Tales of Suspense #43

 "Follow me, puny surface man!"

This may, in some ways, be an utterly unremarkable issue. There's still no real supporting cast. The antagonist. Queen Kala of the Netherworld, may not quite be a one-off but she's hardly a major recurring villain. And Tony Stark basically gets out of his quandary by tricking Kala into giving him a laboratory, privacy, and unlimited resources so he can sneakily make a new Iron Man suit- in short, a retread of the origin story.

Plus , again, we have little attention being given to overall continuity, showing that, still, despite the crossovers there's no real conception of a consistent shared universe. The "Netherlanders" (Secretly Dutch? They're certainly below sea level,) are yet another underground civilisation, and they're descended from Atlanteans. So, yeah, I'm sure Mole Man, Tyrannus and indeed the Sub-Mariner might have something to say about that.

Yet, despite its flaws and contemporary quirks (Tony exploits the misogyny of Kala's right hand man! She kindly shows him around before carrying out her plan! Bringing to the surface turns her, conveniently, into an "old hag" so invading the surface wouldn't be viable. Even more conveniently, the effect is reversible!), this is very fun and engaging. But at this point we really, really need a supporting cast and some solid recurring baddies.