Fantastic Four #219
Leviathans
In Atlantis, Prince Namor the Sub-Mariner is awoken by the sound of his palace coming under torpedo attack and, before he can react, a huge pillar topples onto him and pins him to the floor, allowing two cohorts of Captain Barracuda to make away with the fabled Horn of Atlantis.
Back aboard the villain's submarine, Barracuda reveals his plan to loose the monsters of the deep on New York while he and his men plunder the city. At the Baxter Building, only Ben seems unaffected by the Fantastic Four's latest argument as he settles down to watch what he believes to be a monster movie on television. As the giant creature roams the southern tip of Manhattan, Ben is struck both by the realism of the movie and a sense of familiarity with its protagonist, then finally realizes he is, in fact, watching a news broadcast and that New York is under attack from the monstrous Giganto.
The Fantastic Four are assembled and rush to the scene of the attack where they are met by Namor, who explains the theft of the Horn to Reed. As the Fantastic Four and Namor combine forces they are soon under attack from a horde of other creatures from the depths. As the heroes fight to keep the attackers at bay, Captain Barracuda and his men come ashore intent on plunder.
With Reed, Sue and Ben engaged in defending the city's population from the attack, Johnny and Namor find Barracuda's vessel, gain entry, and wring information from the remaining crew members, who reveal that Barracuda's target is New York's First National Bank. There, Barracuda has something of a change of heart, preferring world domination to mere monetary rewards. Sue accidentally discovers Barracuda and surrounds the Horn in a force field to stop its further use. Deserted by his cronies, Barracuda is easily outnumbered by the heroes and Namor.
Recurring Characters
Fantastic Four (Mister Fantastic, Invisible Girl, Human Torch, Thing), Sub-Mariner, Captain Barracuda, Giganto
Continuity Notes
The Horn of Proteus was last seen in Sub-Mariner #21 during an ill-advised invasion of New York. It was used to summon and then call back a horde of Atlantean beasts.
Some facts about Captain Barracuda in this story:
He mentions his last clash with the Sub-Mariner which occurred in Sub-Mariner #10-11 when Namor prevented him from stealing a sonic device from the Navy.
The Human Torch mentions his past encounter of the Captain, which was his first appearance, back in Strange Tales #120. In that story, the Torch teams up with Iceman to prevent Barracuda from robbing a New York Ferry.
As revealed in Fantastic Four (vol 5) #3 the Gigantos are an entire race of creatures instead of one individual. This story theorizes that this might be the child of the creature killed in Fantastic Four #4.
Namor makes mention of his past romantic interest in Sue, this was first seen in Fantastic Four #4. Sue ultimately chose Reed after the events of Fantastic Four Annual #1 (as clarified in Fantastic Four: The Wedding Special #1) Namor's attempts to win over Sue were ultimately curtailed when Reed and Sue got married in Fantastic Four Annual #3.