Trix Bunny, with the rest of the page taken up with a cartoon quiz, one-page text piece of "Underwater Masters of Disguise", another ad for Lucky Charms, another Rocky and Bullwinkle ad for Cheerios, and a half-page "Cap's Hobby Center" cartoon.
Another good story with an amusing plot device and suitable villain.