Prince Namor, the Sub-Mariner, watches the Hulk's battle with the Living Lightning on his computo-viewer and decides that Hulk would make the perfect ally.
On his way to find the Hulk, Namor unwittingly upsets the plan of the Puppet Master to hijack a Navy Hydrafoil. Vowing revenge, the Puppet Master constructs a Hulk puppet and seizes control of the monster's mind, ordering him to kill the Sub-Mariner.
Hulk smashes his way out of the mound where he was buried (
last issue) and, not recognizing his only friend, knocks down
Rick Jones.
Hulk locates Namor near Key West (island of the Florida Keys, the southern east tip of the USA), and attacks him. There follows a grueling slugging match on land (on the island, and then Miami), in the air, and under the sea which ends only when Hulk hesitates to kill his foe since he lacks the killer instinct.
Sub-Mariner summons a tidal wave to overwhelm his enemy which has an unintended consequence: It also engulfs and destroys the Puppet Masters hidden lair. Freed from the villains control, Hulk reverts to the form of Bruce Banner. Namor comes seeking his adversary but finding only an ordinary man, returns to the sea.